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Zebardastan N, Bradford J, Lipton-Duffin J, MacLeod J, Ostrikov KK, Tomellini M, Motta N. High quality epitaxial graphene on 4H-SiC by face-to-face growth in ultra-high vacuum. Nanotechnology 2022; 34:105601. [PMID: 36562509 DOI: 10.1088/1361-6528/aca8b2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 12/05/2022] [Indexed: 06/17/2023]
Abstract
Epitaxial graphene on SiC is the most promising substrate for the next generation 2D electronics, due to the possibility to fabricate 2D heterostructures directly on it, opening the door to the use of all technological processes developed for silicon electronics. To obtain a suitable material for large scale applications, it is essential to achieve perfect control of size, quality, growth rate and thickness. Here we show that this control on epitaxial graphene can be achieved by exploiting the face-to-face annealing of SiC in ultra-high vacuum. With this method, Si atoms trapped in the narrow space between two SiC wafers at high temperatures contribute to the reduction of the Si sublimation rate, allowing to achieve smooth and virtually defect free single graphene layers. We analyse the products obtained on both on-axis and off-axis 4H-SiC substrates in a wide range of temperatures (1300 °C-1500 °C), determining the growth law with the help of x-ray photoelectron spectroscopy (XPS). Our epitaxial graphene on SiC has terrace widths up to 10μm (on-axis) and 500 nm (off-axis) as demonstrated by atomic force microscopy and scanning tunnelling microscopy, while XPS and Raman spectroscopy confirm high purity and crystalline quality.
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Affiliation(s)
- Negar Zebardastan
- School of Chemistry and Physics, Queensland University of Technology, Brisbane 4000, QLD, Australia
- Centre for Materials Science, Queensland University of Technology, Brisbane 4000, QLD, Australia
| | - Jonathan Bradford
- School of Chemistry and Physics, Queensland University of Technology, Brisbane 4000, QLD, Australia
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Josh Lipton-Duffin
- School of Chemistry and Physics, Queensland University of Technology, Brisbane 4000, QLD, Australia
- Centre for Materials Science, Queensland University of Technology, Brisbane 4000, QLD, Australia
| | - Jennifer MacLeod
- School of Chemistry and Physics, Queensland University of Technology, Brisbane 4000, QLD, Australia
- Centre for Materials Science, Queensland University of Technology, Brisbane 4000, QLD, Australia
| | - Kostya Ken Ostrikov
- School of Chemistry and Physics, Queensland University of Technology, Brisbane 4000, QLD, Australia
- Centre for Materials Science, Queensland University of Technology, Brisbane 4000, QLD, Australia
| | - Massimo Tomellini
- Dipartimento di Scienze eTecnologie Chimiche, Università degli Studi di Roma Tor Vergata, Via della Ricerca Scientifica, I-00133 Rome, Italy
- Istitutodi Struttura della Materia, CNR, Via Fosso del Cavaliere 100, I-00133 Rome, Italy
| | - Nunzio Motta
- School of Chemistry and Physics, Queensland University of Technology, Brisbane 4000, QLD, Australia
- Centre for Materials Science, Queensland University of Technology, Brisbane 4000, QLD, Australia
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2
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van Beest MRRS, Arpino F, Hlinka O, Sauret E, van Beest NRTP, Humphries RS, Buonanno G, Morawska L, Governatori G, Motta N. Influence of indoor airflow on particle spread of a single breath and cough in enclosures: Does opening a window really 'help'? Atmos Pollut Res 2022; 13:101473. [PMID: 35692900 PMCID: PMC9167821 DOI: 10.1016/j.apr.2022.101473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 05/27/2022] [Accepted: 05/29/2022] [Indexed: 06/15/2023]
Abstract
The spread of respiratory diseases via aerosol particles in indoor settings is of significant concern. The SARS-CoV-2 virus has been found to spread widely in confined enclosures like hotels, hospitals, cruise ships, prisons, and churches. Particles exhaled from a person indoors can remain suspended long enough for increasing the opportunity for particles to spread spatially. Careful consideration of the ventilation system is essential to minimise the spread of particles containing infectious pathogens. Previous studies have shown that indoor airflow induced by opened windows would minimise the spread of particles. However, how outdoor airflow through an open window influences the indoor airflow has not been considered. The aim of this study is to provide a clear understanding of the indoor particle spread across multiple rooms, in a situation similar to what is found in quarantine hotels and cruise ships, using a combination of HVAC (Heating, Ventilation and Air-Conditioning) ventilation and an opening window. Using a previously validated mathematical model, we used 3D CFD (computational fluid dynamics) simulations to investigate to what extent different indoor airflow scenarios contribute to the transport of a single injection of particles ( 1 . 3 μ m ) in a basic 3D multi-room indoor environment. Although this study is limited to short times, we demonstrate that in certain conditions approximately 80% of the particles move from one room to the corridor and over 60% move to the nearby room within 5 to 15 s. Our results provide additional information to help identifying relevant recommendations to limit particles from spreading in enclosures.
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Affiliation(s)
- M R R S van Beest
- School of Chemistry and Physics, Queensland University of Technology, Brisbane, Australia
- Software Systems Group, CSIRO | DATA61, Brisbane, Queensland, Australia
| | - F Arpino
- Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Cassino, Italy
| | - O Hlinka
- Information Management & Technology (IM&T), CSIRO, Pullenvale, Queensland, Australia
| | - E Sauret
- School of Mechanical, Medical and Process Engineering, Queensland University of Technology, Brisbane, Australia
| | - N R T P van Beest
- Software Systems Group, CSIRO | DATA61, Brisbane, Queensland, Australia
| | - R S Humphries
- Climate Science Centre, CSIRO Oceans and Atmosphere, Aspendale, Victoria, Australia
| | - G Buonanno
- Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Cassino, Italy
| | - L Morawska
- School of Earth and Atmospheric Sciences, Queensland University of Technology, Brisbane, Australia
| | - G Governatori
- Software Systems Group, CSIRO | DATA61, Brisbane, Queensland, Australia
| | - N Motta
- School of Chemistry and Physics, Queensland University of Technology, Brisbane, Australia
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3
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Li W, Shahbazi M, Xing K, Tesfamichael T, Motta N, Qi DC. Highly Sensitive NO2 Gas Sensors Based on MoS2@MoO3 Magnetic Heterostructure. Nanomaterials 2022; 12:nano12081303. [PMID: 35458010 PMCID: PMC9027905 DOI: 10.3390/nano12081303] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 04/07/2022] [Accepted: 04/08/2022] [Indexed: 12/16/2022]
Abstract
Recently, two-dimensional (2D) materials and their heterostructures have attracted considerable attention in gas sensing applications. In this work, we synthesized 2D MoS2@MoO3 heterostructures through post-sulfurization of α-MoO3 nanoribbons grown via vapor phase transport (VPT) and demonstrated highly sensitive NO2 gas sensors based on the hybrid heterostructures. The morphological, structural, and compositional properties of the MoS2@MoO3 hybrids were studied by a combination of advanced characterization techniques revealing a core-shell structure with the coexistence of 2H-MoS2 multilayers and intermediate molybdenum oxysulfides on the surface of α-MoO3. The MoS2@MoO3 hybrids also exhibit room-temperature ferromagnetism, revealed by vibrating sample magnetometry (VSM), as a result of the sulfurization process. The MoS2@MoO3 gas sensors display a p-type-like response towards NO2 with a detection limit of 0.15 ppm at a working temperature of 125 °C, as well as superb selectivity and reversibility. This p-type-like sensing behavior is attributed to the heterointerface of MoS2-MoO3 where interfacial charge transfer leads to a p-type inversion layer in MoS2, and is enhanced by magnetic dipole interactions between the paramagnetic NO2 and the ferromagnetic sensing layer. Our study demonstrates the promising application of 2D molybdenum hybrid compounds in gas sensing applications with a unique combination of electronic and magnetic properties.
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Affiliation(s)
- Wei Li
- School of Chemistry and Physics, Queensland University of Technology, Brisbane, QLD 4001, Australia; (W.L.); (M.S.)
- Centre for Materials Science, Queensland University of Technology, Brisbane, QLD 4001, Australia
| | - Mahboobeh Shahbazi
- School of Chemistry and Physics, Queensland University of Technology, Brisbane, QLD 4001, Australia; (W.L.); (M.S.)
| | - Kaijian Xing
- School of Physics and Astronomy, Monash University, Clayton, VIC 3800, Australia;
| | - Tuquabo Tesfamichael
- Centre for Materials Science, Queensland University of Technology, Brisbane, QLD 4001, Australia
- School of Mechanical, Medical and Process Engineering, Queensland University of Technology, Brisbane, QLD 4001, Australia
- Correspondence: (T.T.); (N.M.); (D.-C.Q.)
| | - Nunzio Motta
- School of Chemistry and Physics, Queensland University of Technology, Brisbane, QLD 4001, Australia; (W.L.); (M.S.)
- Centre for Materials Science, Queensland University of Technology, Brisbane, QLD 4001, Australia
- Correspondence: (T.T.); (N.M.); (D.-C.Q.)
| | - Dong-Chen Qi
- School of Chemistry and Physics, Queensland University of Technology, Brisbane, QLD 4001, Australia; (W.L.); (M.S.)
- Centre for Materials Science, Queensland University of Technology, Brisbane, QLD 4001, Australia
- Correspondence: (T.T.); (N.M.); (D.-C.Q.)
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4
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Ashok A, Vasanth A, Nagaura T, Eguchi M, Motta N, Phan HP, Nguyen NT, Shapter JG, Na J, Yamauchi Y. Plasma-Induced Nanocrystalline Domain Engineering and Surface Passivation in Mesoporous Chalcogenide Semiconductor Thin Films. Angew Chem Int Ed Engl 2022; 61:e202114729. [PMID: 35080101 PMCID: PMC9305943 DOI: 10.1002/anie.202114729] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Indexed: 11/17/2022]
Abstract
The synthesis of highly crystalline mesoporous materials is key to realizing high‐performance chemical and biological sensors and optoelectronics. However, minimizing surface oxidation and enhancing the domain size without affecting the porous nanoarchitecture are daunting challenges. Herein, we report a hybrid technique that combines bottom‐up electrochemical growth with top‐down plasma treatment to produce mesoporous semiconductors with large crystalline domain sizes and excellent surface passivation. By passivating unsaturated bonds without incorporating any chemical or physical layers, these films show better stability and enhancement in the optoelectronic properties of mesoporous copper telluride (CuTe) with different pore diameters. These results provide exciting opportunities for the development of long‐term, stable, and high‐performance mesoporous semiconductor materials for future technologies.
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Affiliation(s)
- Aditya Ashok
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, Queensland, 4072, Australia.,Queensland Micro- and Nanotechnology Centre, Griffith University, Nathan, Queensland, 4111, Australia
| | - Arya Vasanth
- Amrita Center for Nanosciences and Molecular Medicine, Amrita Vishwa Vidyapeetham, Kochi, Kerala, 682041, India
| | - Tomota Nagaura
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, Queensland, 4072, Australia
| | - Miharu Eguchi
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, Queensland, 4072, Australia.,JST-ERATO Yamauchi Material Space-Tectonics Project and International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki, 305-0044, Japan
| | - Nunzio Motta
- School of Chemistry and Physics, Queensland University of Technology (QUT), 2 George Street, Brisbane, Queensland, 4001, Australia
| | - Hoang-Phuong Phan
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, Queensland, 4072, Australia.,Queensland Micro- and Nanotechnology Centre, Griffith University, Nathan, Queensland, 4111, Australia
| | - Nam-Trung Nguyen
- Queensland Micro- and Nanotechnology Centre, Griffith University, Nathan, Queensland, 4111, Australia
| | - Joseph G Shapter
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, Queensland, 4072, Australia
| | - Jongbeom Na
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, Queensland, 4072, Australia.,Research and Development (R&D) Division, Green Energy Institute, Mokpo, Jeollanamdo, 58656, Republic of Korea
| | - Yusuke Yamauchi
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, Queensland, 4072, Australia.,JST-ERATO Yamauchi Material Space-Tectonics Project and International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki, 305-0044, Japan
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5
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Ashok A, Vasanth A, Nagaura T, Eguchi M, Motta N, Phan H, Nguyen N, Shapter JG, Na J, Yamauchi Y. Plasma‐Induced Nanocrystalline Domain Engineering and Surface Passivation in Mesoporous Chalcogenide Semiconductor Thin Films. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202114729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Aditya Ashok
- Australian Institute for Bioengineering and Nanotechnology (AIBN) The University of Queensland Brisbane Queensland 4072 Australia
- Queensland Micro- and Nanotechnology Centre Griffith University Nathan Queensland 4111 Australia
| | - Arya Vasanth
- Amrita Center for Nanosciences and Molecular Medicine Amrita Vishwa Vidyapeetham Kochi Kerala 682041 India
| | - Tomota Nagaura
- Australian Institute for Bioengineering and Nanotechnology (AIBN) The University of Queensland Brisbane Queensland 4072 Australia
| | - Miharu Eguchi
- Australian Institute for Bioengineering and Nanotechnology (AIBN) The University of Queensland Brisbane Queensland 4072 Australia
- JST-ERATO Yamauchi Material Space-Tectonics Project and International Center for Materials Nanoarchitectonics (WPI-MANA) National Institute for Materials Science 1-1 Namiki, Tsukuba Ibaraki 305-0044 Japan
| | - Nunzio Motta
- School of Chemistry and Physics Queensland University of Technology (QUT) 2 George Street Brisbane Queensland 4001 Australia
| | - Hoang‐Phuong Phan
- Australian Institute for Bioengineering and Nanotechnology (AIBN) The University of Queensland Brisbane Queensland 4072 Australia
- Queensland Micro- and Nanotechnology Centre Griffith University Nathan Queensland 4111 Australia
| | - Nam‐Trung Nguyen
- Queensland Micro- and Nanotechnology Centre Griffith University Nathan Queensland 4111 Australia
| | - Joseph G. Shapter
- Australian Institute for Bioengineering and Nanotechnology (AIBN) The University of Queensland Brisbane Queensland 4072 Australia
| | - Jongbeom Na
- Australian Institute for Bioengineering and Nanotechnology (AIBN) The University of Queensland Brisbane Queensland 4072 Australia
- Research and Development (R&D) Division Green Energy Institute Mokpo Jeollanamdo 58656 Republic of Korea
| | - Yusuke Yamauchi
- Australian Institute for Bioengineering and Nanotechnology (AIBN) The University of Queensland Brisbane Queensland 4072 Australia
- JST-ERATO Yamauchi Material Space-Tectonics Project and International Center for Materials Nanoarchitectonics (WPI-MANA) National Institute for Materials Science 1-1 Namiki, Tsukuba Ibaraki 305-0044 Japan
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6
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Amjadipour M, Bradford J, Zebardastan N, Motta N, Iacopi F. MoS 2/Epitaxial graphene layered electrodes for solid-state supercapacitors. Nanotechnology 2021; 32:195401. [PMID: 33524969 DOI: 10.1088/1361-6528/abe1f1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The potential of transition metal dichalcogenides such as MoS2 for energy storage has been significantly limited so far by the lack of conductivity and structural stability. Employing highly conductive, graphitic materials in combination with transition metal dichalcogenides can address this gap. Here, we explore the use of a layered electrode structure for solid-state supercapacitors, made of MoS2 and epitaxial graphene (EG) on cubic silicon carbide for on-silicon energy storage. We show that the energy storage of the solid-state supercapacitors can be significantly increased by creating layered MoS2/graphene electrodes, yielding a substantial improvement as compared to electrodes using either EG or MoS2 alone. We conclude that the conductivity of EG and the growth morphology of MoS2 on graphene play an enabling role in the successful use of transition metal dichalcogenides for on-chip energy storage.
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Affiliation(s)
- Mojtaba Amjadipour
- School of Electrical and Data Engineering, Faculty of Engineering and Information Technology, University of Technology Sydney, NSW, Australia
| | - Jonathan Bradford
- School of Chemistry and Physics, Science and Engineering Faculty, Queensland University of Technology, QLD, Australia
- School of Physics & Astronomy, University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Negar Zebardastan
- School of Chemistry and Physics, Science and Engineering Faculty, Queensland University of Technology, QLD, Australia
- Centre for Materials Science, Queensland University of Technology, QLD, Australia
| | - Nunzio Motta
- School of Chemistry and Physics, Science and Engineering Faculty, Queensland University of Technology, QLD, Australia
- Centre for Materials Science, Queensland University of Technology, QLD, Australia
| | - Francesca Iacopi
- School of Electrical and Data Engineering, Faculty of Engineering and Information Technology, University of Technology Sydney, NSW, Australia
- Centre for Clean Energy Technology, University of Technology Sydney, NSW, Australia
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7
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Jayaramulu K, Horn M, Schneemann A, Saini H, Bakandritsos A, Ranc V, Petr M, Stavila V, Narayana C, Scheibe B, Kment Š, Otyepka M, Motta N, Dubal D, Zbořil R, Fischer RA. Covalent Graphene-MOF Hybrids for High-Performance Asymmetric Supercapacitors. Adv Mater 2021; 33:e2004560. [PMID: 33274794 DOI: 10.1002/adma.202004560] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 10/29/2020] [Indexed: 06/12/2023]
Abstract
In this work, the covalent attachment of an amine functionalized metal-organic framework (UiO-66-NH2 = Zr6 O4 (OH)4 (bdc-NH2 )6 ; bdc-NH2 = 2-amino-1,4-benzenedicarboxylate) (UiO-Universitetet i Oslo) to the basal-plane of carboxylate functionalized graphene (graphene acid = GA) via amide bonds is reported. The resultant GA@UiO-66-NH2 hybrid displayed a large specific surface area, hierarchical pores and an interconnected conductive network. The electrochemical characterizations demonstrated that the hybrid GA@UiO-66-NH2 acts as an effective charge storing material with a capacitance of up to 651 F g-1 , significantly higher than traditional graphene-based materials. The results suggest that the amide linkage plays a key role in the formation of a π-conjugated structure, which facilitates charge transfer and consequently offers good capacitance and cycling stability. Furthermore, to realize the practical feasibility, an asymmetric supercapacitor using a GA@UiO-66-NH2 positive electrode with Ti3 C2 TX MXene as the opposing electrode has been constructed. The cell is able to deliver a power density of up to 16 kW kg-1 and an energy density of up to 73 Wh kg-1 , which are comparable to several commercial devices such as Pb-acid and Ni/MH batteries. Under an intermediate level of loading, the device retained 88% of its initial capacitance after 10 000 cycles.
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Affiliation(s)
- Kolleboyina Jayaramulu
- Department of Chemistry, Indian Institute of Technology Jammu, Nagrota, Jammu & Kashmir, 181221, India
- Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacky University, Šlechtitelů 27, Olomouc, 78371, Czech Republic
- Chair of Inorganic and Metal-Organic Chemistry, Department of Chemistry and Catalysis Research Centre, Technical University of Munich, Garching, 85748, Germany
| | - Michael Horn
- School of Chemistry and Physics, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD, 4001, Australia
| | - Andreas Schneemann
- Inorganic Chemistry, Department of Chemistry and Food Chemistry, Technische Universität Dresden, Bergstr. 66, Dresden, 01069, Germany
| | - Haneesh Saini
- Department of Chemistry, Indian Institute of Technology Jammu, Nagrota, Jammu & Kashmir, 181221, India
| | - Aristides Bakandritsos
- Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacky University, Šlechtitelů 27, Olomouc, 78371, Czech Republic
- Nanotechnology Centre, VŠB-Technical University of Ostrava, 17. listopadu 2172/15, Ostrava-Poruba, 708 00, Czech Republic
| | - Vaclav Ranc
- Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacky University, Šlechtitelů 27, Olomouc, 78371, Czech Republic
| | - Martin Petr
- Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacky University, Šlechtitelů 27, Olomouc, 78371, Czech Republic
| | - Vitalie Stavila
- Sandia National Laboratories, 7011 East Avenue, MS9161, Livermore, CA, 94550, USA
| | - Chandrabhas Narayana
- Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur, Bangalore, 560064, India
| | - Błażej Scheibe
- Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacky University, Šlechtitelů 27, Olomouc, 78371, Czech Republic
- Adam Mickiewicz University in Poznań, NanoBioMedical Centre, Wszechnicy Piastowskiej 3, Poznań, PL61614, Poland
| | - Štěpán Kment
- Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacky University, Šlechtitelů 27, Olomouc, 78371, Czech Republic
- Nanotechnology Centre, VŠB-Technical University of Ostrava, 17. listopadu 2172/15, Ostrava-Poruba, 708 00, Czech Republic
| | - Michal Otyepka
- Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacky University, Šlechtitelů 27, Olomouc, 78371, Czech Republic
| | - Nunzio Motta
- School of Chemistry and Physics, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD, 4001, Australia
| | - Deepak Dubal
- School of Chemistry and Physics, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD, 4001, Australia
| | - Radek Zbořil
- Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacky University, Šlechtitelů 27, Olomouc, 78371, Czech Republic
- Nanotechnology Centre, VŠB-Technical University of Ostrava, 17. listopadu 2172/15, Ostrava-Poruba, 708 00, Czech Republic
| | - Roland A Fischer
- Chair of Inorganic and Metal-Organic Chemistry, Department of Chemistry and Catalysis Research Centre, Technical University of Munich, Garching, 85748, Germany
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8
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Fusco Z, Rahmani M, Tran-Phu T, Ricci C, Kiy A, Kluth P, Della Gaspera E, Motta N, Neshev D, Tricoli A. Photonic Fractal Metamaterials: A Metal-Semiconductor Platform with Enhanced Volatile-Compound Sensing Performance. Adv Mater 2020; 32:e2002471. [PMID: 33089556 DOI: 10.1002/adma.202002471] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 09/16/2020] [Indexed: 06/11/2023]
Abstract
Advance of photonics media is restrained by the lack of structuring techniques for the 3D fabrication of active materials with long-range periodicity. A methodology is reported for the engineering of tunable resonant photonic media with thickness exceeding the plasmonic near-field enhancement region by more than two orders of magnitude. The media architecture consists of a stochastically ordered distribution of plasmonic nanocrystals in a fractal scaffold of high-index semiconductors. This plasmonic-semiconductor fractal media supports the propagation of surface plasmons with drastically enhanced intensity over multiple length scales, overcoming the 2D limitations of established metasurface technologies. The fractal media are used for the fabrication of plasmonic optical gas sensors, achieving a limit of detection of 0.01 vol% at room temperature and sensitivity up to 1.9 nm vol%-1 , demonstrating almost a fivefold increase with respect to an optimized planar geometry. Beneficially to their implementation, the self-assembly mechanism of this fractal architecture allows fabrication of micrometer-thick media over surfaces of several square centimeters in a few seconds. The designable optical features and intrinsic scalability of these photonic fractal metamaterials provide ample opportunities for applications, bridging across transformation optics, sensing, and light harvesting.
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Affiliation(s)
- Zelio Fusco
- Nanotechnology Research Laboratory, College of Engineering and Computer Science, The Australian National University, Canberra, ACT, 2601, Australia
| | - Mohsen Rahmani
- Advanced Optics and Photonics Laboratory, Department of Engineering, School of Science and Technology, Nottingham Trent University, Nottingham, NG11 8NS, UK
| | - Thanh Tran-Phu
- Nanotechnology Research Laboratory, College of Engineering and Computer Science, The Australian National University, Canberra, ACT, 2601, Australia
| | - Chiara Ricci
- Nanotechnology Research Laboratory, College of Engineering and Computer Science, The Australian National University, Canberra, ACT, 2601, Australia
| | - Alexander Kiy
- Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra, ACT, 2601, Australia
| | - Patrick Kluth
- Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra, ACT, 2601, Australia
| | | | - Nunzio Motta
- Institute for Future Environments and School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD, 4001, Australia
| | - Dragomir Neshev
- ARC Centre of Excellence for Transformative Meta-Optical Systems, Research School of Physics, Australian National University, Canberra, ACT, 2601, Australia
| | - Antonio Tricoli
- Nanotechnology Research Laboratory, College of Engineering and Computer Science, The Australian National University, Canberra, ACT, 2601, Australia
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9
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Bradford J, Shafiei M, MacLeod J, Motta N. Synthesis and characterization of WS 2/graphene/SiC van der Waals heterostructures via WO 3-x thin film sulfurization. Sci Rep 2020; 10:17334. [PMID: 33060655 PMCID: PMC7567119 DOI: 10.1038/s41598-020-74024-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 09/15/2020] [Indexed: 11/28/2022] Open
Abstract
Van der Waals heterostructures of monolayer transition metal dichalcogenides (TMDs) and graphene have attracted keen scientific interest due to the complementary properties of the materials, which have wide reaching technological applications. Direct growth of uniform, large area TMDs on graphene substrates by chemical vapor deposition (CVD) is limited by slow lateral growth rates, which result in a tendency for non-uniform multilayer growth. In this work, monolayer and few-layer WS2 was grown on epitaxial graphene on SiC by sulfurization of WO3−x thin films deposited directly onto the substrate. Using this method, WS2 growth was achieved at temperatures as low as 700 °C – significantly less than the temperature required for conventional CVD. Achieving long-range uniformity remains a challenge, but this process could provide a route to synthesize a broad range of TMD/graphene van der Waals heterostructures with novel properties and functionality not accessible by conventional CVD growth.
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Affiliation(s)
- Jonathan Bradford
- School of Chemistry and Physics, Queensland University of Technology (QUT), Brisbane, QLD, Australia.,School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Mahnaz Shafiei
- Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, VIC, Australia.,Institute for Future Environments, Queensland University of Technology (QUT), Brisbane, QLD, Australia
| | - Jennifer MacLeod
- School of Chemistry and Physics, Queensland University of Technology (QUT), Brisbane, QLD, Australia.,Institute for Future Environments, Queensland University of Technology (QUT), Brisbane, QLD, Australia.,Centre for Materials Science, Queensland University of Technology (QUT), Brisbane, QLD, Australia
| | - Nunzio Motta
- School of Chemistry and Physics, Queensland University of Technology (QUT), Brisbane, QLD, Australia. .,Institute for Future Environments, Queensland University of Technology (QUT), Brisbane, QLD, Australia. .,Centre for Materials Science, Queensland University of Technology (QUT), Brisbane, QLD, Australia.
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10
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Horn MR, Williams F, Dubal D, MacLeod J, Motta N. Simple Method for Estimating the Surface Area of Layered Graphene-Based Thin Films. ChemSusChem 2020; 13:1613-1620. [PMID: 31532573 DOI: 10.1002/cssc.201901928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 09/17/2019] [Indexed: 06/10/2023]
Abstract
Thin films, papers, or foils produced from graphene-based materials have been the focus of considerable research interest in recent years. They have a range of applications including energy storage, selective filtration of liquids, and gas storage. For all of these applications, the critical attribute of the films is their pore volume. However, there remains a considerable challenge around characterizing the accessible microscopic surface area of the materials in their intended state of application. In this work, an image-processing-based approach is presented for estimating the lower threshold of specific surface area for graphene-based films that have a typical multilayered structure. Canny edge detection is used together with tortuosity measurements to infer sheet areas from layer edges. The method serves as a simple independent characterization technique. Specific surface area values predicted for a range of similar films vary by less than 4× the reported values, which vary by >1.1×103 in range.
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Affiliation(s)
- Michael R Horn
- Queensland University of Technology, 2 George St., Brisbane, 4001, QLD, Australia
| | - Fraser Williams
- Queensland University of Technology, 2 George St., Brisbane, 4001, QLD, Australia
| | - Deepak Dubal
- Queensland University of Technology, 2 George St., Brisbane, 4001, QLD, Australia
| | - Jennifer MacLeod
- Queensland University of Technology, 2 George St., Brisbane, 4001, QLD, Australia
| | - Nunzio Motta
- Queensland University of Technology, 2 George St., Brisbane, 4001, QLD, Australia
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11
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Hartl H, MacLeod J, O'Mullane AP, Motta N, Ostrikov KK. Multiscale Plasma-Catalytic On-Surface Assembly. Small 2020; 16:e1903184. [PMID: 31433111 DOI: 10.1002/smll.201903184] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 07/15/2019] [Indexed: 06/10/2023]
Abstract
Controlled modification of surfaces is one of the key pursuits of the nanoscience and nanotechnology fields, allowing for the fabrication of bespoke materials with targeted functionalities. However, many surface modifications currently require painstakingly precise and/or energy intensive processing to implement, and are thus limited in scope and scale. Here, a concept which can enhance the capacity for control of surfaces is introduced: plasma-assisted nucleation and self-assembly at atomic to nanoscales, scalable at atmospheric pressures.
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Affiliation(s)
- Hugo Hartl
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD, 4000, Australia
| | - Jennifer MacLeod
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD, 4000, Australia
| | - Anthony P O'Mullane
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD, 4000, Australia
| | - Nunzio Motta
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD, 4000, Australia
| | - Kostya Ken Ostrikov
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD, 4000, Australia
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12
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Liu B, Bo R, Taheri M, Di Bernardo I, Motta N, Chen H, Tsuzuki T, Yu G, Tricoli A. Metal-Organic Frameworks/Conducting Polymer Hydrogel Integrated Three-Dimensional Free-Standing Monoliths as Ultrahigh Loading Li-S Battery Electrodes. Nano Lett 2019; 19:4391-4399. [PMID: 31246030 DOI: 10.1021/acs.nanolett.9b01033] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The lithium-sulfur (Li-S) system is a promising material for the next-generation of high energy density batteries with application extending from electrical vehicles to portable devices and aeronautics. Despite progress, the energy density of current Li-S technologies is still below that of conventional intercalation-type cathode materials due to limited stability and utilization efficiency at high sulfur loading. Here, we present a conducting polymer hydrogel integrated highly performing free-standing three-dimensional (3D) monolithic electrode architecture for Li-S batteries with superior electrochemical stability and energy density. The electrode layout consists of a highly conductive three-dimensional network of N,P codoped carbon with well-dispersed metal-organic framework nanodomains of ZIF-67 and HKUST-1. The hierarchical monolithic 3D carbon networks provide an excellent environment for charge and electrolyte transport as well as mechanical and chemical stability. The electrically integrated MOF nanodomains significantly enhance the sulfur loading and retention capabilities by inhibiting the release of lithium polysulfide specificities as well as improving the charge transfer efficiency at the electrolyte interface. Our optimal 3D carbon-HKUST-1 electrode architecture achieves a very high areal capacity of >16 mAh cm-2 and volumetric capacity (CV) of 1230.8 mAh cm-3 with capacity retention of 82% at 0.2C for over 300 cycles, providing an attractive candidate material for future high-energy density Li-S batteries.
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Affiliation(s)
| | | | | | | | - Nunzio Motta
- School of Chemistry, Physics, and Mechanical Engineering , Queensland University of Technology , Brisbane , QLD 4001 , Australia
| | | | | | - Guihua Yu
- Materials Science and Engineering Program and Department of Mechanical Engineering , The University of Texas at Austin , Austin , Texas 78712 , United States
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13
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Abyazisani M, Bradford J, Motta N, Lipton-Duffin J, MacLeod J. Adsorption, Deprotonation, and Decarboxylation of Isophthalic Acid on Cu(111). Langmuir 2019; 35:7112-7120. [PMID: 31117744 DOI: 10.1021/acs.langmuir.8b04233] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The surface-assisted reaction of rationally designed organic precursors is an emerging approach toward fabricating atomically precise nanostructures. Recently, on-surface decarboxylation has attracted attention due to its volatile by-products, which tend to leave the surface during the reaction means only the desired products are retained on the surface. However, in addition to acting as the reactive site, the carboxylic acid groups play a vital role in the adsorption configuration of small-molecule molecular precursors and therefore in the reaction pathways. Here, scanning tunnelling microscopy (STM), synchrotron radiation photoelectron spectroscopy (SRPES), and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy have been employed to characterize the monodeprotonated, fully deprotonated, and decarboxylated products of isophthalic acid (IPA) on Cu(111). IPA is partially reacted (monodeprotonated) upon adsorption on Cu(111) at room temperature. Angular-dependent X-ray photoelectron spectroscopy reveals that IPA initially anchors to the surface via the carboxylate group. After annealing, the molecule fully deprotonates and reorients so that it anchors to the surface via both carboxylate groups in a bipodal configuration. NEXAFS confirms that the molecule is tilted upon adsorption and after full deprotonation. Following decarboxylation, the flat-lying molecule forms into oligomeric motifs on the surface. This work demonstrates the importance of molecular adsorption geometry for on-surface reactions.
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14
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Amjadipour M, MacLeod J, Lipton-Duffin J, Tadich A, Boeckl JJ, Iacopi F, Motta N. Electron effective attenuation length in epitaxial graphene on SiC. Nanotechnology 2019; 30:025704. [PMID: 30382023 DOI: 10.1088/1361-6528/aae7ec] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The inelastic mean free path (IMFP) for carbon-based materials is notoriously challenging to model, and moving from bulk materials to 2D materials may exacerbate this problem, making the accurate measurements of IMFP in 2D carbon materials critical. The overlayer-film method is a common experimental method to estimate IMFP by measuring electron effective attenuation length (EAL). This estimation relies on an assumption that elastic scattering effects are negligible. We report here an experimental measurement of electron EAL in epitaxial graphene on SiC using photoelectron spectroscopy over an electron kinetic energy range of 50-1150 eV. We find a significant effect of the interface between the 2D carbon material and the substrate, indicating that the attenuation length in the so-called 'buffer layer' is smaller than for free-standing graphene. Our results also suggest that the existing models for estimating IMFPs may not adequately capture the physics of electron interactions in 2D materials.
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Affiliation(s)
- Mojtaba Amjadipour
- School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty, Queensland University of Technology, Brisbane, QLD, Australia
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15
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Khoshsirat N, Ali F, Tiing Tiong V, Amjadipour M, Wang H, Shafiei M, Motta N. Optimization of Mo/Cr bilayer back contacts for thin-film solar cells. Beilstein J Nanotechnol 2018; 9:2700-2707. [PMID: 30416921 PMCID: PMC6204819 DOI: 10.3762/bjnano.9.252] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 09/21/2018] [Indexed: 06/09/2023]
Abstract
Molybdenum (Mo) is the most commonly used material as back contact in thin-film solar cells. Adhesion of Mo film to soda-lime glass (SLG) substrate is crucial to the performance of solar cells. In this study, an optimized bilayer structure made of a thin layer of Mo on an ultra-thin chromium (Cr) adhesion layer is used as the back contact for a copper zinc tin sulfide (CZTS) thin-film solar cell on a SLG substrate. DC magnetron sputtering is used for deposition of Mo and Cr films. The conductivity of Mo/Cr bilayer films, their microstructure and surface morphology are studied at different deposition powers and working pressures. Good adhesion to the SLG substrate has been achieved by means of an ultra-thin Cr layer under the Mo layer. By optimizing the deposition conditions we achieved low surface roughness, high optical reflectance and low sheet resistivity while we could decrease the back contact thickness to 600 nm. That is two thirds to half of the thickness that is currently being used for bilayer and single layer back contact for thin-film solar cells. We demonstrate the excellent properties of Mo/Cr bilayer as back contact of a CZTS solar cell.
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Affiliation(s)
- Nima Khoshsirat
- School of Chemistry, Physics, Mechanical Engineering, Queensland University of Technology (QUT), Brisbane, Australia
| | - Fawad Ali
- School of Chemistry, Physics, Mechanical Engineering, Queensland University of Technology (QUT), Brisbane, Australia
| | - Vincent Tiing Tiong
- School of Chemistry, Physics, Mechanical Engineering, Queensland University of Technology (QUT), Brisbane, Australia
| | - Mojtaba Amjadipour
- School of Chemistry, Physics, Mechanical Engineering, Queensland University of Technology (QUT), Brisbane, Australia
| | - Hongxia Wang
- School of Chemistry, Physics, Mechanical Engineering, Queensland University of Technology (QUT), Brisbane, Australia
| | - Mahnaz Shafiei
- School of Chemistry, Physics, Mechanical Engineering, Queensland University of Technology (QUT), Brisbane, Australia
- Swinburne University of Technology, Melbourne, Australia
| | - Nunzio Motta
- School of Chemistry, Physics, Mechanical Engineering, Queensland University of Technology (QUT), Brisbane, Australia
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16
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Imran M, Motta N, Shafiei M. Electrospun one-dimensional nanostructures: a new horizon for gas sensing materials. Beilstein J Nanotechnol 2018; 9:2128-2170. [PMID: 30202686 PMCID: PMC6122236 DOI: 10.3762/bjnano.9.202] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 07/23/2018] [Indexed: 05/24/2023]
Abstract
Electrospun one-dimensional (1D) nanostructures are rapidly emerging as key enabling components in gas sensing due to their unique electrical, optical, magnetic, thermal, mechanical and chemical properties. 1D nanostructures have found applications in numerous areas, including healthcare, energy storage, biotechnology, environmental monitoring, and defence/security. Their enhanced specific surface area, superior mechanical properties, nanoporosity and improved surface characteristics (in particular, uniformity and stability) have made them important active materials for gas sensing applications. Such highly sensitive and selective elements can be embedded in sensor nodes for internet-of-things applications or in mobile systems for continuous monitoring of air pollutants and greenhouse gases as well as for monitoring the well-being and health in everyday life. Herein, we review recent developments of gas sensors based on electrospun 1D nanostructures in different sensing platforms, including optical, conductometric and acoustic resonators. After explaining the principle of electrospinning, we classify sensors based on the type of materials used as an active sensing layer, including polymers, metal oxide semiconductors, graphene, and their composites or their functionalized forms. The material properties of these electrospun fibers and their sensing performance toward different analytes are explained in detail and correlated to the benefits and limitations for every approach.
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Affiliation(s)
- Muhammad Imran
- Institute for Future Environments and School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology (QUT), Brisbane, QLD 4001, Australia
| | - Nunzio Motta
- Institute for Future Environments and School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology (QUT), Brisbane, QLD 4001, Australia
| | - Mahnaz Shafiei
- Institute for Future Environments and School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology (QUT), Brisbane, QLD 4001, Australia
- Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, VIC 3122, Australia
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17
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Fusco Z, Rahmani M, Bo R, Verre R, Motta N, Käll M, Neshev D, Tricoli A. Nanostructured Dielectric Fractals on Resonant Plasmonic Metasurfaces for Selective and Sensitive Optical Sensing of Volatile Compounds. Adv Mater 2018; 30:e1800931. [PMID: 29862583 DOI: 10.1002/adma.201800931] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 04/01/2018] [Indexed: 06/08/2023]
Abstract
Advances in the understanding and fabrication of plasmonic nanostructures have led to a plethora of unprecedented optoelectronic and optochemical applications. Plasmon resonance has found widespread use in efficient optical transducers of refractive index changes in liquids. However, it has proven challenging to translate these achievements to the selective detection of gases, which typically adsorb non-specifically and induce refractive index changes below the detection limit. Here, it's shown that integration of tailored fractals of dielectric TiO2 nanoparticles on a plasmonic metasurface strongly enhances the interaction between the plasmonic field and volatile organic molecules and provides a means for their selective detection. Notably, this superior optical response is due to the enhancement of the interaction between the dielectric fractals and the plasmonic metasurface for thickness of up to 1.8 μm, much higher than the evanescent plasmonic near-field (≈30 nm) . Optimal dielectric-plasmonic structures allow measurements of changes in the refractive index of the gas mixture down to <8 × 10-6 at room temperature and selective identification of three exemplary volatile organic compounds. These findings provide a basis for the development of a novel family of dielectric-plasmonic materials with application extending from light harvesting and photocatalysts to contactless sensors for noninvasive medical diagnostics.
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Affiliation(s)
- Zelio Fusco
- Nanotechnology Research Laboratory, College of Engineering and Computer Science, The Australian National University, ACT, 2601, Australia
| | - Mohsen Rahmani
- Nonlinear Physics Centre, Research School of Physics and Engineering, The Australian National University, ACT, 2601, Australia
| | - Renheng Bo
- Nanotechnology Research Laboratory, College of Engineering and Computer Science, The Australian National University, ACT, 2601, Australia
| | - Ruggero Verre
- Department of Physics, Chalmers University of Technology, 412 96, Göteborg, Sweden
| | - Nunzio Motta
- Institute for Future Environments and School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD, 4001, Australia
| | - Mikael Käll
- Department of Physics, Chalmers University of Technology, 412 96, Göteborg, Sweden
| | - Dragomir Neshev
- Nonlinear Physics Centre, Research School of Physics and Engineering, The Australian National University, ACT, 2601, Australia
| | - Antonio Tricoli
- Nanotechnology Research Laboratory, College of Engineering and Computer Science, The Australian National University, ACT, 2601, Australia
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18
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Morawska L, Thai PK, Liu X, Asumadu-Sakyi A, Ayoko G, Bartonova A, Bedini A, Chai F, Christensen B, Dunbabin M, Gao J, Hagler GSW, Jayaratne R, Kumar P, Lau AKH, Louie PKK, Mazaheri M, Ning Z, Motta N, Mullins B, Rahman MM, Ristovski Z, Shafiei M, Tjondronegoro D, Westerdahl D, Williams R. Applications of low-cost sensing technologies for air quality monitoring and exposure assessment: How far have they gone? Environ Int 2018; 116:286-299. [PMID: 29704807 PMCID: PMC6145068 DOI: 10.1016/j.envint.2018.04.018] [Citation(s) in RCA: 210] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 04/11/2018] [Accepted: 04/11/2018] [Indexed: 05/19/2023]
Abstract
Over the past decade, a range of sensor technologies became available on the market, enabling a revolutionary shift in air pollution monitoring and assessment. With their cost of up to three orders of magnitude lower than standard/reference instruments, many avenues for applications have opened up. In particular, broader participation in air quality discussion and utilisation of information on air pollution by communities has become possible. However, many questions have been also asked about the actual benefits of these technologies. To address this issue, we conducted a comprehensive literature search including both the scientific and grey literature. We focused upon two questions: (1) Are these technologies fit for the various purposes envisaged? and (2) How far have these technologies and their applications progressed to provide answers and solutions? Regarding the former, we concluded that there is no clear answer to the question, due to a lack of: sensor/monitor manufacturers' quantitative specifications of performance, consensus regarding recommended end-use and associated minimal performance targets of these technologies, and the ability of the prospective users to formulate the requirements for their applications, or conditions of the intended use. Numerous studies have assessed and reported sensor/monitor performance under a range of specific conditions, and in many cases the performance was concluded to be satisfactory. The specific use cases for sensors/monitors included outdoor in a stationary mode, outdoor in a mobile mode, indoor environments and personal monitoring. Under certain conditions of application, project goals, and monitoring environments, some sensors/monitors were fit for a specific purpose. Based on analysis of 17 large projects, which reached applied outcome stage, and typically conducted by consortia of organizations, we observed that a sizable fraction of them (~ 30%) were commercial and/or crowd-funded. This fact by itself signals a paradigm change in air quality monitoring, which previously had been primarily implemented by government organizations. An additional paradigm-shift indicator is the growing use of machine learning or other advanced data processing approaches to improve sensor/monitor agreement with reference monitors. There is still some way to go in enhancing application of the technologies for source apportionment, which is of particular necessity and urgency in developing countries. Also, there has been somewhat less progress in wide-scale monitoring of personal exposures. However, it can be argued that with a significant future expansion of monitoring networks, including indoor environments, there may be less need for wearable or portable sensors/monitors to assess personal exposure. Traditional personal monitoring would still be valuable where spatial variability of pollutants of interest is at a finer resolution than the monitoring network can resolve.
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Affiliation(s)
- Lidia Morawska
- Queensland University of Technology, International Laboratory for Air Quality & Health, Brisbane, QLD, Australia; Queensland University of Technology, Science and Engineering Faculty, Brisbane, QLD, Australia.
| | - Phong K Thai
- Queensland University of Technology, International Laboratory for Air Quality & Health, Brisbane, QLD, Australia; Queensland University of Technology, Science and Engineering Faculty, Brisbane, QLD, Australia
| | - Xiaoting Liu
- Queensland University of Technology, International Laboratory for Air Quality & Health, Brisbane, QLD, Australia; Queensland University of Technology, Science and Engineering Faculty, Brisbane, QLD, Australia
| | - Akwasi Asumadu-Sakyi
- Queensland University of Technology, International Laboratory for Air Quality & Health, Brisbane, QLD, Australia; Queensland University of Technology, Science and Engineering Faculty, Brisbane, QLD, Australia
| | - Godwin Ayoko
- Queensland University of Technology, International Laboratory for Air Quality & Health, Brisbane, QLD, Australia; Queensland University of Technology, Science and Engineering Faculty, Brisbane, QLD, Australia
| | - Alena Bartonova
- Norwegian Institute for Air Research, POB 100, N-2027 Kjeller, Norway
| | | | - Fahe Chai
- Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Bryce Christensen
- Queensland University of Technology, International Laboratory for Air Quality & Health, Brisbane, QLD, Australia; Queensland University of Technology, Science and Engineering Faculty, Brisbane, QLD, Australia
| | - Matthew Dunbabin
- Queensland University of Technology, Institute for Future Environments, Brisbane, QLD, Australia
| | - Jian Gao
- Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Gayle S W Hagler
- U.S. Environmental Protection Agency, Office of Research and Development, Research Triangle Park, NC, USA
| | - Rohan Jayaratne
- Queensland University of Technology, International Laboratory for Air Quality & Health, Brisbane, QLD, Australia; Queensland University of Technology, Science and Engineering Faculty, Brisbane, QLD, Australia
| | - Prashant Kumar
- Global Centre for Clean Air Research (GCARE), Department of Civil and Environmental Engineering, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, GU2 7XH, Surrey, United Kingdom
| | - Alexis K H Lau
- Hong Kong University of Science and Technology, Hong Kong, China
| | - Peter K K Louie
- Environmental Protection Department, Government of the Hong Kong Special Administration Region, China
| | - Mandana Mazaheri
- Queensland University of Technology, International Laboratory for Air Quality & Health, Brisbane, QLD, Australia; Queensland University of Technology, Science and Engineering Faculty, Brisbane, QLD, Australia; Climate and Atmospheric Science Branch, NSW Office of Environment and Heritage, Sydney, NSW, Australia
| | - Zhi Ning
- School of Energy and Environment, City University of Hong Kong, Hong Kong, China
| | - Nunzio Motta
- Queensland University of Technology, Science and Engineering Faculty, Brisbane, QLD, Australia
| | - Ben Mullins
- Curtin Institute for Computation, Occupation and Environment, School of Public Health, Curtin University, Perth, WA, Australia
| | - Md Mahmudur Rahman
- Queensland University of Technology, International Laboratory for Air Quality & Health, Brisbane, QLD, Australia; Queensland University of Technology, Science and Engineering Faculty, Brisbane, QLD, Australia
| | - Zoran Ristovski
- Queensland University of Technology, International Laboratory for Air Quality & Health, Brisbane, QLD, Australia; Queensland University of Technology, Science and Engineering Faculty, Brisbane, QLD, Australia
| | - Mahnaz Shafiei
- Queensland University of Technology, Science and Engineering Faculty, Brisbane, QLD, Australia; Queensland University of Technology, Institute for Future Environments, Brisbane, QLD, Australia; Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, VIC 3122, Australia
| | - Dian Tjondronegoro
- School of Business and Tourism, Southern Cross University, QLD, Australia
| | - Dane Westerdahl
- School of Energy and Environment, City University of Hong Kong, Hong Kong, China
| | - Ron Williams
- U.S. Environmental Protection Agency, Office of Research and Development, Research Triangle Park, NC, USA
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Di Bernardo I, Hines P, Abyazisani M, Motta N, MacLeod J, Lipton-Duffin J. On-surface synthesis of polyethylenedioxythiophene. Chem Commun (Camb) 2018; 54:3723-3726. [PMID: 29589016 DOI: 10.1039/c8cc01465e] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
On-surface synthesis of conjugated polymers is made challenging by the need to promote the desired reaction while preventing or minimizing unwanted ancillary reactions that compromise the product integrity. We perform a comprehensive study of the reactions of 2,5-dichloro-3,4-ethylenedioxythiophene on coinage metal surfaces, and demonstrate that only on Ag(111) can we obtain a planar polymer product, polyethylenedioxythiophene (PEDOT).
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20
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Amjadipour M, Tadich A, Boeckl JJ, Lipton-Duffin J, MacLeod J, Iacopi F, Motta N. Quasi free-standing epitaxial graphene fabrication on 3C-SiC/Si(111). Nanotechnology 2018; 29:145601. [PMID: 29376834 DOI: 10.1088/1361-6528/aaab1a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Growing graphene on SiC thin films on Si is a cheaper alternative to the growth on bulk SiC, and for this reason it has been recently intensively investigated. Here we study the effect of hydrogen intercalation on epitaxial graphene obtained by high temperature annealing on 3C-SiC/Si(111) in ultra-high vacuum. By using a combination of core-level photoelectron spectroscopy, low energy electron diffraction, and near-edge x-ray absorption fine structure (NEXAFS) we find that hydrogen saturates the Si atoms at the topmost layer of the substrate, leading to free-standing graphene on 3C-SiC/Si(111). The intercalated hydrogen fully desorbs after heating the sample at 850 °C and the buffer layer appears again, similar to what has been reported for bulk SiC. However, the NEXAFS analysis sheds new light on the effect of hydrogen intercalation, showing an improvement of graphene's flatness after annealing in atomic H at 600 °C. These results provide new insight into free-standing graphene fabrication on SiC/Si thin films.
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Affiliation(s)
- Mojtaba Amjadipour
- School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty, Queensland University of Technology, QLD, Australia
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21
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Rigoni F, Maiti R, Baratto C, Donarelli M, MacLeod J, Gupta B, Lyu M, Ponzoni A, Sberveglieri G, Motta N, Faglia G. Transfer of CVD-grown graphene for room temperature gas sensors. Nanotechnology 2017; 28:414001. [PMID: 28805655 DOI: 10.1088/1361-6528/aa8611] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
An easy transfer procedure to obtain graphene-based gas sensing devices operating at room temperature (RT) is presented. Starting from chemical vapor deposition-grown graphene on copper foil, we obtained single layer graphene which could be transferred onto arbitrary substrates. In particular, we placed single layer graphene on top of a SiO2/Si substrate with pre-patterned Pt electrodes to realize a chemiresistor gas sensor able to operate at RT. The responses to ammonia (10, 20, 30 ppm) and nitrogen dioxide (1, 2, 3 ppm) are shown at different values of relative humidity, in dark and under 254 nm UV light. In order to check the sensor selectivity, gas response has also been tested towards hydrogen, ethanol, acetone and carbon oxide. Finally, a model based on linear dispersion relation characteristic of graphene, which take into account humidity and UV light effects, has been proposed.
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Affiliation(s)
- F Rigoni
- Sensor Lab, Department of Information Engineering, University of Brescia, Via Branze 38, I-25123 Brescia, Italy. Sensor Lab, CNR-INO Via Branze 45, I-25123 Brescia, Italy
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22
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Amjadipour M, MacLeod J, Lipton-Duffin J, Iacopi F, Motta N. Epitaxial graphene growth on FIB patterned 3C-SiC nanostructures on Si (111): reducing milling damage. Nanotechnology 2017; 28:345602. [PMID: 28548043 DOI: 10.1088/1361-6528/aa752e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Epitaxial growth of graphene on SiC is a scalable procedure that does not require any further transfer step, making this an ideal platform for graphene nanostructure fabrication. Focused ion beam (FIB) is a very promising tool for exploring the reduction of the lateral dimension of graphene on SiC to the nanometre scale. However, exposure of graphene to the Ga+ beam causes significant surface damage through amorphisation and contamination, preventing epitaxial graphene growth. In this paper we demonstrate that combining a protective silicon layer with FIB patterning implemented prior to graphene growth can significantly reduce the damage associated with FIB milling. Using this approach, we successfully achieved graphene growth over 3C-SiC/Si FIB patterned nanostructures.
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Affiliation(s)
- Mojtaba Amjadipour
- School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty, Queensland University of Technology, QLD, Australia
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23
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Di Bernardo I, Avvisati G, Mariani C, Motta N, Chen C, Avila J, Asensio MC, Lupi S, Ito Y, Chen M, Fujita T, Betti MG. Two-Dimensional Hallmark of Highly Interconnected Three-Dimensional Nanoporous Graphene. ACS Omega 2017; 2:3691-3697. [PMID: 31457683 PMCID: PMC6641586 DOI: 10.1021/acsomega.7b00706] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 07/05/2017] [Indexed: 05/24/2023]
Abstract
Scaling graphene from a two-dimensional (2D) ideal structure to a three-dimensional (3D) millimeter-sized architecture without compromising its remarkable electrical, optical, and thermal properties is currently a great challenge to overcome the limitations of integrating single graphene flakes into 3D devices. Herewith, highly connected and continuous nanoporous graphene (NPG) samples, with electronic and vibrational properties very similar to those of suspended graphene layers, are presented. We pinpoint the hallmarks of 2D ideal graphene scaled in these 3D porous architectures by combining the state-of-the-art spectromicroscopy and imaging techniques. The connected and bicontinuous topology, without frayed borders and edges and with low density of crystalline defects, has been unveiled via helium ion, Raman, and transmission electron microscopies down to the atomic scale. Most importantly, nanoscanning photoemission unravels a 3D NPG structure with preserved 2D electronic density of states (Dirac cone like) throughout the porous sample. Furthermore, the high spatial resolution brings to light the interrelationship between the topology and the morphology in the wrinkled and highly bent regions, where distorted sp2 C bonds, associated with sp3-like hybridization state, induce small energy gaps. This highly connected graphene structure with a 3D skeleton overcomes the limitations of small-sized individual graphene sheets and opens a new route for a plethora of applications of the 2D graphene properties in 3D devices.
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Affiliation(s)
- Iolanda Di Bernardo
- Department
of Physics, Sapienza University of Rome, Piazzale Aldo Moro 2, 00185 Rome, Italy
| | - Giulia Avvisati
- Department
of Physics, Sapienza University of Rome, Piazzale Aldo Moro 2, 00185 Rome, Italy
| | - Carlo Mariani
- Department
of Physics, Sapienza University of Rome, Piazzale Aldo Moro 2, 00185 Rome, Italy
| | - Nunzio Motta
- School
of Chemistry, Physics and Mechanical Engineering and Institute for
Future Environments, Queensland University
of Technology, 2 George
Street, 4000 Brisbane, Australia
| | - Chaoyu Chen
- Synchrotron
SOLEIL, L’Orme des Merisiers, Saint Aubin, 91190 Gif sur Yvette, France
| | - José Avila
- Synchrotron
SOLEIL, L’Orme des Merisiers, Saint Aubin, 91190 Gif sur Yvette, France
| | - Maria Carmen Asensio
- Synchrotron
SOLEIL, L’Orme des Merisiers, Saint Aubin, 91190 Gif sur Yvette, France
| | - Stefano Lupi
- Department
of Physics, CNR-IOM, Sapienza University
of Rome, Piazzale Aldo Moro 2, 00185 Rome, Italy
| | - Yoshikazu Ito
- Institute
of Applied Physics, Graduate School of Pure and Applied Sciences, University of Tsukuba, 305-8571 Tsukuba, Japan
- PRESTO,
Japan Science and Technology Agency, 332-0012 Saitama, Japan
| | - Mingwei Chen
- Advanced
Institute for Materials Research, Tohoku University, 980-8577 Sendai, Japan
| | - Takeshi Fujita
- Advanced
Institute for Materials Research, Tohoku University, 980-8577 Sendai, Japan
| | - Maria Grazia Betti
- Department
of Physics, Sapienza University of Rome, Piazzale Aldo Moro 2, 00185 Rome, Italy
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24
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Motta N. Nanostructures for sensors, electronics, energy and environment III. Beilstein J Nanotechnol 2017; 8:1530-1531. [PMID: 28884058 PMCID: PMC5550816 DOI: 10.3762/bjnano.8.154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 06/28/2017] [Indexed: 06/07/2023]
Affiliation(s)
- Nunzio Motta
- School of Chemistry, Physics and Mechanical Engineering and Institute for Future Environments, Queensland University of Technology, 2 George St., Brisbane 4001, Australia
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25
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Zhao Y, Liu J, Wang B, Sha J, Li Y, Zheng D, Amjadipour M, MacLeod J, Motta N. Supercapacitor Electrodes with Remarkable Specific Capacitance Converted from Hybrid Graphene Oxide/NaCl/Urea Films. ACS Appl Mater Interfaces 2017; 9:22588-22596. [PMID: 28609091 DOI: 10.1021/acsami.7b05965] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A novel approach to improve the specific capacitance of reduced graphene oxide (rGO) films is reported. We combine the aqueous dispersion of liquid-crystalline GO incorporating salt and urea with a blade-coating technique to make hybrid films. After drying, stacked GO sheets mediated by solidified NaCl and urea are hydrothermally reduced, resulting in a nanoporous film consisting of rumpled N-doped rGO sheets. As a supercapacitor electrode, the film exhibits a high gravimetric specific capacitance of 425 F g-1 and a record volumetric specific capacitance of 693 F cm-3 at 1 A g-1 in 1 M H2SO4 aqueous electrolyte when integrated into a symmetric cell. When using Li2SO4 aqueous electrolyte, which can extend the potential window to 1.6 V, the device exhibits high energy densities up to 35 Wh kg-1, and high power densities up to 104 W kg-1. This novel strategy to intercalate solidified chemicals into stacked GO sheets to functionalize them and prevent them from restacking provides a promising route toward supercapacitors with high specific capacitance and energy density.
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Affiliation(s)
- Yi Zhao
- School of Materials Science and Engineering, Beihang University , Beijing 100191, China
| | - Jinzhang Liu
- School of Materials Science and Engineering, Beihang University , Beijing 100191, China
| | - Bin Wang
- School of Materials Science and Engineering, Beihang University , Beijing 100191, China
| | - Jiangbo Sha
- School of Materials Science and Engineering, Beihang University , Beijing 100191, China
| | - Yan Li
- School of Materials Science and Engineering, Beihang University , Beijing 100191, China
| | - Dezhi Zheng
- School of Instrumentation Science and Optoelectronics Engineering, Beihang University , Beijing 100191, China
| | - Mojtaba Amjadipour
- School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology , Brisbane 4001, QLD, Australia
| | - Jennifer MacLeod
- School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology , Brisbane 4001, QLD, Australia
| | - Nunzio Motta
- School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology , Brisbane 4001, QLD, Australia
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26
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Mondelli P, Gupta B, Betti MG, Mariani C, Duffin JL, Motta N. High quality epitaxial graphene by hydrogen-etching of 3C-SiC(111) thin-film on Si(111). Nanotechnology 2017; 28:115601. [PMID: 28099157 DOI: 10.1088/1361-6528/aa5a48] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Etching with atomic hydrogen, as a preparation step before the high-temperature growth process of graphene onto a thin 3C-SiC film grown on Si(111), greatly improves the structural quality of topmost graphene layers. Pit formation and island coalescence, which are typical of graphene growth by SiC graphitization, are quenched and accompanied by widening of the graphene domain sizes to hundreds of nanometers, and by a significant reduction in surface roughness down to a single substrate bilayer. The surface reconstructions expected for graphene and the underlying layer are shown with atomic resolution by scanning tunnelling microscopy. Spectroscopic features typical of graphene are measured by core-level photoemission and Raman spectroscopy.
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Affiliation(s)
- Pierluigi Mondelli
- Dipartimento di Fisica, Università di Roma 'La Sapienza', Piazzale Aldo Moro 2, I-00185 Roma, Italy. School of Chemistry Physics and Mechanical Engineering and Institute for Future Environments, Queensland University of Technology, 2 George Street, Brisbane 4001, QLD, Australia
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27
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Wang B, Liu J, Zhao Y, Li Y, Xian W, Amjadipour M, MacLeod J, Motta N. Role of Graphene Oxide Liquid Crystals in Hydrothermal Reduction and Supercapacitor Performance. ACS Appl Mater Interfaces 2016; 8:22316-22323. [PMID: 27529434 DOI: 10.1021/acsami.6b05779] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The formation of liquid crystal (LC) phases in graphene oxide (GO) aqueous solution is utilized to develop high-performance supercapacitors. To investigate the effect of LC formation on the properties of subsequently reduced GO (rGO), we compare films prepared through blade-coating of viscous LC-GO solution and ultrasonic spray-coating of diluted GO aqueous dispersion. After hydrothermal reduction under identical conditions, the films show different morphology, oxygen content, and specific capacitance. Trapped water in the LC GO film plays a role in preventing restacking of sheets and facilitating the removal of oxygenated groups during the reduction process. In device architectures with either liquid or polymer electrolyte, the specific capacitance of the blade-coated film is twice as high as that of the spray-coated one. For a blade-coated film with mass loading of 0.115 mg/cm(2), the specific capacitance reaches 286 F/g in aqueous electrolyte and 263 F/g in gelled electrolyte, respectively. This study suggests a route to pilot-scale production of high-performance graphene supercapacitors through blade-coated LC-GO films.
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Affiliation(s)
- Bin Wang
- School of Materials Science and Engineering, Beihang University , Beijing 100191, China
| | - Jinzhang Liu
- School of Materials Science and Engineering, Beihang University , Beijing 100191, China
| | - Yi Zhao
- School of Materials Science and Engineering, Beihang University , Beijing 100191, China
| | - Yan Li
- School of Materials Science and Engineering, Beihang University , Beijing 100191, China
| | - Wei Xian
- Siansonic Technology Co. Ltd. , Beijing 101111, China
| | - Mojtaba Amjadipour
- School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology , Brisbane 4001, QLD, Australia
| | - Jennifer MacLeod
- School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology , Brisbane 4001, QLD, Australia
| | - Nunzio Motta
- School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology , Brisbane 4001, QLD, Australia
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28
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Datta AJ, Gupta B, Shafiei M, Taylor R, Motta N. Growth of graphene on cylindrical copper conductors as an anticorrosion coating: a microscopic study. Nanotechnology 2016; 27:285704. [PMID: 27263663 DOI: 10.1088/0957-4484/27/28/285704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We have successfully grown graphene film on the surface of cylindrical copper conductors by chemical vapour deposition. The quality and number of graphene layers have been investigated using Raman spectroscopy, Raman mapping and scanning electron microscopy, as a function of methane gas flow rate and of growth temperature. Transmission electron microscopy analysis has been performed to verify the number of graphene layers, confirming the results obtained by Raman spectroscopy. The results open up the possibility of using graphene as an anticorrosion coating for copper cables and earth grids.
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Affiliation(s)
- A J Datta
- Electrical Engineering and Computer Science School, Queensland University of Technology (QUT), Brisbane 4001, QLD, Australia
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29
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Gupta B, Di Bernardo I, Mondelli P, Della Pia A, Betti MG, Iacopi F, Mariani C, Motta N. Effect of substrate polishing on the growth of graphene on 3C-SiC(111)/Si(111) by high temperature annealing. Nanotechnology 2016; 27:185601. [PMID: 26999014 DOI: 10.1088/0957-4484/27/18/185601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We analyse the effects of substrate polishing and of the epilayer thickness on the quality of graphene layers grown by high temperature annealing on 3C-SiC(111)/Si(111) by scanning tunnelling microscopy, x-ray photoelectron spectroscopy, Raman spectroscopy, low energy electron diffraction and high resolution angle resolved photoemission spectroscopy. The results provide a comprehensive set of data confirming the superior quality of the graphene layers obtained on polished substrates, and the limitations of the growth obtained on unpolished surfaces.
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Affiliation(s)
- B Gupta
- School of Chemistry, Physics and Mechanical Engineering and Institute for Future Environments, Queensland University of Technology, 2 George Street, Brisbane 4001, QLD, Australia
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30
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Wang B, Liu J, Mirri F, Pasquali M, Motta N, Holmes JW. High-performance graphene-based supercapacitors made by a scalable blade-coating approach. Nanotechnology 2016; 27:165402. [PMID: 26953864 DOI: 10.1088/0957-4484/27/16/165402] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Graphene oxide (GO) sheets can form liquid crystals (LCs) in their aqueous dispersions that are more viscous with a stronger LC feature. In this work we combine the viscous LC-GO solution with the blade-coating technique to make GO films, for constructing graphene-based supercapacitors in a scalable way. Reduced GO (rGO) films are prepared by wet chemical methods, using either hydrazine (HZ) or hydroiodic acid (HI). Solid-state supercapacitors with rGO films as electrodes and highly conductive carbon nanotube films as current collectors are fabricated and the capacitive properties of different rGO films are compared. It is found that the HZ-rGO film is superior to the HI-rGO film in achieving high capacitance, owing to the 3D structure of graphene sheets in the electrode. Compared to gelled electrolyte, the use of liquid electrolyte (H2SO4) can further increase the capacitance to 265 F per gram (corresponding to 52 mF per cm(2)) of the HZ-rGO film.
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Affiliation(s)
- Bin Wang
- School of Materials Science and Engineering, Beihang University, Beijing, People's Republic of China
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31
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Silva M, Marta G, Lisboa F, Watte G, Trippa F, Maranzano E, Motta N, Chow E. EP-1423: Hypofractionated radiotherapy for complicated bone metastases in patients with poor performance. Radiother Oncol 2016. [DOI: 10.1016/s0167-8140(16)32673-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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32
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Notarianni M, Liu J, Vernon K, Motta N. Synthesis and applications of carbon nanomaterials for energy generation and storage. Beilstein J Nanotechnol 2016; 7:149-196. [PMID: 26925363 PMCID: PMC4734431 DOI: 10.3762/bjnano.7.17] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 12/22/2015] [Indexed: 05/29/2023]
Abstract
The world is facing an energy crisis due to exponential population growth and limited availability of fossil fuels. Over the last 20 years, carbon, one of the most abundant materials found on earth, and its allotrope forms such as fullerenes, carbon nanotubes and graphene have been proposed as sources of energy generation and storage because of their extraordinary properties and ease of production. Various approaches for the synthesis and incorporation of carbon nanomaterials in organic photovoltaics and supercapacitors have been reviewed and discussed in this work, highlighting their benefits as compared to other materials commonly used in these devices. The use of fullerenes, carbon nanotubes and graphene in organic photovoltaics and supercapacitors is described in detail, explaining how their remarkable properties can enhance the efficiency of solar cells and energy storage in supercapacitors. Fullerenes, carbon nanotubes and graphene have all been included in solar cells with interesting results, although a number of problems are still to be overcome in order to achieve high efficiency and stability. However, the flexibility and the low cost of these materials provide the opportunity for many applications such as wearable and disposable electronics or mobile charging. The application of carbon nanotubes and graphene to supercapacitors is also discussed and reviewed in this work. Carbon nanotubes, in combination with graphene, can create a more porous film with extraordinary capacitive performance, paving the way to many practical applications from mobile phones to electric cars. In conclusion, we show that carbon nanomaterials, developed by inexpensive synthesis and process methods such as printing and roll-to-roll techniques, are ideal for the development of flexible devices for energy generation and storage - the key to the portable electronics of the future.
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Affiliation(s)
- Marco Notarianni
- Institute of Future Environments and School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane QLD 4001, Australia
- Plasma-Therm LLC, 10050 16th St. North, St. Petersburg, FL 33716, USA
| | - Jinzhang Liu
- School of Materials Science and Engineering, Beihang University, Beijing 100191, China
| | - Kristy Vernon
- Institute of Future Environments and School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane QLD 4001, Australia
| | - Nunzio Motta
- Institute of Future Environments and School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane QLD 4001, Australia
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33
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Ahmed M, Khawaja M, Notarianni M, Wang B, Goding D, Gupta B, Boeckl JJ, Takshi A, Motta N, Saddow SE, Iacopi F. A thin film approach for SiC-derived graphene as an on-chip electrode for supercapacitors. Nanotechnology 2015; 26:434005. [PMID: 26447742 DOI: 10.1088/0957-4484/26/43/434005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We designed a nickel-assisted process to obtain graphene with sheet resistance as low as 80 Ω square(-1) from silicon carbide films on Si wafers with highly enhanced surface area. The silicon carbide film acts as both a template and source of graphitic carbon, while, simultaneously, the nickel induces porosity on the surface of the film by forming silicides during the annealing process which are subsequently removed. As stand-alone electrodes in supercapacitors, these transfer-free graphene-on-chip samples show a typical double-layer supercapacitive behaviour with gravimetric capacitance of up to 65 F g(-1). This work is the first attempt to produce graphene with high surface area from silicon carbide thin films for energy storage at the wafer-level and may open numerous opportunities for on-chip integrated energy storage applications.
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Affiliation(s)
- Mohsin Ahmed
- Queensland Micro- and Nanotechnology Centre, Griffith University, Nathan, QLD, Australia
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34
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Motta N. Nanostructures for sensors, electronics, energy and environment II. Beilstein J Nanotechnol 2015; 6:1937-1938. [PMID: 26665064 PMCID: PMC4660910 DOI: 10.3762/bjnano.6.197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 09/12/2015] [Indexed: 06/05/2023]
Affiliation(s)
- Nunzio Motta
- School of Chemistry, Physics and Mechanical Engineering and Institute for Future Environments, Queensland University of Technology, 2 George St., Brisbane 4001, Australia
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35
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Abstract
Flexible and solid-state supercapacitors are made using compressed graphene foams as electrodes and highly conductive carbon nanotube (CNT) films as current collectors.
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Affiliation(s)
- Jinzhang Liu
- School of Materials Science and Engineering
- International Research Institute for Multidisciplinary Science
- Beihang University
- Beijing
- China
| | - Bin Wang
- School of Materials Science and Engineering
- International Research Institute for Multidisciplinary Science
- Beihang University
- Beijing
- China
| | - Francesca Mirri
- Department of Chemical and Biomolecular Engineering
- The Smalley Institute for Nanoscience and Technology
- Rice University
- Houston
- USA
| | - Matteo Pasquali
- Department of Chemical and Biomolecular Engineering
- The Smalley Institute for Nanoscience and Technology
- Rice University
- Houston
- USA
| | - Nunzio Motta
- School of Chemistry, Physics, and Mechanical Engineering
- Queensland University of Technology
- Brisbane
- Australia
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36
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Affiliation(s)
- Marco Notarianni
- Institute of Future Environments and School of Chemistry Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane QLD 4001, Australia
| | - Kristy Vernon
- Institute of Future Environments and School of Chemistry Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane QLD 4001, Australia
| | - Alison Chou
- Institute of Future Environments and School of Chemistry Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane QLD 4001, Australia
| | - Jinzhang Liu
- Institute of Future Environments and School of Chemistry Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane QLD 4001, Australia
| | - Nunzio Motta
- Institute of Future Environments and School of Chemistry Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane QLD 4001, Australia
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37
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Notarianni M, Liu J, Mirri F, Pasquali M, Motta N. Graphene-based supercapacitor with carbon nanotube film as highly efficient current collector. Nanotechnology 2014; 25:435405. [PMID: 25301789 DOI: 10.1088/0957-4484/25/43/435405] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Flexible graphene-based thin film supercapacitors were made using carbon nanotube (CNT) films as current collectors and graphene films as electrodes. The graphene sheets were produced by simple electrochemical exfoliation, while the graphene films with controlled thickness were prepared by vacuum filtration. The solid-state supercapacitor was made by using two graphene/CNT films on plastic substrates to sandwich a thin layer of gelled electrolyte. We found that the thin graphene film with thickness <1 μm can greatly increase the capacitance. Using only CNT films as electrodes, the device exhibited a capacitance as low as ∼0.4 mF cm(-2), whereas by adding a 360 nm thick graphene film to the CNT electrodes led to a ∼4.3 mF cm(-2) capacitance. We experimentally demonstrated that the conductive CNT film is equivalent to gold as a current collector while it provides a stronger binding force to the graphene film. Combining the high capacitance of the thin graphene film and the high conductivity of the CNT film, our devices exhibited high energy density (8-14 Wh kg(-1)) and power density (250-450 kW kg(-1)).
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Affiliation(s)
- Marco Notarianni
- Institute for Future Environments and School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane, 4001 QLD, Australia
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38
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Piloto C, Notarianni M, Shafiei M, Taran E, Galpaya D, Yan C, Motta N. Highly NO2 sensitive caesium doped graphene oxide conductometric sensors. Beilstein J Nanotechnol 2014; 5:1073-1081. [PMID: 25161842 PMCID: PMC4143126 DOI: 10.3762/bjnano.5.120] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Accepted: 06/24/2014] [Indexed: 05/29/2023]
Abstract
Here we report on the synthesis of caesium doped graphene oxide (GO-Cs) and its application to the development of a novel NO2 gas sensor. The GO, synthesized by oxidation of graphite through chemical treatment, was doped with Cs by thermal solid-state reaction. The samples, dispersed in DI water by sonication, have been drop-casted on standard interdigitated Pt electrodes. The response of both pristine and Cs doped GO to NO2 at room temperature is studied by varying the gas concentration. The developed GO-Cs sensor shows a higher response to NO2 than the pristine GO based sensor due to the oxygen functional groups. The detection limit measured with GO-Cs sensor is ≈90 ppb.
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Affiliation(s)
- Carlo Piloto
- Institute for Future Environments and School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD 4001, Australia
| | - Marco Notarianni
- Institute for Future Environments and School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD 4001, Australia
| | - Mahnaz Shafiei
- Institute for Future Environments and School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD 4001, Australia
| | - Elena Taran
- The University of Queensland, Australian Institute for Bioengineering and Nanotechnology, Australian National Fabrication Facility - QLD Node, Brisbane, QLD 4072, Australia
| | - Dilini Galpaya
- Institute for Future Environments and School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD 4001, Australia
| | - Cheng Yan
- Institute for Future Environments and School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD 4001, Australia
| | - Nunzio Motta
- Institute for Future Environments and School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD 4001, Australia
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39
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Persichetti L, Sgarlata A, Mori S, Notarianni M, Cherubini V, Fanfoni M, Motta N, Balzarotti A. Beneficial defects: exploiting the intrinsic polishing-induced wafer roughness for the catalyst-free growth of Ge in-plane nanowires. Nanoscale Res Lett 2014; 9:358. [PMID: 25114649 PMCID: PMC4119939 DOI: 10.1186/1556-276x-9-358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 07/09/2014] [Indexed: 06/03/2023]
Abstract
UNLABELLED We outline a metal-free fabrication route of in-plane Ge nanowires on Ge(001) substrates. By positively exploiting the polishing-induced defects of standard-quality commercial Ge(001) wafers, micrometer-length wires are grown by physical vapor deposition in ultra-high-vacuum environment. The shape of the wires can be tailored by the epitaxial strain induced by subsequent Si deposition, determining a progressive transformation of the wires in SiGe faceted quantum dots. This shape transition is described by finite element simulations of continuous elasticity and gives hints on the equilibrium shape of nanocrystals in the presence of tensile epitaxial strain. PACS 81.07.Gf; 68.35.bg; 68.35.bj; 62.23.Eg.
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Affiliation(s)
- Luca Persichetti
- Department of Materials, ETH Zurich, Hönggerbergring 64, Zürich 8093, Switzerland
| | - Anna Sgarlata
- Dipartimento di Fisica, Università di Roma ‘Tor Vergata’, Via della Ricerca Scientifica 1, Rome 0133, Italy
| | - Stefano Mori
- Dipartimento di Fisica, Università di Roma ‘Tor Vergata’, Via della Ricerca Scientifica 1, Rome 0133, Italy
- Dipartimento di Ingegneria dell’Impresa, ‘Mario Lucertini’, via del Politecnico 1, Rome 00133, Italy
| | - Marco Notarianni
- Institute for Future Environments and School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane QLD 4001, Australia
| | - Valeria Cherubini
- Dipartimento di Fisica, Università di Roma ‘Tor Vergata’, Via della Ricerca Scientifica 1, Rome 0133, Italy
| | - Massimo Fanfoni
- Dipartimento di Fisica, Università di Roma ‘Tor Vergata’, Via della Ricerca Scientifica 1, Rome 0133, Italy
| | - Nunzio Motta
- Institute for Future Environments and School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane QLD 4001, Australia
| | - Adalberto Balzarotti
- Dipartimento di Fisica, Università di Roma ‘Tor Vergata’, Via della Ricerca Scientifica 1, Rome 0133, Italy
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Liu J, Notarianni M, Rintoul L, Motta N. Encapsulation of nanoparticles into single-crystal ZnO nanorods and microrods. Beilstein J Nanotechnol 2014; 5:485-493. [PMID: 24778975 PMCID: PMC3999869 DOI: 10.3762/bjnano.5.56] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 03/22/2014] [Indexed: 06/03/2023]
Abstract
One-dimensional single crystal incorporating functional nanoparticles of other materials could be an interesting platform for various applications. We studied the encapsulation of nanoparticles into single-crystal ZnO nanorods by exploiting the crystal growth of ZnO in aqueous solution. Two types of nanodiamonds with mean diameters of 10 nm and 40 nm, respectively, and polymer nanobeads with size of 200 nm have been used to study the encapsulation process. It was found that by regrowing these ZnO nanorods with nanoparticles attached to their surfaces, a full encapsulation of nanoparticles into nanorods can be achieved. We demonstrate that our low-temperature aqueous solution growth of ZnO nanorods do not affect or cause degradation of the nanoparticles of either inorganic or organic materials. This new growth method opens the way to a plethora of applications combining the properties of single crystal host and encapsulated nanoparticles. We perform micro-photoluminescence measurement on a single ZnO nanorod containing luminescent nanodiamonds and the spectrum has a different shape from that of naked nanodiamonds, revealing the cavity effect of ZnO nanorod.
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Affiliation(s)
- Jinzhang Liu
- Institute for Future Environments and School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane, 4001, QLD, Australia
| | - Marco Notarianni
- Institute for Future Environments and School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane, 4001, QLD, Australia
| | - Llew Rintoul
- Institute for Future Environments and School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane, 4001, QLD, Australia
| | - Nunzio Motta
- Institute for Future Environments and School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane, 4001, QLD, Australia
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Yu J, Yuan L, Wen H, Shafiei M, Field MR, Liang J, Yang J, Liu ZF, Wlodarski W, Motta N, Li YX, Zhang G, Kalantar-Zadeh K, Lai PT. Hydrothermally formed functional niobium oxide doped tungsten nanorods. Nanotechnology 2013; 24:495501. [PMID: 24231755 DOI: 10.1088/0957-4484/24/49/495501] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Nanorod forms of metal oxides are recognized as one of the most remarkable morphologies. Their structure and functionality have driven important advancements in a vast range of electronic devices and applications. In this work, we postulate a novel concept to explain how numerous localized surface states can be engineered into the bandgap of niobium oxide nanorods using tungsten. We discuss their contributions as local state surface charges for the modulation of a Schottky barrier height, the relative dielectric constant and their respective conduction mechanisms. Their effects on hydrogen gas molecule interaction mechanisms are also examined herein. We synthesized niobium tungsten oxide (Nb17W2O25) nanorods via a hydrothermal growth method and evaluated the Schottky barrier height, ideality factor, dielectric constant and trap energy level from the measured I-V versus temperature characteristics in the presence of air and hydrogen to show the validity of our postulations.
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Affiliation(s)
- Jerry Yu
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR
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Liu J, Notarianni M, Will G, Tiong VT, Wang H, Motta N. Electrochemically exfoliated graphene for electrode films: effect of graphene flake thickness on the sheet resistance and capacitive properties. Langmuir 2013; 29:13307-13314. [PMID: 24089707 DOI: 10.1021/la403159n] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We present an electrochemical exfoliation method to produce controlled thickness graphene flakes by ultrasound assistance. Bilayer graphene flakes are dominant in the final product by using sonication during the electrochemical exfoliation process, while without sonication the product contains a larger percentage of four-layer graphene flakes. Graphene sheets prepared by using the two procedures are processed into films to measure their respective sheet resistance and optical transmittance. Solid-state electrolyte supercapacitors are made using the two types of graphene films. Our study reveals that films with a higher content of multilayer graphene flakes are more conductive, and their resistance is more easily reduced by thermal annealing, making them suitable as transparent conducting films. The film with higher content of bilayer graphene flakes shows instead higher capacitance when used as electrode in a supercapacitor.
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Affiliation(s)
- Jinzhang Liu
- Institute for Future Environments and School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology , Brisbane 4001, QLD Australia
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Capasso A, Salamandra L, Di Carlo A, Bell JM, Motta N. Low-temperature synthesis of carbon nanotubes on indium tin oxide electrodes for organic solar cells. Beilstein J Nanotechnol 2012; 3:524-532. [PMID: 23019547 PMCID: PMC3458597 DOI: 10.3762/bjnano.3.60] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Accepted: 07/03/2012] [Indexed: 06/01/2023]
Abstract
The electrical performance of indium tin oxide (ITO) coated glass was improved by including a controlled layer of carbon nanotubes directly on top of the ITO film. Multiwall carbon nanotubes (MWCNTs) were synthesized by chemical vapor deposition, using ultrathin Fe layers as catalyst. The process parameters (temperature, gas flow and duration) were carefully refined to obtain the appropriate size and density of MWCNTs with a minimum decrease of the light harvesting in the cell. When used as anodes for organic solar cells based on poly(3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM), the MWCNT-enhanced electrodes are found to improve the charge-carrier extraction from the photoactive blend, thanks to the additional percolation paths provided by the CNTs. The work function of as-modified ITO surfaces was measured by the Kelvin probe method to be 4.95 eV, resulting in an improved matching to the highest occupied molecular orbital level of the P3HT. This is in turn expected to increase the hole transport and collection at the anode, contributing to the significant increase of current density and open-circuit voltage observed in test cells created with such MWCNT-enhanced electrodes.
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Affiliation(s)
- Andrea Capasso
- School of Chemistry Physics and Mechanical Engineering, Queensland University of Technology, George St, 4000 Brisbane, Australia
| | - Luigi Salamandra
- CHOSE (Centre for Hybrid and Organic Solar Energy), Department of Electronic Engineering, University of Rome Tor Vergata, Via del Politecnico 1, 00133 Rome, Italy
| | - Aldo Di Carlo
- CHOSE (Centre for Hybrid and Organic Solar Energy), Department of Electronic Engineering, University of Rome Tor Vergata, Via del Politecnico 1, 00133 Rome, Italy
| | - John Marcus Bell
- School of Chemistry Physics and Mechanical Engineering, Queensland University of Technology, George St, 4000 Brisbane, Australia
| | - Nunzio Motta
- School of Chemistry Physics and Mechanical Engineering, Queensland University of Technology, George St, 4000 Brisbane, Australia
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Waclawik ER, Chang J, Ponzoni A, Concina I, Zappa D, Comini E, Motta N, Faglia G, Sberveglieri G. Functionalised zinc oxide nanowire gas sensors: Enhanced NO(2) gas sensor response by chemical modification of nanowire surfaces. Beilstein J Nanotechnol 2012; 3:368-377. [PMID: 23016141 PMCID: PMC3388361 DOI: 10.3762/bjnano.3.43] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Accepted: 03/16/2012] [Indexed: 05/27/2023]
Abstract
Surface coating with an organic self-assembled monolayer (SAM) can enhance surface reactions or the absorption of specific gases and hence improve the response of a metal oxide (MOx) sensor toward particular target gases in the environment. In this study the effect of an adsorbed organic layer on the dynamic response of zinc oxide nanowire gas sensors was investigated. The effect of ZnO surface functionalisation by two different organic molecules, tris(hydroxymethyl)aminomethane (THMA) and dodecanethiol (DT), was studied. The response towards ammonia, nitrous oxide and nitrogen dioxide was investigated for three sensor configurations, namely pure ZnO nanowires, organic-coated ZnO nanowires and ZnO nanowires covered with a sparse layer of organic-coated ZnO nanoparticles. Exposure of the nanowire sensors to the oxidising gas NO(2) produced a significant and reproducible response. ZnO and THMA-coated ZnO nanowire sensors both readily detected NO(2) down to a concentration in the very low ppm range. Notably, the THMA-coated nanowires consistently displayed a small, enhanced response to NO(2) compared to uncoated ZnO nanowire sensors. At the lower concentration levels tested, ZnO nanowire sensors that were coated with THMA-capped ZnO nanoparticles were found to exhibit the greatest enhanced response. ΔR/R was two times greater than that for the as-prepared ZnO nanowire sensors. It is proposed that the ΔR/R enhancement in this case originates from the changes induced in the depletion-layer width of the ZnO nanoparticles that bridge ZnO nanowires resulting from THMA ligand binding to the surface of the particle coating. The heightened response and selectivity to the NO(2) target are positive results arising from the coating of these ZnO nanowire sensors with organic-SAM-functionalised ZnO nanoparticles.
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Affiliation(s)
- Eric R Waclawik
- School of Chemistry, Physics & Mechanical Engineering, Queensland University of Technology, 2 George Street, 4000 Brisbane, Australia
| | - Jin Chang
- School of Chemistry, Physics & Mechanical Engineering, Queensland University of Technology, 2 George Street, 4000 Brisbane, Australia
| | - Andrea Ponzoni
- SENSOR Lab, CNR-IDASC & Brescia University, Chemistry & Physics Department, Via Valotti 9, 25133 Brescia, Italy
| | - Isabella Concina
- SENSOR Lab, CNR-IDASC & Brescia University, Chemistry & Physics Department, Via Valotti 9, 25133 Brescia, Italy
| | - Dario Zappa
- SENSOR Lab, CNR-IDASC & Brescia University, Chemistry & Physics Department, Via Valotti 9, 25133 Brescia, Italy
| | - Elisabetta Comini
- SENSOR Lab, CNR-IDASC & Brescia University, Chemistry & Physics Department, Via Valotti 9, 25133 Brescia, Italy
| | - Nunzio Motta
- School of Chemistry, Physics & Mechanical Engineering, Queensland University of Technology, 2 George Street, 4000 Brisbane, Australia
| | - Guido Faglia
- SENSOR Lab, CNR-IDASC & Brescia University, Chemistry & Physics Department, Via Valotti 9, 25133 Brescia, Italy
| | - Giorgio Sberveglieri
- SENSOR Lab, CNR-IDASC & Brescia University, Chemistry & Physics Department, Via Valotti 9, 25133 Brescia, Italy
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Motta N. Nanostructures for sensors, electronics, energy and environment. Beilstein J Nanotechnol 2012; 3:351-352. [PMID: 23016138 PMCID: PMC3388358 DOI: 10.3762/bjnano.3.40] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Accepted: 04/27/2012] [Indexed: 06/01/2023]
Affiliation(s)
- Nunzio Motta
- School of Chemistry, Physics & Mechanical Engineering, Queensland University of Technology, Brisbane, 4001, Australia
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Galpaya D, Wang M, Liu M, Motta N, Waclawik E, Yan C. Recent Advances in Fabrication and Characterization of Graphene-Polymer Nanocomposites. ACTA ACUST UNITED AC 2012. [DOI: 10.4236/graphene.2012.12005] [Citation(s) in RCA: 183] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Liu J, Motta N, Lee S. Ultraviolet photodetection of flexible ZnO nanowire sheets in polydimethylsiloxane polymer. Beilstein J Nanotechnol 2012; 3:353-9. [PMID: 23016139 PMCID: PMC3388359 DOI: 10.3762/bjnano.3.41] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 03/28/2012] [Indexed: 05/14/2023]
Abstract
ZnO nanowires are normally exposed to an oxygen atmosphere to achieve high performance in UV photodetection. In this work we present results on a UV photodetector fabricated using a flexible ZnO nanowire sheet embedded in polydimethylsiloxane (PDMS), a gas-permeable polymer, showing reproducible UV photoresponse and enhanced photoconduction. PDMS coating results in a reduced response speed compared to that of a ZnO nanowire film in air. The rising speed is slightly reduced, while the decay time is prolonged by about a factor of four. We conclude that oxygen molecules diffusing in PDMS are responsible for the UV photoresponse.
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Affiliation(s)
- Jinzhang Liu
- School of Chemistry, Physics & Mechanical Engineering, Queensland University of Technology, Brisbane, 4001, Australia
| | - Nunzio Motta
- School of Chemistry, Physics & Mechanical Engineering, Queensland University of Technology, Brisbane, 4001, Australia
| | - Soonil Lee
- Division of Energy Systems Research, Ajou University, Suwon, 443-749, Republic of Korea
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Yusuf KQ, Motta N, Pawlak Z, Oloyede A. A microanalytical study of the surfaces of normal, delipidized, and artificially "resurfaced" articular cartilage. Connect Tissue Res 2011; 53:236-45. [PMID: 22141914 DOI: 10.3109/03008207.2011.630764] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The surface amorphous layer of articular cartilage is of primary importance to its load-bearing and lubrication function. This lipid-filled layer is degraded/disrupted or eliminated when cartilage degenerates due to diseases. This article examines further the characteristic of this surface overlay using a combination of microscopy and imaging methods to evaluate the hypothesis that the surface of articular cartilage can be repaired by exposing degraded cartilage to aqueous synthetic lipid mixtures. The preliminary results demonstrate that it is possible to create a new surface layer of phospholipids on the surface of cartilage following artificial lipid removal, but such a layer does not possess enough mechanical strength for physiological function when created with either unsaturated palmitoyl-oleoyl-phosphatidylcholine or saturated dipalmitoyl-phosphatidylcholine component of joint lipid composition alone. We conclude that this may be due to low structural cohesivity, inadequate time of exposure, and the mix/content of lipid in the incubation environment.
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Affiliation(s)
- Kehinde Quasim Yusuf
- School of Engineering Systems, Queensland University of Technology, Brisbane, QLD, Australia
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Goh RGS, Bell JM, Motta N, Waclawik ER. Microscopic and spectroscopic study of self-ordering in poly(3-hexylthiophene)/carbon nanotubes nanocomposites. J Nanosci Nanotechnol 2006; 6:3929-33. [PMID: 17256355 DOI: 10.1166/jnn.2006.678] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Poly(3-hexylthiophene)-single-walled carbon nanotubes (SWNTs) composites were studied using UV-visible absorbance and Raman spectroscopy, scanning tunneling microscopy (STM) and transmission electron microscopy (TEM). Monolayers of regioregular poly(3-hexyl thiophene) (rrP3HT) adsorbed on SWNTs have been imaged using scanning tunneling microscopy (STM) to obtain measurements of the chiral angles at which the thiophene polymer chains wrap around individual carbon nanotubes (41-48 degrees with respect to nanotube axis) and polymer interchain spacings (1.68 angstroms). The rrP3HT interchain distance is greater for rrP3HT monolayers adsorbed onto the curved surfaces of SWNTs than on the flat surfaces of highly ordered pyrolytic graphite samples (1.4 angstroms). UV-vis spectroscopic data provided strong evidence for increased interchain interactions in composites of rrP3HT and SWNTs compared to the pure polymer. The STM local-probe studies of the native polymer and the composites further confirmed that the rrP3HT interacts with carbon nanotubes to produce a highly ordered material at the molecular level.
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Affiliation(s)
- Roland G S Goh
- Centre for Built Environment and Engineering Research, Queensland University of Technology, GPO Box 2434, Brisbane 400, Australia
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Gonzalez-Mujica F, Motta N, Márquez AH, Capote-Zulueta J. Effects of Bauhinia megalandra aqueous leaf extract on intestinal glucose absorption and uptake by enterocyte brush border membrane vesicles. Fitoterapia 2003; 74:84-90. [PMID: 12628399 DOI: 10.1016/s0367-326x(02)00307-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Aqueous extract of Bauhinia megalandra leaves was able to inhibit the intestinal glucose absorption in a concentration-dependent way and additive to phlorizine. Moreover, B. megalandra leaf extract drastically reduced the 14C-glucose uptake by enterocyte brush border membrane vesicles. The B. megalandra leaf extract administrated orally, simultaneously with glucose improved the glucose tolerance with a significant reduction of the 30-min peak. The extract did not have an effect on the glucose tolerance when glucose was administrated subcutaneously.
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Affiliation(s)
- F Gonzalez-Mujica
- Sección de Bioquímica Médica, Instituto de Medicina Experimental, Facultad de Medicina, Universidad Central de Venezuela, Apartado Postal 50587, Sabana Grande, Caracas, Venezuela.
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