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Atia MA, Smejkal P, Gupta V, Haddad PR, Breadmore MC. Chemical vapour deposition in narrow capillaries: Electro-osmotic flow control in capillary electrophoresis. Anal Chim Acta 2023; 1280:341847. [PMID: 37858546 DOI: 10.1016/j.aca.2023.341847] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 09/05/2023] [Accepted: 09/23/2023] [Indexed: 10/21/2023]
Abstract
BACKGROUND In capillary electrophoresis (CE), the inner surface of fused-silica capillaries is commonly covalently modified with liquid silanes to control electroosmotic flow (EOF). This liquid phase deposition (LPD) approach is challenging for long and narrow-diameter capillaries (≥1 m, ≤25 μm ID) inhibiting commercial production. Here, we use chemical vapour deposition (CVD) to covalently modify capillaries with different silanes. Using a home-built CVD device, capillaries were modified with neutral (3-glycidyloxypropyl) trimethoxysilane (GPTMS), the weak base (3-aminopropyl) trimethoxysilane (APTMS), the weak acid 3-mercaptopropyltrimethoxysilane (MPTMS) and the neutral hydrophobic trichloro(1H,1H,2H,2H-perfluorooctyl) silane (PFOCTS). Gas-phase modification of GPTMS with acid and ammonia allowed further modification of the surface prior to molecular layer deposition (MLD) of poly(p-phenylene terephthalamide) (PPTA) using the self-limiting sequential reaction between terephthalaldehyde (TA) and p-phenylenediamine (PD) vapours. RESULTS Capillaries coated with GPTMS by CVD showed a greater reduction in EOF at all pH values than the conventional LPD. APTMS showed a reduction of the EOF at pH 9, with EOF reversal observed below pH 6. MPTMS provided a slightly lower EOF than an unmodified capillary at high pH, and a slightly higher EOF at lower pH. PFOCTS provided the most consistent EOF as a function of pH. The deposition of successive layers of PPTA resulted in increased surface coverage of the polymer and a greater reduction in EOF at pH higher than 5. The stability of a 10 μm ID GPTMS coated capillary was tested at pH 8.8 in a 200 mM CHES/Tris BGE for the separation of inorganic anions. Over 1.5 months of continuous operation (≈4130 runs), the reproducibility of the apparent mobilities for chloride, nitrite, nitrate and sulfate were 2.43%, 2.56%, 2.63% and 3.05%, respectively. The intra-day and inter-day column-to-column reproducibility and batch-to-batch reproducibility for all the coated capillaries ranged between 0.34% and 3.95%. SIGNIFICANCE The study demonstrates the superior performance of CVD coating for suppressing the EOF compared to LPD allowing the easy modification of long lengths of narrow capillary. The variation in silane, and the ability of MLD to modify and control the surface chemistry, provides a simple and facile method for surface modification. The stability of these coatings will allow long-term capillary electrophoresis monitoring of water chemistry, such as for monitoring fertiliser run-off in natural waters.
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Affiliation(s)
- Mostafa A Atia
- Australian Centre for Research on Separation Science (ACROSS), School of Natural Sciences, University of Tasmania, Private Bag 75, Hobart, Tasmania, 7001, Australia; Department of Analytical Chemistry, Faculty of Pharmacy Helwan University, 11795, Cairo, Egypt.
| | - Petr Smejkal
- Australian Centre for Research on Separation Science (ACROSS), School of Natural Sciences, University of Tasmania, Private Bag 75, Hobart, Tasmania, 7001, Australia.
| | - Vipul Gupta
- Australian Centre for Research on Separation Science (ACROSS), School of Natural Sciences, University of Tasmania, Private Bag 75, Hobart, Tasmania, 7001, Australia.
| | - Paul R Haddad
- Australian Centre for Research on Separation Science (ACROSS), School of Natural Sciences, University of Tasmania, Private Bag 75, Hobart, Tasmania, 7001, Australia.
| | - Michael C Breadmore
- Australian Centre for Research on Separation Science (ACROSS), School of Natural Sciences, University of Tasmania, Private Bag 75, Hobart, Tasmania, 7001, Australia.
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Saji VS. 2D hexagonal boron nitride (h-BN) nanosheets in protective coatings: A literature review. Heliyon 2023; 9:e19362. [PMID: 37681159 PMCID: PMC10481311 DOI: 10.1016/j.heliyon.2023.e19362] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 08/18/2023] [Accepted: 08/20/2023] [Indexed: 09/09/2023] Open
Abstract
The layered 2D hexagonal boron nitride (h-BN) nanosheets (BNNSs) have received significant attention as effective fillers for composite protective coatings in anti-corrosion, anti-oxidation and anti-wear applications. Vapour deposited h-BN mono/multilayers are related classes well-recognized as protective thin films and coatings. This review comprehensively accounts for the research and development of BNNSs in protective coatings. Chemical vapour deposited (CVD) BN thin films and exfoliated BNNSs-incorporated composite polymer coatings are primarily discussed. Inorganic and nanocarbon-based composite coatings are also covered. Future research potentials are presented.
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Affiliation(s)
- Viswanathan S. Saji
- Interdisciplinary Research Center for Advanced Materials, King Fahd University of Petroleum & Minerals, Dhahran - 31261, Saudi Arabia
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Mouloua D, Lejeune M, Rajput NS, Kaja K, El Marssi M, El Khakani MA, Jouiad M. One-step chemically vapor deposited hybrid 1T-MoS 2/2H-MoS 2 heterostructures towards methylene blue photodegradation. Ultrason Sonochem 2023; 95:106381. [PMID: 37004414 PMCID: PMC10457596 DOI: 10.1016/j.ultsonch.2023.106381] [Citation(s) in RCA: 2] [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: 01/31/2023] [Revised: 03/11/2023] [Accepted: 03/22/2023] [Indexed: 06/19/2023]
Abstract
The photocatalytic degradation of methylene blue is a straightforward and cost-effective solution for water decontamination. Although many materials have been reported so far for this purpose, the proposed solutions inflicted high fabrication costs and low efficiencies. Here, we report on the synthesis of tetragonal (1T) and hexagonal (2H) mixed molybdenum disulfide (MoS2) heterostructures for an improved photocatalytic degradation efficiency by means of a single-step chemical vapor deposition (CVD) technique. We demonstrate that the 1T-MoS2/2H-MoS2 heterostructures exhibited a narrow bandgap ∼ 1.7 eV, and a very low reflectance (<5%) under visible-light, owing to their particular vertical micro-flower-like structure. We exfoliated the CVD-synthesised 1T-MoS2/2H-MoS2 films to assess their photodegradation properties towards the standard methylene blue dye. Our results showed that the photo-degradation rate-constant of the 1T-MoS2/2H-MoS2 heterostructures is much greater under UV excitation (i.e., 12.5 × 10-3 min-1) than under visible light illumination (i.e., 9.2 × 10-3 min-1). Our findings suggested that the intermixing of the conductive 1T-MoS2 with the semi-conducting 2H-MoS2 phases favors the photogeneration of electron-hole pairs. More importantly, it promotes a higher efficient charge transfer, which accelerates the methylene blue photodegradation process.
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Affiliation(s)
- D Mouloua
- Laboratory of Physics of Condensed Matter, University of Picardie Jules Verne, Scientific Pole, 33 rue Saint-Leu, 80039 Amiens Cedex 1, France; Institut National de la Recherche Scientifique, Centre-Énergie, Matériaux et Télécommunications, 1650, Blvd, Lionel-Boulet, Varennes, QC J3X-1P7, Canada
| | - M Lejeune
- Laboratory of Physics of Condensed Matter, University of Picardie Jules Verne, Scientific Pole, 33 rue Saint-Leu, 80039 Amiens Cedex 1, France
| | - N S Rajput
- Advanced Materials Research Center, Technology Innovation Institute, P.O. Box 9639, Abu Dhabi, United Arab Emirates
| | - K Kaja
- Laboratoire National de métrologie et d'essais (LNE), 29 av. Roger Hennequin, 78197 Trappes, France
| | - M El Marssi
- Laboratory of Physics of Condensed Matter, University of Picardie Jules Verne, Scientific Pole, 33 rue Saint-Leu, 80039 Amiens Cedex 1, France
| | - M A El Khakani
- Institut National de la Recherche Scientifique, Centre-Énergie, Matériaux et Télécommunications, 1650, Blvd, Lionel-Boulet, Varennes, QC J3X-1P7, Canada.
| | - M Jouiad
- Laboratory of Physics of Condensed Matter, University of Picardie Jules Verne, Scientific Pole, 33 rue Saint-Leu, 80039 Amiens Cedex 1, France.
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Wen B, Yang G, Zhou X, Ding S. Intelligent diffusion regulation induced in-situ growth of cobalt nanoclusters on carbon nanotubes for excellent electromagnetic wave absorption. J Colloid Interface Sci 2023; 634:74-85. [PMID: 36535171 DOI: 10.1016/j.jcis.2022.12.060] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/26/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022]
Abstract
To achieve strong electromagnetic wave absorption performance at thin thicknesses, a chemical vapor deposition approach was employed to prepare Co nanoclusters modified carbon nanotubes. The main mechanism lies in the formation of dispersed oxides on the basis of low melting point and decomposition temperature of cobalt nitrate hexahydrate, while solid oxides are not easy to agglomerate during reduction due to their poor diffusion properties. Additionally, the abundant nitrogen-doped on carbon nanotubes provides abundant metal deposition sites, which further inhibits metal agglomeration. As expected, the reflection loss was robust at -59.96 dB with a low filler loading of 10 wt%, and the bandwidth was broad at 5.4GHz. Several factors contribute to excellent electromagnetic wave absorption, such as multiple reflections and scattering in the internal space, dipole polarization loss induced by plenty of functional groups, and interfacial polarization loss at the interfaces between Co nanoclusters and carbon nanotubes.
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Affiliation(s)
- Bo Wen
- School of Chemistry, Engineering Research Center of Energy Storage Materials and Devices, Ministry of Education, "Four Joint Subjects One Union" School-Enterprise Joint Research Center for Power Battery Recycling & Circulation Utilization Technology, Xi'an Jiaotong University, Xi'an 710049, China
| | - Guorui Yang
- School of Chemistry, Engineering Research Center of Energy Storage Materials and Devices, Ministry of Education, "Four Joint Subjects One Union" School-Enterprise Joint Research Center for Power Battery Recycling & Circulation Utilization Technology, Xi'an Jiaotong University, Xi'an 710049, China.
| | - Xinyu Zhou
- School of Chemistry, Engineering Research Center of Energy Storage Materials and Devices, Ministry of Education, "Four Joint Subjects One Union" School-Enterprise Joint Research Center for Power Battery Recycling & Circulation Utilization Technology, Xi'an Jiaotong University, Xi'an 710049, China
| | - Shujiang Ding
- School of Chemistry, Engineering Research Center of Energy Storage Materials and Devices, Ministry of Education, "Four Joint Subjects One Union" School-Enterprise Joint Research Center for Power Battery Recycling & Circulation Utilization Technology, Xi'an Jiaotong University, Xi'an 710049, China.
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Shah K, Patel S, Halder P, Kundu S, Marzbali MH, Hakeem IG, Pramanik BK, Chiang K, Patel T. Conversion of pyrolytic non-condensable gases from polypropylene co-polymer into bamboo-type carbon nanotubes and high-quality oil using biochar as catalyst. J Environ Manage 2022; 301:113791. [PMID: 34592670 DOI: 10.1016/j.jenvman.2021.113791] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 08/26/2021] [Accepted: 09/18/2021] [Indexed: 06/13/2023]
Abstract
The conversion of low-value plastic waste into high-value products such as carbon nanomaterial is of recent interest. In the current study, the non-condensable pyrolysis gases, produced from Polypropylene Copolymer (PPC) feedstock, was converted into bamboo-type carbon nanotubes (BCNTs) through catalytic chemical vapour deposition using biochar. Experiments were conducted in a three-zone furnace fixed bed reactor, where PPC was pyrolysed in the second zone and carbon nanotubes (CNTs) growth was eventuated in the third zone. The effects of different growth temperatures (500, 700, 900 °C) and biochar particle sizes (nanoparticle as well as 0-100 and 100-300 μm) were investigated to optimise the production of hydrogen and the yield of carbon nanotubes on the biochar surface. Biochar samples used in the synthesis of CNTs were obtained from the pyrolysis of saw dust at 700 °C in a muffle furnace. Analyses performed by using Scanning electron microscopy, Transmission electron microscopy, X-ray diffraction, and Raman spectroscopy techniques suggested that the best crystalline structure of CNTs were obtained at 900 °C with nano-sized biochar as a catalyst. The strong gas-solid contact and void fraction of nano-sized particles enhances the diffusion-precipitation mechanism, leading to the growth of CNTs. The nano-sized biochar increased hydrogen production at 900 °C and reduced the polycyclic aromatic hydrocarbons content in oil to only 1%, which is advantageous for further utilisation. Therefore, the production of high-value CNTs from waste plastic using low-cost biochar catalyst can be a sustainable approach in the management of waste plastic while participating in the circular economy.
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Affiliation(s)
- Kalpit Shah
- Chemical & Environmental Engineering, School of Engineering, RMIT University, Melbourne, Victoria, 3000, Australia; ARC Training Centre for Transformation of Australia's Biosolids Resource, RMIT University, Bundoora, Victoria, 3083, Australia.
| | - Savankumar Patel
- Chemical & Environmental Engineering, School of Engineering, RMIT University, Melbourne, Victoria, 3000, Australia; ARC Training Centre for Transformation of Australia's Biosolids Resource, RMIT University, Bundoora, Victoria, 3083, Australia
| | - Pobitra Halder
- Chemical & Environmental Engineering, School of Engineering, RMIT University, Melbourne, Victoria, 3000, Australia; ARC Training Centre for Transformation of Australia's Biosolids Resource, RMIT University, Bundoora, Victoria, 3083, Australia
| | - Sazal Kundu
- Chemical & Environmental Engineering, School of Engineering, RMIT University, Melbourne, Victoria, 3000, Australia
| | - Mojtaba Hedayati Marzbali
- Chemical & Environmental Engineering, School of Engineering, RMIT University, Melbourne, Victoria, 3000, Australia
| | - Ibrahim Gbolahan Hakeem
- Chemical & Environmental Engineering, School of Engineering, RMIT University, Melbourne, Victoria, 3000, Australia
| | - Biplob Kumar Pramanik
- Civil and Infrastructure Engineering, School of Engineering, RMIT University, Melbourne, Victoria, 3000, Australia
| | - Ken Chiang
- Chemical & Environmental Engineering, School of Engineering, RMIT University, Melbourne, Victoria, 3000, Australia
| | - Tejas Patel
- Chemical & Environmental Engineering, School of Engineering, RMIT University, Melbourne, Victoria, 3000, Australia
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Singh M, Pandey A, Singh S, Singh SP. Iron nanoparticles decorated hierarchical carbon fiber forest for the magnetic solid-phase extraction of multi-pesticide residues from water samples. Chemosphere 2021; 282:131058. [PMID: 34111633 DOI: 10.1016/j.chemosphere.2021.131058] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 05/01/2021] [Accepted: 05/28/2021] [Indexed: 06/12/2023]
Abstract
This study describes a versatile, robust and fast sample pre-concentration novel method based on chemical vapour deposition grown iron nanoparticles dispersed hierarchical carbon fiber forest (Fe-ACF/CNF) for the determination of multi-pesticide residue in water samples. This method was developed by the implementation of Fe-ACF/CNF to magnetic solid-phase extraction method (MSPE) for the adsorption of twenty-nine pesticides of various classes using gas chromatography equipped with an electron capture detector. Fe-ACF/CNF was grown via tip growth mechanism and Fe-nanoparticles are moved to the tip of CNF. The presence of Fe-nanoparticles is responsible for the magnetic property of proposed adsorbents. The Fe-ACF/CNF is competent enough to extract twenty-nine pesticides of different physico-chemical characteristics from water samples. All the predominant parameters including the amount of sorbent desorption time, temperature, sonication effect, regeneration, and reusability of Fe-ACF/CNF were thoroughly investigated. Acceptable linearity was obtained in the range of 20-500 μg/L with a correlation coefficient value ≥ 0.990 for all pesticides. The accuracy of the developed method was evaluated and the obtained recovery of the spiked samples was within 70-120% (standard deviation ≤ 15%) and reusability up to the 4th cycle. The limit of detection and quantification values was in the range of 1.44-5.15 and 4.76-17.0 μg/L, respectively. The obtained results are also cross verified with real water samples from the Gomti river (Lucknow, India) and shown the excellent extraction efficiency of Fe-ACF/CNF.
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Affiliation(s)
- Minu Singh
- Toxicokinetics Laboratory, Regulatory Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), MG Marg, Lucknow, Uttar Pradesh, 226001, India
| | - Anushka Pandey
- Toxicokinetics Laboratory, Regulatory Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), MG Marg, Lucknow, Uttar Pradesh, 226001, India
| | - Shiv Singh
- Industrial Waste Utilization, Nano and Biomaterial Division, CSIR- Advanced Materials and Processes Research Institute (CSIR-AMPRI), Hoshangabad Road, Bhopal, Madhya Pradesh, 462026, India.
| | - Sheelendra Pratap Singh
- Toxicokinetics Laboratory, Regulatory Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), MG Marg, Lucknow, Uttar Pradesh, 226001, India; Analytical Chemistry Laboratory, Regulatory Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), MG Marg, Lucknow, Uttar Pradesh, 226001, India.
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Opoku F, Asare-Donkor NK, Adimado AA. A comprehensive understanding of the chemical vapour deposition of cadmium chalcogenides using Cd[(C6H5)2PSSe]2 single-source precursor: a density functional theory approach. Chem Cent J 2016; 10:4. [PMID: 26839584 PMCID: PMC4736481 DOI: 10.1186/s13065-016-0146-3] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 01/07/2016] [Indexed: 11/12/2022] Open
Abstract
Background The phosphinato complexes of group IIB are of great interest for their potential toward technological applications. A gas phase mechanistic investigation of the chemical vapour deposition of cadmium chalcogenides from the decomposition of Cd[(C6H5)2PSSe]2, as a single source precursor is carried out and reported herein within the framework of density functional theory at the M06/LACVP* level of theory. Results The results reveal that the activation barriers and the product stabilities on the singlet potential energy surface (PES) favour CdS decomposition pathways, respectively. However, on the doublet PES, the activation barriers favour CdS while the product stabilities favour CdSe decomposition pathways, respectively. Contrary to the previously reported theoretical result for Cd[(iPr)2PSSe]2, CdSe decomposition pathways were found to be the major pathways on both the singlet and the doublet PESs, respectively. Conclusion Exploration of the complex gas phase mechanism and a detailed identification of the reaction intermediates enable us to understand and optimise selective growth process that occur in a chemical vapour deposition.Structure of Cd[(C6H5)2PSSe]2 single-source precursor ![]()
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Affiliation(s)
- Francis Opoku
- Department of Chemistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
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Liu J, Liu C, Tan J, Yang B, Wilson T. Super-aperture metrology: overcoming a fundamental limit in imaging smooth highly curved surfaces. J Microsc 2015; 261:300-6. [PMID: 26565890 DOI: 10.1111/jmi.12334] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2015] [Accepted: 09/15/2015] [Indexed: 01/10/2023]
Abstract
The imaging of smooth, highly curved or tilted surfaces is widely recognized as one of the most challenging and unsolved problems in optical imaging and metrology today. The reason is that even when such surfaces are imaged using high aperture microscope objectives the steepness of the features causes the light to be reflected in such a way that it is not captured by the lens. This is true even in the limiting case of unity numerical aperture since the illuminating light may also be reflected in the forward direction. In order to overcome this fundamental problem we have developed a method whereby such specimens are covered with a readily removable organic fluorescent film thereby creating an isotropic scattering surface. We show that we are readily able to detect slopes with angles close 90° using a 0.75 NA objective--an 82% improvement over the theoretical aperture limit. Issues of variation in film thickness deposition are shown to be readily accommodated. This approach may be used with other fluorophore materials, organic or inorganic, since there is no need for biocompatibility in this application.
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Affiliation(s)
- J Liu
- Center of Ultra-Precision Optoelectronic Instrument Engineering, Harbin Institute of Technology, No. 92, West Da-Zhi Street, Harbin, 150001, China
| | - C Liu
- Center of Ultra-Precision Optoelectronic Instrument Engineering, Harbin Institute of Technology, No. 92, West Da-Zhi Street, Harbin, 150001, China
| | - J Tan
- Center of Ultra-Precision Optoelectronic Instrument Engineering, Harbin Institute of Technology, No. 92, West Da-Zhi Street, Harbin, 150001, China
| | - B Yang
- School of Science, Harbin Institute of Technology, No. 92, West Da-Zhi Street, Harbin, 150001, China
| | - T Wilson
- Center of Ultra-Precision Optoelectronic Instrument Engineering, Harbin Institute of Technology, No. 92, West Da-Zhi Street, Harbin, 150001, China.,Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, U.K
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Engels V, Rachamim A, Dalal SH, Pfaendler S, Geng J, Berenguer-Murcia A, Flewitt AJ, Wheatley A. Nanoparticulate PdZn as a Novel Catalyst for ZnO Nanowire Growth. Nanoscale Res Lett 2010; 5:904-907. [PMID: 20672032 PMCID: PMC2894315 DOI: 10.1007/s11671-010-9567-4] [Citation(s) in RCA: 2] [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] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2009] [Accepted: 02/22/2010] [Indexed: 05/29/2023]
Abstract
ZnO nanowires have been grown by chemical vapour deposition (CVD) using PdZn bimetallic nanoparticles to catalyse the process. Nanocatalyst particles with mean particle diameters of 2.6 ± 0.3 nm were shown to catalyse the growth process, displaying activities that compare well with those reported for sputtered systems. Since nanowire diameters are linked to catalyst morphology, the size-control we are able to exhibit during particle preparation represents an advantage over existing approaches in terms of controlling nanowire dimensions, which is necessary in order to utilize the nanowires for catalytic or electrical applications.(See supplementary material 1).
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Affiliation(s)
- Volker Engels
- University of Cambridge Chemical Laboratories, Lensfield Road, Cambridge, CB2 1EW, UK.
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Zervos M, Tsokkou D, Pervolaraki M, Othonos A. Low Temperature Growth of In2O3and InN Nanocrystals on Si(111) via Chemical Vapour Deposition Based on the Sublimation of NH4Cl in In. Nanoscale Res Lett 2009; 4:491-7. [PMID: 20596336 PMCID: PMC2894321 DOI: 10.1007/s11671-009-9266-1] [Citation(s) in RCA: 3] [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] [Subscribe] [Scholar Register] [Received: 11/30/2008] [Accepted: 01/27/2009] [Indexed: 05/29/2023]
Abstract
Indium oxide (In2O3) nanocrystals (NCs) have been obtained via atmospheric pressure, chemical vapour deposition (APCVD) on Si(111) via the direct oxidation of In with Ar:10% O2at 1000 °C but also at temperatures as low as 500 °C by the sublimation of ammonium chloride (NH4Cl) which is incorporated into the In under a gas flow of nitrogen (N2). Similarly InN NCs have also been obtained using sublimation of NH4Cl in a gas flow of NH3. During oxidation of In under a flow of O2the transfer of In into the gas stream is inhibited by the formation of In2O3around the In powder which breaks up only at high temperatures, i.e.T > 900 °C, thereby releasing In into the gas stream which can then react with O2leading to a high yield formation of isolated 500 nm In2O3octahedrons but also chains of these nanostructures. No such NCs were obtained by direct oxidation forTG < 900 °C. The incorporation of NH4Cl in the In leads to the sublimation of NH4Cl into NH3and HCl at around 338 °C which in turn produces an efficient dispersion and transfer of the whole In into the gas stream of N2where it reacts with HCl forming primarily InCl. The latter adsorbs onto the Si(111) where it reacts with H2O and O2leading to the formation of In2O3nanopyramids on Si(111). The rest of the InCl is carried downstream, where it solidifies at lower temperatures, and rapidly breaks down into metallic In upon exposure to H2O in the air. Upon carrying out the reaction of In with NH4Cl at 600 °C under NH3as opposed to N2, we obtain InN nanoparticles on Si(111) with an average diameter of 300 nm.
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Affiliation(s)
- Matthew Zervos
- Department of Mechanical and Manufacturing Engineering, Materials Science Group, Nanostructured Materials and Devices Laboratory, University of Cyprus, P,O, Box 20537, 1678, Nicosia, Cyprus.
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