1
|
Chen L, Allec SI, Nguyen MT, Kovarik L, Hoffman AS, Hong J, Meira D, Shi H, Bare SR, Glezakou VA, Rousseau R, Szanyi J. Dynamic Evolution of Palladium Single Atoms on Anatase Titania Support Determines the Reverse Water-Gas Shift Activity. J Am Chem Soc 2023; 145:10847-10860. [PMID: 37145876 DOI: 10.1021/jacs.3c02326] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Research interest in single-atom catalysts (SACs) has been continuously increasing. However, the lack of understanding of the dynamic behaviors of SACs during applications hinders catalyst development and mechanistic understanding. Herein, we report on the evolution of active sites over Pd/TiO2-anatase SAC (Pd1/TiO2) in the reverse water-gas shift (rWGS) reaction. Combining kinetics, in situ characterization, and theory, we show that at T ≥ 350 °C, the reduction of TiO2 by H2 alters the coordination environment of Pd, creating Pd sites with partially cleaved Pd-O interfacial bonds and a unique electronic structure that exhibit high intrinsic rWGS activity through the carboxyl pathway. The activation by H2 is accompanied by the partial sintering of single Pd atoms (Pd1) into disordered, flat, ∼1 nm diameter clusters (Pdn). The highly active Pd sites in the new coordination environment under H2 are eliminated by oxidation, which, when performed at a high temperature, also redisperses Pdn and facilitates the reduction of TiO2. In contrast, Pd1 sinters into crystalline, ∼5 nm particles (PdNP) during CO treatment, deactivating Pd1/TiO2. During the rWGS reaction, the two Pd evolution pathways coexist. The activation by H2 dominates, leading to the increasing rate with time-on-stream, and steady-state Pd active sites similar to the ones formed under H2. This work demonstrates how the coordination environment and nuclearity of metal sites on a SAC evolve during catalysis and pretreatments and how their activity is modulated by these behaviors. These insights on SAC dynamics and the structure-function relationship are valuable to mechanistic understanding and catalyst design.
Collapse
Affiliation(s)
- Linxiao Chen
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Sarah I Allec
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Manh-Thuong Nguyen
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Libor Kovarik
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Adam S Hoffman
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Jiyun Hong
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Debora Meira
- Canadian Light Source Inc., 44 Innovation Boulevard, Saskatoon, Saskatchewan S7N 2V3, Canada
| | - Honghong Shi
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Simon R Bare
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | | | - Roger Rousseau
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - János Szanyi
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| |
Collapse
|
2
|
Ullah S, Ferreira-Neto EP, Khan AA, Medeiros IPM, Wender H. Supported nanostructured photocatalysts: the role of support-photocatalyst interactions. PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES : OFFICIAL JOURNAL OF THE EUROPEAN PHOTOCHEMISTRY ASSOCIATION AND THE EUROPEAN SOCIETY FOR PHOTOBIOLOGY 2023; 22:219-240. [PMID: 36178668 DOI: 10.1007/s43630-022-00299-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 09/05/2022] [Indexed: 01/12/2023]
Abstract
Heterogeneous photocatalysis employing semiconductor oxide photocatalysts is a sustainable and promising method for environmental remediation and clean energy generation. In this context, nanostructured photocatalysts, with at least one dimension in the 1‒100 nm size regime, have attracted ever-growing attention due to their unique and often enhanced size-dependent physicochemical properties. While their reduced size ensures enhanced photocatalytic performance, the same makes it difficult and time/energy-demanding to remove/recover such nanostructured photocatalysts from aqueous media. This fundamental limitation has paved the way towards developing supported nanophotocatalysts where the active photocatalytic nanostructures are coated on the surface of polymeric or inorganic support materials, often in a core@shell conformation. This arrangement solves the problem of photocatalysts' recovery for effective reuse or recycling and leads to improved and desired target properties due to specific photocatalyst-support interactions. While the enhanced physicochemical properties of supported photocatalysts have been widely studied in many target applications, the role of support-photocatalysts interactions in improving these properties remains unexplored. This review article provides an updated viewpoint on the photocatalyst-support interactions and the resulting unique physiochemical properties important for diverse photochemical applications and the design of practical devices. While exploring the properties of supported nanostructured metal oxide/sulfides photocatalysts such as TiO2 and MoS2, we also briefly discuss the common strategies employed to coat the active nanomaterials on the surface of different supports (organic/polymeric, inorganic, active, inert, and magnetic).
Collapse
Affiliation(s)
- Sajjad Ullah
- Institute of Chemical Sciences, University of Peshawar, PO Box 25120, Peshawar, Pakistan.
| | - Elias P Ferreira-Neto
- Department of Chemistry, Federal University of Santa Catarina (UFSC), Florianópolis, Santa Catarina, 88040-900, Brazil
| | - Abrar A Khan
- Institute of Chemical Sciences, University of Peshawar, PO Box 25120, Peshawar, Pakistan
| | - Isaac P M Medeiros
- Nano & Photon Research Group, Laboratory of Nanomaterials and Applied Nanotechnology (LNNA), Institute of Physics, Federal University of Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul, 79070-900, Brazil
| | - Heberton Wender
- Nano & Photon Research Group, Laboratory of Nanomaterials and Applied Nanotechnology (LNNA), Institute of Physics, Federal University of Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul, 79070-900, Brazil.
| |
Collapse
|
3
|
Chen L, Kovarik L, Meira D, Szanyi J. Differentiating and Understanding the Effects of Bulk and Surface Mo Doping on CO 2 Hydrogenation over Pd/Anatase-TiO 2. ACS Catal 2022. [DOI: 10.1021/acscatal.2c03181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Linxiao Chen
- Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Libor Kovarik
- Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Debora Meira
- CLS@APS Sector 20, Advanced Photon Source, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, Illinois 60439, United States
- Canadian Light Source Inc., 44 Innovation Boulevard, Saskatoon, Saskatchewan S7N 2V3, Canada
| | - János Szanyi
- Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| |
Collapse
|
4
|
Moussa I, Ibrahim H, Emam EAM, Tawfik TM. Structure, light absorption properties and photocatalytic activity of carbon-containing titania nanocomposites synthesized via a facile sol-gel method. Heliyon 2022; 8:e10199. [PMID: 36033305 PMCID: PMC9404286 DOI: 10.1016/j.heliyon.2022.e10199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 05/25/2022] [Accepted: 08/03/2022] [Indexed: 11/25/2022] Open
Abstract
Facile and green sol–gel method was used to synthesize carbon-containing titania nanopowder, and diethanolamine (DEA) was used as the in situ carbon source. The titania gel was heat treated at temperatures ranging from 300 to 700 °C. X-ray diffraction (XRD), thermal analysis, and Raman spectroscopy reported no crystalline phase at <325 °C. Crystallization of the anatase phase with traces of brookite phases was observed at T > 325 °C, followed by a transformation to anatase/rutile in the range of 400 °C < T ≤ 650 °C. Finally, the complete phase transformation to the rutile phase occurs at temperatures of T > 650 °C. High-resolution electron microscopy (HREM) micrographs confirm the coexistence of anatase and rutile nanocrystals and amorphous carbon clusters in the composite samples. Chemical element analysis via X-ray photoelectron spectroscopy (XPS) indicated nonstoichiometry in the O/Ti ratio, the presence of (Ti3+) oxidation state, and elemental carbon. Thermogravimetric (TG) measurements are the most accurate method to measure the carbon content in samples. UV-vis spectroscopy demonstrated considerable enhancement in the optical absorption properties and electronic structure of prepared samples compared to the pure anatase and rutile. This enhancement is strongly correlated with the structure and composition of prepared samples and consequently depends on the preparation method as well as conditions. Innovative features such as self-cleaning action was demonstrated in carbon containing titanate nanocomposite.
Collapse
Affiliation(s)
- Ibrahim Moussa
- Solid State Physics Department, Physics Research Institute, National Research Centre, 33 El Buhouth St., Dokki, Giza, 12622, Egypt
| | - Hassan Ibrahim
- Pretreatment and Finishing of Cellulosic Fibers Dept., Textile Research and Technology Institute, National Research Centre, 33 El Bohouth st., Dokki, P.O.12622, Cairo, Egypt
| | - El-Amir M Emam
- Faculty of Applied Arts, Textile Printing, Dyeing and Finishing Department, Helwan University, Cairo, Egypt
| | - Tawfik M Tawfik
- Faculty of Applied Arts, Textile Printing, Dyeing and Finishing Department, Benha University, Benha, Egypt
| |
Collapse
|
5
|
Chen L, Unocic RR, Hoffman AS, Hong J, Braga AH, Bao Z, Bare SR, Szanyi J. Unlocking the Catalytic Potential of TiO 2-Supported Pt Single Atoms for the Reverse Water-Gas Shift Reaction by Altering Their Chemical Environment. JACS AU 2021; 1:977-986. [PMID: 34467344 PMCID: PMC8395703 DOI: 10.1021/jacsau.1c00111] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Indexed: 05/05/2023]
Abstract
Single-atom catalysts (SACs) often exhibit dynamic responses to the reaction and pretreatment environment that affect their activity. The lack of understanding of these behaviors hinders the development of effective, stable SACs, and makes their investigations rather difficult. Here we report a reduction-oxidation cycle that induces nearly 5-fold activity enhancement on Pt/TiO2 SACs for the reverse water-gas shift (rWGS) reaction. We combine microscopy (STEM) and spectroscopy (XAS and IR) studies with kinetic measurements, to convincingly show that the low activity on the fresh SAC is a result of limited accessibility of Pt single atoms (Pt1) due to high Pt-O coordination. The reduction step mobilizes Pt1, forming small, amorphous, and unstable Pt aggregates. The reoxidation step redisperses Pt into Pt1, but in a new, less O-coordinated chemical environment that makes the single metal atoms more accessible and, consequently, more active. After the cycle, the SAC exhibits superior rWGS activity to nonatomically dispersed Pt/TiO2. During the rWGS, the activated Pt1 experience slow deactivation, but can be reactivated by mild oxidation. This work demonstrates a clear picture of how the structural evolution of Pt/TiO2 SACs leads to ultimate catalytic efficiency, offering desired understanding on the rarely explored dynamic chemical environment of supported single metal atoms and its catalytic consequences.
Collapse
Affiliation(s)
- Linxiao Chen
- Institute
for Integrated Catalysis, Pacific Northwest
National Laboratory, Richland, Washington 99352, United States
| | - Raymond R. Unocic
- Center
for Nanophase Materials Science, Oak Ridge
National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Adam S. Hoffman
- Stanford
Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Jiyun Hong
- Stanford
Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Adriano H. Braga
- Institute
of Chemistry, University of São Paulo, São Paulo, São
Paulo 05508-000, Brazil
| | - Zhenghong Bao
- Chemical
Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Simon R. Bare
- Stanford
Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Janos Szanyi
- Institute
for Integrated Catalysis, Pacific Northwest
National Laboratory, Richland, Washington 99352, United States
| |
Collapse
|
6
|
Yuwono JA, Burr P, Galvin C, Lennon A. Atomistic Insights into Lithium Storage Mechanisms in Anatase, Rutile, and Amorphous TiO 2 Electrodes. ACS APPLIED MATERIALS & INTERFACES 2021; 13:1791-1806. [PMID: 33393758 DOI: 10.1021/acsami.0c17097] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Density functional theory calculations were used to investigate the phase transformations of LixTiO2 (at 0 ≤ x ≤ 1), solid-state Li+ diffusion, and interfacial charge-transfer reactions in both crystalline and amorphous forms of TiO2. It is shown that in contrast to crystalline TiO2 polymorphs, the energy barrier to Li+ diffusion in amorphous TiO2 decreases with increasing mole fraction of Li+ due to the changes of chemical species pair interactions following the progressive filling of low-energy Li+ trapping sites. Sites with longer Li-Ti and Li-O interactions exhibit lower Li+ insertion energies and higher migration energy barriers. Due to its disordered atomic arrangement and increasing Li+ diffusivity at higher mole fractions, amorphous TiO2 exhibits both surface and bulk storage mechanisms. The results suggest that nanostructuring of crystalline TiO2 can increase both the rate and capacity because the capacity dependence on the bulk storage mechanism is minimized and replaced with the surface storage mechanism. These insights into Li+ storage mechanisms in different forms of TiO2 can guide the fabrication of TiO2 electrodes to maximize the capacity and rate performance in the future.
Collapse
Affiliation(s)
- Jodie A Yuwono
- School of Photovoltaic and Renewable Energy Engineering, UNSW Sydney, Kensington, Sydney, New South Wales 2052, Australia
| | - Patrick Burr
- School of Mechanical and Manufacturing Engineering, UNSW Sydney, Kensington, Sydney, New South Wales 2052, Australia
| | - Conor Galvin
- School of Mechanical and Manufacturing Engineering, UNSW Sydney, Kensington, Sydney, New South Wales 2052, Australia
| | - Alison Lennon
- School of Photovoltaic and Renewable Energy Engineering, UNSW Sydney, Kensington, Sydney, New South Wales 2052, Australia
| |
Collapse
|
7
|
Kim S, De Bruyn M, Alauzun JG, Louvain N, Brun N, Macquarrie DJ, Stievano L, Mutin PH, Monconduit L, Boury B. Dehydration of Alginic Acid Cryogel by TiCl 4 vapor: Direct Access to Mesoporous TiO 2 @C Nanocomposites and Their Performance in Lithium-Ion Batteries. CHEMSUSCHEM 2019; 12:2660-2670. [PMID: 30950578 DOI: 10.1002/cssc.201900781] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 04/01/2019] [Indexed: 06/09/2023]
Abstract
A new strategy for the synthesis of mesoporous TiO2 @C nanocomposites through the direct mineralization of seaweed-derived alginic acid cryogel by TiCl4 through a solid/vapor reaction pathway is presented. In this synthesis, alginic acid cryogel can have multiple roles; i) mesoporous template, ii) carbon source, and iii) oxygen source for the TiO2 precursor, TiCl4 . The resulting TiO2 @alginic acid composite was transformed either into pure mesoporous TiO2 by calcination or into mesoporous TiO2 @C nanocomposites by pyrolysis. By comparing with a nonporous TiO2 @C composite, the importance of the mesopores on the performance of electrodes for lithium-ion batteries based on mesoporous TiO2 @C composite was clearly evidenced. In addition, the carbon matrix in the mesoporous TiO2 @C nanocomposite also showed electrochemical activity versus lithium ions, providing twice the capacity of pure mesoporous TiO2 or alginic acid-derived mesoporous carbon (A600). Given the simplicity and environmental friendliness of the process, the mesoporous TiO2 @C nanocomposite could satisfy the main prerequisites of green and sustainable chemistry while showing improved electrochemical performance as a negative electrode for lithium-ion batteries.
Collapse
Affiliation(s)
- Sanghoon Kim
- Institut Charles Gerhardt Montpellier, UMR 5253 Univ. Montpellier-CNRS-ENSCM, Montpellier, France
| | - Mario De Bruyn
- Green Chemistry Centre of Excellence, University of York, York, North Yorkshire, YO10, 5DD, UK
| | - Johan G Alauzun
- Institut Charles Gerhardt Montpellier, UMR 5253 Univ. Montpellier-CNRS-ENSCM, Montpellier, France
| | - Nicolas Louvain
- Institut Charles Gerhardt Montpellier, UMR 5253 Univ. Montpellier-CNRS-ENSCM, Montpellier, France
- Réseau sur le Stockage Electrochimique de l'Energie (RS2E), CNRS, FR3459, 33 Rue Saint Leu, 80039, Amiens Cedex, France
| | - Nicolas Brun
- Institut Charles Gerhardt Montpellier, UMR 5253 Univ. Montpellier-CNRS-ENSCM, Montpellier, France
| | - Duncan J Macquarrie
- Green Chemistry Centre of Excellence, University of York, York, North Yorkshire, YO10, 5DD, UK
| | - Lorenzo Stievano
- Institut Charles Gerhardt Montpellier, UMR 5253 Univ. Montpellier-CNRS-ENSCM, Montpellier, France
- Réseau sur le Stockage Electrochimique de l'Energie (RS2E), CNRS, FR3459, 33 Rue Saint Leu, 80039, Amiens Cedex, France
| | - P Hubert Mutin
- Institut Charles Gerhardt Montpellier, UMR 5253 Univ. Montpellier-CNRS-ENSCM, Montpellier, France
| | - Laure Monconduit
- Institut Charles Gerhardt Montpellier, UMR 5253 Univ. Montpellier-CNRS-ENSCM, Montpellier, France
- Réseau sur le Stockage Electrochimique de l'Energie (RS2E), CNRS, FR3459, 33 Rue Saint Leu, 80039, Amiens Cedex, France
| | - Bruno Boury
- Institut Charles Gerhardt Montpellier, UMR 5253 Univ. Montpellier-CNRS-ENSCM, Montpellier, France
| |
Collapse
|
8
|
Sarkar A, Khan GG. The formation and detection techniques of oxygen vacancies in titanium oxide-based nanostructures. NANOSCALE 2019; 11:3414-3444. [PMID: 30734804 DOI: 10.1039/c8nr09666j] [Citation(s) in RCA: 129] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
TiO2 and other titanium oxide-based nanomaterials have drawn immense attention from researchers in different scientific domains due to their fascinating multifunctional properties, relative abundance, environmental friendliness, and bio-compatibility. However, the physical and chemical properties of titanium oxide-based nanomaterials are found to be explicitly dependent on the presence of various crystal defects. Oxygen vacancies are the most common among them and have always been the subject of both theoretical and experimental research as they play a crucial role in tuning the inherent properties of titanium oxides. This review highlights different strategies for effectively introducing oxygen vacancies in titanium oxide-based nanomaterials, as well as a discussion on the positions of oxygen vacancies inside the TiO2 band gap based on theoretical calculations. Additionally, a detailed review of different experimental techniques that are extensively used for identifying oxygen vacancies in TiO2 nanostructures is also presented.
Collapse
Affiliation(s)
- Ayan Sarkar
- Centre for Research in Nanoscience and Nanotechnology, University of Calcutta, Block-JD2, Sector-III, Salt Lake, Kolkata 700106, West Bengal, India.
| | | |
Collapse
|
9
|
Effect of standard light illumination on electrolyte's stability of lithium-ion batteries based on ethylene and di-methyl carbonates. Sci Rep 2019; 9:135. [PMID: 30644414 PMCID: PMC6333783 DOI: 10.1038/s41598-018-36836-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 11/23/2018] [Indexed: 11/08/2022] Open
Abstract
Combining energy conversion and storage at a device and/or at a molecular level constitutes a new research field raising interest. This work aims at investigating how prolonged standard light exposure (A.M. 1.5G) interacts with conventional batteries electrolyte, commonly used in the photo-assisted or photo-rechargeable batteries, based on 1 mol.L-1 LiPF6 EC/DMC electrolyte. We demonstrate the intrinsic chemical robustness of this class of electrolyte in absence of any photo-electrodes. However, based on different steady-state and time-resolved spectroscopic techniques, it is for the first time highlighted that the solvation of lithium and hexafluorophosphate ions by the carbonates are modified by light exposure leading to absorbance and ionic conductivity modifications without detrimental effects onto the electrochemical properties.
Collapse
|
10
|
Chapman BS, Mishra SR, Tracy JB. Direct electrospinning of titania nanofibers with ethanol. Dalton Trans 2019; 48:12822-12827. [DOI: 10.1039/c9dt01872g] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
TiO2 nanofibers with average diameters of ∼70 nm were prepared by direct electrospinning.
Collapse
Affiliation(s)
- Brian S. Chapman
- Department of Materials Science and Engineering
- North Carolina State University
- Raleigh
- USA
| | - Sumeet R. Mishra
- Department of Materials Science and Engineering
- North Carolina State University
- Raleigh
- USA
| | - Joseph B. Tracy
- Department of Materials Science and Engineering
- North Carolina State University
- Raleigh
- USA
| |
Collapse
|
11
|
Milošević I, Rtimi S, Jayaprakash A, van Driel B, Greenwood B, Aimable A, Senna M, Bowen P. Synthesis and characterization of fluorinated anatase nanoparticles and subsequent N-doping for efficient visible light activated photocatalysis. Colloids Surf B Biointerfaces 2018; 171:445-450. [DOI: 10.1016/j.colsurfb.2018.07.035] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 06/22/2018] [Accepted: 07/16/2018] [Indexed: 10/28/2022]
|
12
|
Livraghi S, Barbero N, Agnoli S, Barolo C, Granozzi G, Sauvage F, Giamello E. A multi-technique comparison of the electronic properties of pristine and nitrogen-doped polycrystalline SnO2. Phys Chem Chem Phys 2018; 18:22617-27. [PMID: 27477515 DOI: 10.1039/c6cp02822e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Nitrogen doped tin(iv) oxide (SnO2) materials in the form of nanometric powders have been prepared by precipitation with ammonia. Their properties have been compared with those of undoped materials obtained in a similar way using various physical techniques such as photoelectron spectroscopies (XPS and UPS), UV-Vis-NIR spectroscopy and electron paramagnetic resonance (EPR). Nitrogen doping leads to the formation of various nitrogen containing species, the more relevant of which is a nitride-type ionic species, based on the substitution of a lattice oxygen atom with a nitrogen atom. This species exists in two forms, paramagnetic (hole centre, formally N(2-)) and diamagnetic (N(3-)). The mutual ratio of the two species varies according to the oxidation state of the material. The doped solid, like most of the semiconducting oxides, tends to lose oxygen forming oxygen vacancies upon annealing under vacuum and leaving an excess of electrons in the solid. The stoichiometry of the solid can thus be markedly changed depending on the external conditions. Excess electrons are present both as itinerant electrons in the conduction band and as Sn(ii) states lying close to the valence band maximum. The presence of nitride-type centres, which are low energy states located below the top of the valence band, decreases the energy cost for the formation of oxygen vacancies by O2 release from the lattice. This particular feature of the doped system represents a severe limit to the preparation of a p-type SnO2via nitrogen doping.
Collapse
Affiliation(s)
- S Livraghi
- Dipartimento di Chimica, Università di Torino and NIS, Centre for Nanostructured Interfaces and Surfaces, Via P. Giuria 7, I - 10125 Torino, Italy
| | - N Barbero
- Dipartimento di Chimica, Università di Torino and NIS, Centre for Nanostructured Interfaces and Surfaces, Via P. Giuria 7, I - 10125 Torino, Italy and Laboratoire de Réactivité et Chimie des Solides, Université de Picardie Jules Verne, CNRS UMR 7314, 33 rue Saint Leu, 80039 Amiens, France
| | - S Agnoli
- Dipartimento di Scienze Chimiche, Università di Padova, Via Marzolo 1, 35131 Padova, Italy
| | - C Barolo
- Dipartimento di Chimica, Università di Torino and NIS, Centre for Nanostructured Interfaces and Surfaces, Via P. Giuria 7, I - 10125 Torino, Italy
| | - G Granozzi
- Dipartimento di Scienze Chimiche, Università di Padova, Via Marzolo 1, 35131 Padova, Italy
| | - F Sauvage
- Laboratoire de Réactivité et Chimie des Solides, Université de Picardie Jules Verne, CNRS UMR 7314, 33 rue Saint Leu, 80039 Amiens, France
| | - E Giamello
- Dipartimento di Chimica, Università di Torino and NIS, Centre for Nanostructured Interfaces and Surfaces, Via P. Giuria 7, I - 10125 Torino, Italy
| |
Collapse
|
13
|
Fischer MG, Hua X, Wilts BD, Gunkel I, Bennett TM, Steiner U. Mesoporous Titania Microspheres with Highly Tunable Pores as an Anode Material for Lithium Ion Batteries. ACS APPLIED MATERIALS & INTERFACES 2017; 9:22388-22397. [PMID: 28609102 DOI: 10.1021/acsami.7b03155] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Mesoporous titania microspheres (MTMs) have been employed in many applications, including (photo)catalysis as well as energy conversion and storage. Their morphology offers a hierarchical structural design motif that lends itself to being incorporated into established large-scale fabrication processes. Despite the fact that device performance hinges on the precise morphological characteristics of these materials, control over the detailed mesopore structure and the tunability of the pore size remains a challenge. Especially the accessibility of a wide range of mesopore sizes by the same synthesis method is desirable, as this would allow for a comparative study of the relationship between structural features and performance. Here, we report a method that combines sol-gel chemistry with polymer micro- and macrophase separation to synthesize porous titania spheres with diameters in the micrometer range. The as-prepared MTMs exhibit well-defined, accessible porosities with mesopore sizes adjustable by the choice of the polymers. When applied as an anode material in lithium ion batteries (LIBs), the MTMs demonstrate excellent performance. The influence of the pore size and an in situ carbon coating on charge transport and storage is examined, providing important insights for the optimization of structured titania anodes in LIBs. Our synthesis strategy presents a facile one-pot approach that can be applied to different structure-directing agents and inorganic materials, thus further extending its scope of application.
Collapse
Affiliation(s)
- Michael G Fischer
- Adolphe Merkle Institute, Université de Fribourg , Chemin des Verdiers 4, 1700 Fribourg, Switzerland
| | - Xiao Hua
- Adolphe Merkle Institute, Université de Fribourg , Chemin des Verdiers 4, 1700 Fribourg, Switzerland
| | - Bodo D Wilts
- Adolphe Merkle Institute, Université de Fribourg , Chemin des Verdiers 4, 1700 Fribourg, Switzerland
| | - Ilja Gunkel
- Adolphe Merkle Institute, Université de Fribourg , Chemin des Verdiers 4, 1700 Fribourg, Switzerland
| | - Thomas M Bennett
- School of Chemistry, University of Nottingham , University Park, Nottingham NG7 2RD, United Kingdom
| | - Ullrich Steiner
- Adolphe Merkle Institute, Université de Fribourg , Chemin des Verdiers 4, 1700 Fribourg, Switzerland
| |
Collapse
|
14
|
Lamiel-Garcia O, Cuko A, Calatayud M, Illas F, Bromley ST. Predicting size-dependent emergence of crystallinity in nanomaterials: titania nanoclusters versus nanocrystals. NANOSCALE 2017; 9:1049-1058. [PMID: 27809322 DOI: 10.1039/c6nr05788h] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Bottom-up and top-down derived nanoparticle structures refined by accurate ab initio calculations are used to investigate the size dependent emergence of crystallinity in titania from the monomer upwards. Global optimisation and data mining are used to provide a series of (TiO2)N global minima candidates in the range N = 1-38, where our approach provides many new low energy structures for N > 10. A range of nanocrystal cuts from the anatase crystal structure are also considered up to a size of over 250 atoms. All nanocrystals considered are predicted to be metastable with respect to non-crystalline nanoclusters, which has implications with respect to the limitations of the cluster approach to modelling large titania nanosystems. Extrapolating both data sets using a generalised expansion of a top-down derived energy expression for nanoparticles, we obtain an estimate of the non-crystalline to crystalline crossover size for titania. Our results compare well with the available experimental results and imply that anatase-like crystallinity emerges in titania nanoparticles of approximately 2-3 nm diameter.
Collapse
Affiliation(s)
- Oriol Lamiel-Garcia
- Departament de Ciència de Materials i Química Física and Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, E-08028 Barcelona, Spain
| | - Andi Cuko
- Departament de Ciència de Materials i Química Física and Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, E-08028 Barcelona, Spain and SorbonneUniversités, UPMC Univ Paris 06, CNRS, Laboratoire de Chimie Théorique CC 137, 4, place Jussieu F. 75252, Paris Cedex 05, France
| | - Monica Calatayud
- SorbonneUniversités, UPMC Univ Paris 06, CNRS, Laboratoire de Chimie Théorique CC 137, 4, place Jussieu F. 75252, Paris Cedex 05, France and InstitutUniversitaire de France, France
| | - Francesc Illas
- Departament de Ciència de Materials i Química Física and Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, E-08028 Barcelona, Spain
| | - Stefan T Bromley
- Departament de Ciència de Materials i Química Física and Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, E-08028 Barcelona, Spain and Institució Catalana de Recerca i Estudis Avançats (ICREA), E-08010 Barcelona, Spain.
| |
Collapse
|
15
|
Verma R, Gangwar J, Srivastava AK. Multiphase TiO2nanostructures: a review of efficient synthesis, growth mechanism, probing capabilities, and applications in bio-safety and health. RSC Adv 2017. [DOI: 10.1039/c7ra06925a] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
This review article provides an exhaustive overview of efficient synthesis, growth mechanism and research activities of multiphase TiO2nanostructures to provide their structural, morphological, optical and biological properties co-relations.
Collapse
Affiliation(s)
- Rajni Verma
- Academy of Scientific and Innovative Research
- CSIR – National Physical Laboratory
- New Delhi – 110 012
- India
- Sophisticated and Analytical Equipments Division
| | - Jitendra Gangwar
- Sophisticated and Analytical Equipments Division
- CSIR – National Physical Laboratory
- New Delhi – 110 012
- India
- Department of Physics
| | - Avanish K. Srivastava
- Academy of Scientific and Innovative Research
- CSIR – National Physical Laboratory
- New Delhi – 110 012
- India
- Sophisticated and Analytical Equipments Division
| |
Collapse
|
16
|
Patra S, Andriamiadamanana C, Tulodziecki M, Davoisne C, Taberna PL, Sauvage F. Low-temperature electrodeposition approach leading to robust mesoscopic anatase TiO2 films. Sci Rep 2016; 6:21588. [PMID: 26911529 PMCID: PMC4766494 DOI: 10.1038/srep21588] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 01/25/2016] [Indexed: 11/13/2022] Open
Abstract
Anatase TiO2, a wide bandgap semiconductor, likely the most worldwide studied inorganic material for many practical applications, offers unequal characteristics for applications in photocatalysis and sun energy conversion. However, the lack of controllable, cost-effective methods for scalable fabrication of homogeneous thin films of anatase TiO2 at low temperatures (ie. < 100 °C) renders up-to-date deposition processes unsuited to flexible plastic supports or to smart textile fibres, thus limiting these wearable and easy-to-integrate emerging technologies. Here, we present a very versatile template-free method for producing robust mesoporous films of nanocrystalline anatase TiO2 at temperatures of/or below 80 °C. The individual assembly of the mesoscopic particles forming ever-demonstrated high optical quality beads of TiO2 affords, with this simple methodology, efficient light capture and confinement into the photo-anode, which in flexible dye-sensitized solar cell technology translates into a remarkable power conversion efficiency of 7.2% under A.M.1.5G conditions.
Collapse
Affiliation(s)
- Snehangshu Patra
- Laboratoire de Réactivité et Chimie des Solides, Université de Picardie Jules Verne, CNRS UMR 7314, 33, rue Saint Leu, 80039 Amiens, France
- Réseau sur le Stockage Electrochimique de l’Energie (RS2E), FR CNRS 3459, France
| | - Christian Andriamiadamanana
- Laboratoire de Réactivité et Chimie des Solides, Université de Picardie Jules Verne, CNRS UMR 7314, 33, rue Saint Leu, 80039 Amiens, France
- Réseau sur le Stockage Electrochimique de l’Energie (RS2E), FR CNRS 3459, France
| | - Michal Tulodziecki
- Laboratoire de Réactivité et Chimie des Solides, Université de Picardie Jules Verne, CNRS UMR 7314, 33, rue Saint Leu, 80039 Amiens, France
| | - Carine Davoisne
- Laboratoire de Réactivité et Chimie des Solides, Université de Picardie Jules Verne, CNRS UMR 7314, 33, rue Saint Leu, 80039 Amiens, France
- Réseau sur le Stockage Electrochimique de l’Energie (RS2E), FR CNRS 3459, France
| | - Pierre-Louis Taberna
- Réseau sur le Stockage Electrochimique de l’Energie (RS2E), FR CNRS 3459, France
- Université Paul Sabatier, Toulouse III, CIRIMAT, CNRS UMR 5085, 118, Route de Narbonne, 31062 Toulouse cedex 09, France
| | - Frédéric Sauvage
- Laboratoire de Réactivité et Chimie des Solides, Université de Picardie Jules Verne, CNRS UMR 7314, 33, rue Saint Leu, 80039 Amiens, France
- Réseau sur le Stockage Electrochimique de l’Energie (RS2E), FR CNRS 3459, France
| |
Collapse
|
17
|
Sabyrov K, Penn RL. A kinetic model for two-step phase transformation of hydrothermally treated nanocrystalline anatase. CrystEngComm 2016. [DOI: 10.1039/c6ce00022c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
|
18
|
A photo-(electro)-catalytic system illustrating the effect of lithium ions on titania surface energetics and charge transfer. J Electroanal Chem (Lausanne) 2015. [DOI: 10.1016/j.jelechem.2015.07.035] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|