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Li W, Lu G, Ding Y, Cong R, Yang T. Ba 3SnGa 10-xIn xO 20 (0 ≤ x ≤ 2): site-selective doping, band structure engineering and photocatalytic overall water splitting. Dalton Trans 2024; 53:6747-6757. [PMID: 38530769 DOI: 10.1039/d4dt00340c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/28/2024]
Abstract
Developing new photocatalysts and deciphering the structure-property relationship are always the central topics in photocatalysis. In this study, a new photocatalyst Ba3SnGa10O20 containing two d10 metal cations was prepared by a high temperature solid state reaction, and its crystal structure was investigated by Rietveld refinements of monochromatic X-ray powder diffraction data for the first time. There are 2 Ba, 4 metal cations and 6 O independent atoms in a unit cell. Sn4+ and Ga3+ co-occupy the octahedral cavities named M1 and M2 sites, and the other two metal sites are fully occupied by Ga3+. Rational In3+-to-Ga3+ substitution was performed to reduce the potential of the conduction band minimum and enhance the light absorption ability, which was indeed confirmed using UV-vis diffuse reflectance spectra and Mott-Schottky plots for Ba3SnGa10-xInxO20 (0 ≤ x ≤ 2). Interestingly, In3+ exhibits site selective doping at M1 and M2 sites exclusively. With the light absorption ability enhanced, the photocatalytic overall water splitting activity was also improved, i.e. the photocatalytic H2 generation rate was 1.7(1) μmol h-1 for Ba3SnGa10O20, and the optimal catalyst Ba3SnGa8.5In1.5O20 loaded with 1.0 wt% Pd exhibited the H2 generation rate of 27.5(4) μmol h-1 and the apparent quantum yield at 254 nm was estimated to be 2.28% in pure water.
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Affiliation(s)
- Weihua Li
- College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 401331, People's Republic of China.
| | - Guangxiang Lu
- College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 401331, People's Republic of China.
| | - Yanhong Ding
- College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 401331, People's Republic of China.
| | - Rihong Cong
- College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 401331, People's Republic of China.
| | - Tao Yang
- College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 401331, People's Republic of China.
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Lv Y, Sun Y, Xu J, Xu X, Fernández-Carrión AJ, Wei T, Yi H, Kuang X. Phase Evolution, Electrical Properties, and Conduction Mechanism of Ca 12Al 14-xGa xO 33 (0 ≤ x ≤ 14) Ceramics Synthesized by a Glass Crystallization Method. Inorg Chem 2021; 60:2446-2456. [PMID: 33535755 DOI: 10.1021/acs.inorgchem.0c03344] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Mayenite Ca12Al14O33, as an oxide-ion conductor, has the potential of being applied in many fields, such as solid-oxide fuel cells. However, its relatively low oxide-ion conductivity hinders its wide practical applications and thus needs to be further optimized. Herein, a new recently developed glass crystallization route was used to prepare a series of Ga-doped Ca12Al14-xGaxO33 (0 ≤ x ≤ 14) materials, which is not accessible by the traditional solid-state reaction method. Phase evolution with the content of gallium, the corresponding structures, and their electrical properties were studied in detail. The X-ray diffraction data revealed that a pure mayenite phase can be obtained for 0 ≤ x ≤ 7, whereas when x > 7, the samples crystallize into a melilite-like orthorhombic Ca5Ga6O14-based phase. The electrical conduction studies evidence no apparent enhancement in the total conductivity for compositions 0 ≤ x ≤ 7 with the mayenite phase, and therefore, the rigidity of the framework cations and the width of the windows between cages are not key factors for oxide-ion conductivity in mayenite Ca12Al14O33-based materials, and changing the free oxygen content through aliovalent cation substitution may be the right direction. For compositions with a pure melilite-like orthorhombic phase, the conductivities also mirrored each other and are all slightly higher than those of the mayenite phases. These melilite-like Ca5Ga6O14-based materials show mixed Ca-ion, oxide-ion, and electron conduction. Furthermore, the conduction mechanisms of Ca ions and oxide ions in this composition were studied by a bond-valence-based method. The results suggested that Ca-ion conduction is mainly due to the severely underbonded Ca3 ions and that the oxide ions are most likely transported via oxygen vacancies.
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Affiliation(s)
- Yun Lv
- MOE Key Laboratory of New Processing Technology for Nonferrous Metal and Materials, Guangxi Universities Key Laboratory of Non-ferrous Metal Oxide Electronic Functional Materials and Devices, College of Materials Science and Engineering, Guilin University of Technology, Guilin 541004, P. R. China
| | - Yanming Sun
- MOE Key Laboratory of New Processing Technology for Nonferrous Metal and Materials, Guangxi Universities Key Laboratory of Non-ferrous Metal Oxide Electronic Functional Materials and Devices, College of Materials Science and Engineering, Guilin University of Technology, Guilin 541004, P. R. China
| | - Jungu Xu
- MOE Key Laboratory of New Processing Technology for Nonferrous Metal and Materials, Guangxi Universities Key Laboratory of Non-ferrous Metal Oxide Electronic Functional Materials and Devices, College of Materials Science and Engineering, Guilin University of Technology, Guilin 541004, P. R. China
| | - Xiangyu Xu
- MOE Key Laboratory of New Processing Technology for Nonferrous Metal and Materials, Guangxi Universities Key Laboratory of Non-ferrous Metal Oxide Electronic Functional Materials and Devices, College of Materials Science and Engineering, Guilin University of Technology, Guilin 541004, P. R. China
| | - Alberto J Fernández-Carrión
- MOE Key Laboratory of New Processing Technology for Nonferrous Metal and Materials, Guangxi Universities Key Laboratory of Non-ferrous Metal Oxide Electronic Functional Materials and Devices, College of Materials Science and Engineering, Guilin University of Technology, Guilin 541004, P. R. China
| | - Tianjie Wei
- MOE Key Laboratory of New Processing Technology for Nonferrous Metal and Materials, Guangxi Universities Key Laboratory of Non-ferrous Metal Oxide Electronic Functional Materials and Devices, College of Materials Science and Engineering, Guilin University of Technology, Guilin 541004, P. R. China
| | - Huaibo Yi
- MOE Key Laboratory of New Processing Technology for Nonferrous Metal and Materials, Guangxi Universities Key Laboratory of Non-ferrous Metal Oxide Electronic Functional Materials and Devices, College of Materials Science and Engineering, Guilin University of Technology, Guilin 541004, P. R. China
| | - Xiaojun Kuang
- MOE Key Laboratory of New Processing Technology for Nonferrous Metal and Materials, Guangxi Universities Key Laboratory of Non-ferrous Metal Oxide Electronic Functional Materials and Devices, College of Materials Science and Engineering, Guilin University of Technology, Guilin 541004, P. R. China
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Yang X, Fernández-Carrión AJ, Wang J, Porcher F, Fayon F, Allix M, Kuang X. Cooperative mechanisms of oxygen vacancy stabilization and migration in the isolated tetrahedral anion Scheelite structure. Nat Commun 2018; 9:4484. [PMID: 30367043 PMCID: PMC6203716 DOI: 10.1038/s41467-018-06911-w] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 10/07/2018] [Indexed: 11/30/2022] Open
Abstract
Tetrahedral units can transport oxide anions via interstitial or vacancy defects owing to their great deformation and rotation flexibility. Compared with interstitial defects, vacancy-mediated oxide-ion conduction in tetrahedra-based structures is more difficult and occurs rarely. The isolated tetrahedral anion Scheelite structure has showed the advantage of conducting oxygen interstitials but oxygen vacancies can hardly be introduced into Scheelite to promote the oxide ion migration. Here we demonstrate that oxygen vacancies can be stabilized in the BiVO4 Scheelite structure through Sr2+ for Bi3+ substitution, leading to corner-sharing V2O7 tetrahedral dimers, and migrate via a cooperative mechanism involving V2O7-dimer breaking and reforming assisted by synergic rotation and deformation of neighboring VO4 tetrahedra. This finding reveals the ability of Scheelite structure to transport oxide ion through vacancies or interstitials, emphasizing the possibility to develop oxide-ion conductors with parallel vacancy and interstitial doping strategies within the same tetrahedra-based structure type. Fast oxide ion conductors are the key materials for some technological devices. Here the authors report the creation and stabilization of oxygen vacancies in BiVO4 Scheelite with isolated tetrahedral anion structures for improved ionic conducting performance and understanding of the conduction mechanism.
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Affiliation(s)
- Xiaoyan Yang
- MOE Key Laboratory of New Processing Technology for Nonferrous Metals and Materials, Guangxi University Key Laboratory of Nonferrous Metal Oxide Electronic Functional Materials and Devices, College of Materials Science and Engineering, Guilin University of Technology, Guilin, Guangxi, 541004, People's Republic of China
| | | | - Jiehua Wang
- MOE Key Laboratory of New Processing Technology for Nonferrous Metals and Materials, Guangxi University Key Laboratory of Nonferrous Metal Oxide Electronic Functional Materials and Devices, College of Materials Science and Engineering, Guilin University of Technology, Guilin, Guangxi, 541004, People's Republic of China
| | - Florence Porcher
- Laboratoire Léon Brillouin, CEA Saclay, 91191, Gif Sur Yvette, France
| | - Franck Fayon
- CNRS, CEMHTI UPR3079, Univ. Orléans, 45071, Orléans, France
| | - Mathieu Allix
- CNRS, CEMHTI UPR3079, Univ. Orléans, 45071, Orléans, France.
| | - Xiaojun Kuang
- MOE Key Laboratory of New Processing Technology for Nonferrous Metals and Materials, Guangxi University Key Laboratory of Nonferrous Metal Oxide Electronic Functional Materials and Devices, College of Materials Science and Engineering, Guilin University of Technology, Guilin, Guangxi, 541004, People's Republic of China.
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