Inorganic Chemistry Frontiers
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2021
·Vol. 8
·期 15
·3723-3732
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IF 6.569
Yuwei Zhang,Xiaoxiang Xu
Solid solutions of LaTaON2 and BaTaO2N, i.e., La1−xBaxTaO1+yN2−y (0 ≤ x, y ≤ 1), have been investigated as visible-light-active photocatalysts for water oxidation reactions. A number of important parameters such as Ta–O/N distance, Ta–O/N–Ta angle, band gap and band edge alignments can be tailored by adjusting their solid solution levels, which in turn, effectively steer the photocatalytic behaviors. In particular, optimal photocatalytic activity for water oxidation can be achieved in the solid solution La0.2Ba0.8TaO1+yN2−y (x = 0.8), exhibiting an apparent quantum efficiency (AQE) as high as 3.91% at 420 ± 20 nm. This work signifies the usefulness of the solid solution strategy for ameliorating the photocatalytic properties of perovskite oxynitrides that can be well-extended to many other semiconductor photocatalysts.
研究领域:
材料科学
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化学
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产品关联
DOI
高影响因子
Energy Material Advances
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2022
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IF 0
Ying Luo,Qiaoqi Guo,Jun Xu,Hanghang Zhou,Zheng Wang,Hong He
BaTaO2N with intense visible light absorption has been demonstrated as a promising photocatalyst for Z-scheme overall water splitting, whereas the photocatalytic activity of BaTaO2N is still restricted by strong charge recombination at structural defects. Here, we present the direct growth of BaTaO2N–BaNa0.25Ta0.75O3 solid solution from a lattice-matched BaNa0.25Ta0.75O3 precursor through volatilization of Na species during a nitridation process. This method promotes the direct phase transformation from BaNa0.25Ta0.75O3 to BaTaO2N to inhibit the formation of defect states. As a result, the as-obtained BaTaO2N–BaNa0.25Ta0.75O3 solid solution shows greatly enhanced activity compared to the conventional BaTaO2N, regardless of photocatalytic H2 evolution in the presence of methanol or Z-scheme overall water splitting. This study provides a facile method to construct (oxy)nitride-based solid solution photocatalysts with low defect density for efficient solar hydrogen production from water splitting.
研究领域:
材料科学
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能源化学
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DOI
JOURNAL OF CATALYSIS
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2020
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IF 7.888
Hong Zhang,Shunhang Wei,Xiaoxiang Xu
BaTaO 2 N owns a promising band gap of 1.8 eV and suitable band edge positions but generally exhibits poor photocatalytic activity for water splitting reactions. In this work, we have modified BaTaO 2 N by introducing Mg to the B site of perovskite lattice to form a new compound, i.e. BaTa 0.95 Mg 0.05 O 2+x N 1−y . This modification results in an alteration to a number of important parameters such as unit cell size, nitrogen content, optical absorption and microstructures etc. More importantly, Mg modifications are responsible for stronger Ta-O/N bonds, lower Ta 4+ defects concentration and positively shift of band edge positions, which in turn contribute to high photocatalytic activities for water oxidation reactions. Apparent quantum efficiency as high as 2.59% has been realized at 420 ± 20 nm, being the highest for BaTaO 2 N reported to date under similar conditions. Further photoelectrochemical analysis confirms better charge utilizations in Mg modified BaTaO 2 N.
研究领域:
材料科学
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化学
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DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
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2024
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IF 4.7
Yixin Liu,Yanpei Luo,Beibei Dong
BaTaO 2 N (BTON) with a generous adsorption edge of ca. 660 nm and high theoretical solar-to-hydrogen conversion efficiency of ca. 20.6% has been extensively investigated for photocatalytic water splitting. In this study, we have successfully prepared a porous BTON nanosheet via employing Ba 2 Bi 3 Ta 2 O 11 Cl (BBTOC) oxyhalide as a novel nitridation precursor. The oxygen evolution rate of the BTON nanosheet is 108 μmol·h -1 , which is three times higher than that of BTON (25.9 μmol·h -1 ) prepared by conventional solid-state method. The successful construction of porous BTON nanosheet is due to the structural transformation of BBTOC nanosheet precursor and facile evaporation of Bi and Cl elements. The porous nanosheet morphology of BTON can not only promote the transfer of photogenerated charge carriers but also provide abundant reaction sites for the oxygen evolution reaction. This work demonstrates a novel and efficient strategy for preparing oxynitride for efficient solar energy conversion.
研究领域:
材料科学
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光催化
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能量转换
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DOI
高影响因子
CERAMICS INTERNATIONAL
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2018
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IF 3.057
Wen-Bin Niu,Shi-Kuan Sun,Wei-Ming Guo,Shan-Lu Chen,Ming Lv,Hua-Tay Lin,Cheng-Yong Wang
The perovskite-structure group oxynitrides BaTaO 2 N and SrNbO 2 N, usually obtained by ammonolysis of the oxide precursors, were prepared by the reaction between the corresponding alkaline earth carbonate and tantalum nitride or niobium nitride in the flow of nitrogen. The chemical composition and particle morphology of the products were investigated as well as the phase path and reaction mechanism. It was found that the nearly single phase oxynitride phases formed at 1200–1300 °C, where the partial oxidation of nitrides and the absence of oxide impurities was achievable. The products were deficient in nitrogen content and formed with a fine particle size with the narrow size distribution.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2018
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IF 11.698
Shunhang Wei,Guan Zhang,Xiaoxiang Xu
Despite a strong visible light absorbance as far as 660 nm, BaTaO 2 N generally exhibits a poor photocatalytic activity for water splitting under ordinary conditions. High levels of defects as well as photocatalytic self-decomposition are likely the major causes for this incommensuration. In this work, we have modified BaTaO 2 N by introducing Ca to the structure, i.e. BaCa x/3 Ta 1-x/3 O 2+y N 1-y (0 ≤ x, y ≤ 1). A number of important properties such as band gap, defects levels and nitrogen content can be tuned by varying the amounts of Ca in the structure. In particular, defects such as Ta 4+ species can be effectively suppressed by Ca incorporation. More importantly, photocatalytic activity for water oxidation has been significantly enhanced and stability against photocatalytic self-decomposition has also been largely improved in Ca modified BaTaO 2 N. An apparent quantum efficiency as high as ∼ 2.1% at 420 ± 20 nm has been achieved and stands as the highest AQE for BaTaO 2 N reported to date. Photoelectrochemical (PEC) analysis reveals a much higher photocurrent in Ca modified BaTaO 2 N and identifies the role of cocatalyst CoO z in reducing charge transfer resistance for water oxidation reactions. Open-circuit voltage decay (OCVD) measurements further confirm the improved charge separation conditions in Ca modified BaTaO 2 N and functions of cocatalyst CoO z in collecting and storing photo-generated holes. The optimal loading point for cocatalyst CoO z corresponds to the one that gives the highest capacity for hole storage.
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高影响因子
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