Y1‿i>xScxBaZn3GaO7 (0 ≿x ≿1): Structure Evolution by Sc-Doping and the First Example of Photocatalytic Water Reduction in ‿14‿Oxides

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• 作者：Xiaolong Li ; Pengfei Jiang ; Mufei Yue ; Rihong Cong ; Wenliang Gao ; Tao Yang
• 刊名：Inorganic Chemistry
• 出版年：2016
• 出版时间：February 15, 2016
• 年：2016
• 卷：55
• 期：4
• 页码：1527-1534
• 全文大小：641K
• ISSN：1520-510X

文摘

“114” oxides have shown intriguing physical properties while their performance in photocatalysis has not yet been reported probably due to the instability in aqueous solution. YBaZn₃GaO₇ is an exception, which is stable and indeed shows observable photocatalytic H₂ evolution (∼2 μmol/h/g) in methanol aqueous solution under UV light. This activity was enhanced to 23.6 μmol/h/g by a full replacement of Y³⁺ by Sc³⁺. Optical absorption spectra and theoretical calculations show no significant difference upon Sc³⁺-doping. Instead, a systematic analysis of the structure evolution by Rietveld refinements for Y_1–xSc_xBaZn₃GaO₇ (0 ≤ x ≤ 1) suggests that the increase of the catalytic activity is likely due to the decrease of the structural defects and thus the lower level of recombination rate of e^– and h⁺. In detail, Sc³⁺ substitution leads to a shrinkage of YO₆ octahedra, and successively the adjustment of the Zn²⁺/Ga³⁺ occupancy behaviors in tetrahedra sites. The photocatalytic H₂ evolution rate was further optimized to 118.2 μmol/h/g in methanol solution and 42.9 μmol/h/g in pure water for 1 wt % Pt-loaded ScBaZn₃GaO₇. Here, the relatively less investigated nonmagnetic “114” oxides were, for the first time, proved to be good candidates for photocatalytic water reduction.