文献类型：期刊文献

英文题名：Boosted Charge Separation in Core@Shell N-Ta2O5@α-Fe2O3 Heterojunctions via Band Structure Engineering for Enhanced Visible-Light-Driven Photoelectrocatalytic Water Oxidation

作者：Liu, Yaqiao[1]; Hu, Shuozhen[1]; Gao, Zhaoqun[1]; Zhang, Xinsheng[1]; Sun, Shigang[2]

机构：[1] State Key Laboratory of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, Shanghai, 200237, China; [2] State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China

年份：2023

卷号：6

期号：18

起止页码：9672

外文期刊名：ACS Applied Energy Materials

收录：EI(收录号：20234414984554)

语种：英文

外文关键词：Band structure - Chemical stability - Doping (additives) - Fermi level - Heat treatment - Hematite - Heterojunctions - Nanorods - Oxidation - Oxygen vacancies - Photoelectrochemical cells - Solar fuels - Tantalum oxides

摘要：Photoelectrochemical (PEC) water oxidation is considered to be a promising approach to converting solar energy into clean chemical fuels. α-Fe2O3 is a potential photoanode material for water oxidation with a high theoretical photocurrent density (12.6 mA cm-2) driven by visible light. Constructing α-Fe2O3-based heterojunction with other semiconductors is a promising strategy to improve the actual photoelectrocatalytic activity. In this work, nitrogen-doped Ta2O5 is introduced to synthesize N-Ta2O5-h@α-Fe2O3 nanorod heterojunction with different band structures. At the interface, electrons transfer from N-Ta2O5-h to α-Fe2O3, which forms a built-in electric field. The heterojunction structure contributes to inhibiting the severe recombination of photogenerated electron-hole pairs. By controlling the duration of mild heat treatment, the N-Ta2O5-h nanorods with different Fermi energy levels and contents of oxygen vacancies are obtained. A mild heat treatment in N2 is proved to enlarge the ΔE by leveling up the Fermi level and to promote the content of oxygen vacancies for the N-Ta2O5-h@α-Fe2O3 heterojunction as the heat-treatment time increases. The PEC water oxidation performance of the N-Ta2O5-h@α-Fe2O3 heterojunction increases when the mild-heat-treatment time is 2 h and decreases for 6 h treatment. Eventually, N-Ta2O5-2@α-Fe2O3 exhibits an enhanced photocurrent density of 3.10 mA cm-2 (4.4 times higher than that of bare α-Fe2O3), an efficiently boosted charge separation (2.0 times higher than bare α-Fe2O3), and a high chemical stability after a long-term test. ? 2023 American Chemical Society.