Perovskite oxynitride solid solutions of LaTaON2-CaTaO2N with greatly enhanced photogenerated charge separation for solar-driven overall water splitting
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The search for solar‐driven photocatalysts for overall water splitting has been actively pursued. Although metal oxynitrides with metal d0/d10‐closed shell configuration are very promising candidates in terms of their visible light absorption, they usually suffer from serious photo‐generated charge recombination and thus, little photoactivity. Here, by forming their solid solutions of LaTaON2 and CaTaO2N, which are traditionally considered to be inorganic yellow‐red pigments but have poor photocatalytic activity, a class of promising solar‐driven photocatalysts La1‐xCaxTaO1+yN2‐y (0 ≤ x, y ≤ 1) are explored. In particular, the optimal photocatalyst with x = 0.9 has the ability of realizing overall water splitting with stoichiometric H2/O2 ratio under the illumination of both AM1.5 simulated solar light and visible light. The modulated key parameters including band structure, Ta bonding environment, defects concentration, and band edge alignments revealed in La0.1Ca0.9TaO1+yN2‐y have substantially promoted the separation of photogenerated charge carriers with sufficient energetics for water oxidation and reduction reactions. The results obtained in this study provide an important candidate for designing efficient solar‐driven photocatalysts for overall water splitting.
Wang , Y , Kang , Y , Zhu , H , Liu , G , Irvine , J T S & Xu , X 2020 , ' Perovskite oxynitride solid solutions of LaTaON 2 -CaTaO 2 N with greatly enhanced photogenerated charge separation for solar-driven overall water splitting ' , Advanced Science , vol. Early View , 2003343 . https://doi.org/10.1002/advs.202003343
Copyright © 2020 The Authors. Published by Wiley‐VCH GmbH. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
DescriptionThe authors would like to thank the National Natural Science Foundation of China (Grant No. 51972233, 51825204, 21633009) and Natural Science Foundation of Shanghai (Grant No. 19ZR1459200) for funding. The work was supported by Shanghai Science and Technology Commission (14DZ2261100) and the Fundamental Research Funds for the Central Universities. G.L. thanks Newton Advanced Fellowship.
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