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DOI	10.1073/pnas.2023552118
	A coating strategy to achieve effective local charge separation for photocatalytic coevolution
	Zhao T.; Yanagi R.; Xu Y.; He Y.; Song Y.; Yang M.; Hu S.
发表日期	2021
ISSN	00278424
卷号	118 期号:7
英文摘要	Semiconductors of narrow bandgaps and high quantum efficiency have not been broadly utilized for photocatalytic coevolution of H2 and O2 via water splitting. One prominent issue is to develop effective protection strategies, which not only mitigate photocorrosion in an aqueous environment but also facilitate charge separation. Achieving local charge separation is especially challenging when these reductive and oxidative sites are placed only nanometers apart compared to two macroscopically separated electrodes in a photoelectrochemical cell. Additionally, the driving force of charge separation, namely the energetic difference in the barrier heights across the two type of sites, is small. Herein, we used conformal coatings attached by nanoscale cocatalysts to transform two classes of tunable bandgap semiconductors, i.e., CdS and GaInP2, into stable and efficient photocatalysts. We used hydrogen evolution and redox-mediator oxidation for model study, and further constructed a two-compartment solar fuel generator that separated stoichiometric H2 and O2 products. Distinct from the single charge-transfer direction reported for conventional protective coatings, the coating herein allows for concurrent injection of photoexcited electrons and holes through the coating. The energetic difference between reductive and oxidative catalytic sites was regulated by selectivity and local kinetics. Accordingly, the charge separation behavior was validated using numerical simulations. Following this design principle, the CdS/TiO2/Rh@CrOx photocatalysts evolved H2 while oxidizing reversible polysulfide redox mediators at a maximum rate of 90.6 μmol·h−1·cm−2 by stacking three panels. Powered by a solar cell, the redox-mediated solar water-splitting reactor regenerated the polysulfide repeatedly and achieved solar-to-hydrogen efficiency of 1.7%. © 2021 National Academy of Sciences. All rights reserved.
英文关键词	Charge separation; Coatings; Corrosion protection; Photocatalytic synthesis; Reactor engineering
语种	英语
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/180622
作者单位	Department of Chemical and Environmental Engineering, Yale University, New Haven, CT 06520, United States; Energy Sciences Institute, Yale University, West Haven, CT 06516, United States
推荐引用方式 GB/T 7714	Zhao T.,Yanagi R.,Xu Y.,et al. A coating strategy to achieve effective local charge separation for photocatalytic coevolution[J],2021,118(7).
APA	Zhao T..,Yanagi R..,Xu Y..,He Y..,Song Y..,...&Hu S..(2021).A coating strategy to achieve effective local charge separation for photocatalytic coevolution.Proceedings of the National Academy of Sciences of the United States of America,118(7).
MLA	Zhao T.,et al."A coating strategy to achieve effective local charge separation for photocatalytic coevolution".Proceedings of the National Academy of Sciences of the United States of America 118.7(2021).