Defective ZnIn 2 S 4 Nanosheets for Visible-Light and Sacrificial-Agent-Free H 2 O 2 Photosynthesis via O 2 /H 2 O Redox

• Published in: Journal of the American Chemical Society Vol. 145; no. 50; pp. 27757 - 27766
• Main Authors: Peng, Huiping, Yang, Hongcen, Han, Jiajia, Liu, Xiaozhi, Su, Dong, Yang, Tang, Liu, Shangheng, Pao, Chih-Wen, Hu, Zhiwei, Zhang, Qiaobao, Xu, Yong, Geng, Hongbo, Huang, Xiaoqing
• Format: Journal Article
• Language: English
• Published: United States 20-12-2023
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/jacs.3c10390

H
O
photosynthesis has attracted great interest in harvesting and converting solar energy to chemical energy. Nevertheless, the high-efficiency process of H
O
photosynthesis is driven by the low H
O
productivity due to the recombination of photogenerated electron-hole pairs, especially in the absence of a sacrificial agent. In this work, we demonstrate that ultrathin ZnIn
S
nanosheets with S vacancies (S
-ZIS) can serve as highly efficient catalysts for H
O
photosynthesis via O
/H
O redox. Mechanism studies confirm that S
in ZIS can extend the lifetimes of photogenerated carriers and suppress their recombination, which triggers the O
reduction and H
O oxidation to H
O
through radical initiation. Theoretical calculations suggest that the formation of S
can strongly change the coordination structure of ZIS, modulating the adsorption abilities to intermediates and avoiding the overoxidation of H
O to O
during O
/H
O redox, synergistically promoting 2e
O
reduction and 2e
H
O oxidation for ultrahigh H
O
productivity. The optimal catalyst displays a H
O
productivity of 1706.4 μmol g
h
under visible-light irradiation without a sacrificial agent, which is ∼29 times higher than that of pristine ZIS (59.4 μmol g
h
) and even much higher than those of reported photocatalysts. Impressively, the apparent quantum efficiency is up to 9.9% at 420 nm, and the solar-to-chemical conversion efficiency reaches ∼0.81%, significantly higher than the value for natural synthetic plants (∼0.10%). This work provides a facile strategy to separate the photogenerated electron-hole pairs of ZIS for H
O
photosynthesis, which may promote fundamental research on solar energy harvest and conversion.