Vacancy-defect modulated pathway of photoreduction of CO2 on single atomically thin AgInP2S6 sheets into olefiant gas
Wa Gao, Li Shi, Huichao He, Xiaoning Li, Zhenxiang Cheng, Yong Yang, Jinlan Wang, Qing Shen, Xiaoyong Wang, Yujie Xiong, Yong Zhou, Zhigang Zou
Abstract
Abstract Artificial photosynthesis, light-driving CO 2 conversion into hydrocarbon fuels, is a promising strategy to synchronously overcome global warming and energy-supply issues. The quaternary AgInP 2 S 6 atomic layer with the thickness of ~ 0.70 nm were successfully synthesized through facile ultrasonic exfoliation of the corresponding bulk crystal. The sulfur defect engineering on this atomic layer through a H 2 O 2 etching treatment can excitingly change the CO 2 photoreduction reaction pathway to steer dominant generation of ethene with the yield-based selectivity reaching ~73% and the electron-based selectivity as high as ~89%. Both DFT calculation and in-situ FTIR spectra demonstrate that as the introduction of S vacancies in AgInP 2 S 6 causes the charge accumulation on the Ag atoms near the S vacancies, the exposed Ag sites can thus effectively capture the forming *CO molecules. It makes the catalyst surface enrich with key reaction intermediates to lower the C-C binding coupling barrier, which facilitates the production of ethene.