Tailoring Charge Separation in ZnIn₂S₄@CdS Hollow Nanocages for Simultaneous Alcohol Oxidation and CO₂ Reduction under Visible Light

Abstract

Artificial photosynthesis provides a sustainable strategy for producing usable fuels and fine chemicals and attracts broad research interest. However, conventional approaches suffer from low reactivity or low selectivity. Herein, we demonstrate that photocatalytic reduction of CO 2 coupled with selective oxidation of aromatic alcohol into corresponding syngas and aromatic aldehydes can be processed efficiently and fantastically over the designed S-scheme ZnIn 2 S 4 @CdS core−shell hollow nanocage under visible light. In the ZnIn 2 S 4 @CdS heterostructure, the photoexcited electrons and holes with weak redox capacities are eliminated, while the photoexcited electrons and holes with powder redox capacities are separated spatially and preserved on the desired active sites. Therefore, even if there are no cocatalysts and no vacancies, ZnIn 2 S 4 @CdS exhibits high reactivity. For instance, the CO production of ZnIn 2 S 4 @CdS is about 3.2 and 3.4 times higher than that of pure CdS and ZnIn 2 S 4 , respectively. More importantly, ZnIn 2 S 4 @CdS exhibits general applicability and high photocatalytic stability. Trapping agent experiments, 13 CO 2 isotopic tracing, in situ characterizations, and theoretical calculations reveal the photocatalytic mechanism. This study provides a new strategy to design efficient and selective photocatalysts for dual-function redox reactions by tailoring the active sites and regulating vector separation of photoexcited charge carriers.