Efficient spatial separation of charge carriers over CoS1+x cocatalyst modified MIL-88B (Fe)/ZnIn2S4 S-scheme heterojunctions for photoredox dual reaction and insight into the charge-transfer mechanism

The key to achieve an efficient cooperative photoredox reaction system is to elaborately construct high-efficiency multifunctional photocatalysts with the maximum carrier utilization. Herein, a well-design S-scheme MIL-88B (Fe)/ZIS heterojunction modified with amorphous CoS 1+x cocatalyst (CMZIS) was firstly successfully constructed. The CMZIS heterojunctions show a high H 2 evolution rate of 3164.9 μmol g −1 h −1 coupling with a benzaldehyde generation rate of 3417.8 μmol g −1 h −1 , which are 7.9 and 8.1 times higher than those of pure ZIS. The excellent performance of CMZIS heterojunctions benefits from the synergistic effect of S-Scheme heterojunction and CoS 1+x cocatalysts. This synergy realized the directional transfer and spatial separation of photogenerated carriers in CMZIS, thus inhibiting charge recombination and and maximizing the redox ability of charge carriers. Moreover, CoS 1+x cocatalyst offer more active sites and further enhance the H 2 evolution efficiency. This work will offer fresh insights to the construction and mechanism study of advanced multifunctional photocatalysts for the highly efficient cooperative photoredox reaction system.