Benzyl alcohol oxidation and hydrogen generation over MoS2/ZnIn2S4 composite photocatalyst

Owing to the simultaneous utilization of photogenerated electrons and holes, coupling light-driven hydrogen (H2) evolution reaction (HER) and biomass-derived alcohol conversion reactions in one photoredox cycle has aroused many interests for the coproduction of valuable chemical products and renewable fuels. In this study, a facile photochemical reduction approach has been used to decorate MoS2 cocatalyst on ZnIn2S4 nanoflowers (NFs) for photocatalytic coupling reactions of selective benzyl alcohol (BA) oxidation and HER. The results reveal that 1%MoS2/ZnIn2S4 composite photocatalyst displays the best visible-light-induced photoactivity for BA conversion (3.69 mmol g−1 h−1) and H2 evolution (3.88 mmol g−1 h−1), exhibiting 6 times as high as the photoactivity over bare ZnIn2S4. The MoS2 cocatalyst markedly improves charge separation and mitigates the overpotential of HER, thereby accelerating H2 production kinetics for the coproduction reactions. The photoreduction of Cr (VI) and 4-nitroaniline (4-NA) is also investigated to verify the universality of MoS2 as high-performance cocatalyst. The carbon-centered radical is identified in BA conversion over MoS2/ZnIn2S4 composite photocatalyst. This work could contribute to the rational construction of ZnIn2S4-based cooperative photoredox-catalyzed system toward efficient coproduction of value-added fine chemicals and clean fuels.Graphical abstract