Ni(OH) surface-modified hierarchical ZnInS nanosheets: dual photocatalytic application and mechanistic insights.

The simultaneous utilization of electrons and holes to couple photocatalytic H production with selective biomass transformation has attracted immense interest toward achieving sustainability in the fields of energy and chemical industry. In this study, by assembling highly dispersed Ni(OH) onto ZnInS (ZIS), efficient H evolution along with highly selective photocatalytic oxidation of furfuryl alcohol (FA) to furfural (FF) in pure water was achieved under anaerobic conditions. The H production and FA conversion rates over the optimal Ni-ZIS sample reached about 686 and 583 μmol g h, respectively, about 4.9 and 1.7 folds as those of pure ZIS. Moreover, the formation of by-products with C-C coupling was dramatically suppressed over Ni-ZIS, resulting in higher selectivity for FF (97%), which is about 2.7-fold that of pure ZIS (36%). Deep mechanistic studies were conducted to reveal the structural evolution and cocatalyst effects of Ni(OH). This study not only offers a feasible paradigm for modifying the surface of catalysts to tune the photoactivity and selectivity for product-oriented alcohol oxidation coupled with efficient H production in water but also reveals the working mechanism of the deposited Ni(OH) over ZIS toward coupling reactions.