Ni(OH) 2 surface-modified hierarchical ZnIn 2 S 4 nanosheets: dual photocatalytic application and mechanistic insights.

The simultaneous utilization of electrons and holes to couple photocatalytic H 2 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) 2 onto ZnIn 2 S 4 (ZIS), efficient H 2 evolution along with highly selective photocatalytic oxidation of furfuryl alcohol (FA) to furfural (FF) in pure water was achieved under anaerobic conditions. The H 2 production and FA conversion rates over the optimal Ni-ZIS sample reached about 686 and 583 μmol g -1 h -1 , 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) 2 . 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 2 production in water but also reveals the working mechanism of the deposited Ni(OH) 2 over ZIS toward coupling reactions.