Cu-doped hollow tubular ZnIn2S4 using MIL-68-NH2 as templates for efficient photocatalytic synthesis of H2O2 in ambient air and pure water

Utilizing metal–organic frameworks as templates to synthesize photocatalysts has garnered increasing attention thanks to their substantial advantages. In this study, Cu-doped ZnIn 2 S 4 with hollow tubular structures was ingeniously synthesized using MIL-68-NH 2 as a template for photocatalytic H 2 O 2 production in ambient air and pure water under visible light. The hollow tubular structures promote light penetration and reflection, furnish substantial accessible reactive sites and accelerate the diffusion of reactants and products. Cu doping notably varies the band configuration of ZnIn 2 S 4 , resulting in a narrower bandgap and a lower conduction band potential. Their cooperative effects enable a respectable H 2 O 2 production from oxygen reduction reactions. The hollow tubular ZnIn 2 S 4 and corresponding Cu-doped counterpart achieved high H 2 O 2 yields of 1153 and 1616 μmol·L −1 , respectively, 3.6 and 5.1 times-increase compared with that of ordinary ZnIn 2 S 4 prepared without MIL-68-NH 2 . This work would provide a new perspective on ZnIn 2 S 4 -based photocatalysts and provoke the study on the green synthesis of H 2 O 2 .