POM-incorporated ZnIn2S4 Z-scheme dual-functional photocatalysts for cooperative benzyl alcohol oxidation and H2 evolution in aqueous solution

Abstract

Efficient aromatic alcohol oxidation with simultaneous H2 evolution under aqueous conditions is achieved in a polyoxometalate (POM)-incorporated ZnIn2S4 dual-functional photocatalytic system. The synergy between HPM and ZIS contributes to the formation of a Z-type heterojunction structure and thus enhances redox capacity. Moreover, the sub-nanometer size of POM clusters endows molecular-level interfacial contact, which acts as an "electron bridge" ensuring faster interfacial charge transfer kinetics. Therefore, an impressive nearly 100% yield of benzaldehyde and 10.6 mmol·g−1·h−1 H2-evolution rate are observed for POM/ZIS nanocomposites even under an anaerobic atmosphere with water as the solvent. This is the first application of POM-based materials in the anaerobic oxidation of benzyl alcohol with concomitant H2 production. This study expands the possibilities for designing multifunctional POM-based photocatalysts for economic and ecological photoredox applications.