Modulating charge centers and vacancies in P-CoNi loaded phosphorus-doped ZnIn2S4 nanosheets for H2 and H2O2 photosynthesis from pure water

Abstract

Photocatalytic water splitting has recently attracted increasing interests for solar to chemical energy conversion. Nevertheless, the high-efficiency process for photocatalytic water splitting is driven by recombination of photogenerated electron-hole pairs and the resultant low H2 productivity. Herein, we demonstrate that P-doping induced positive charge centers (Pδ+) and indium vacancies (VIn) in ZnIn2S4 (ZIS) nanosheets can significantly promote photosplitting pure water to simultaneously produce H2 and H2O2. Microstructural and spectroscopic analysis suggest that Pδ+ and VIn can trap photogenerated electrons and holes, respectively, as a result of enhanced separation of electron-hole pairs. The optimal catalyst of P-CoNi/ZIS displays a stoichiometric H2 and H2O2 productivity of 1228.7 and 1105.5 μmol h−1 g−1, respectively, with an apparent quantum efficiency of 6.2% at 365 nm. Impressively, H2 productivity of P-CoNi/ZIS has surpassed most reported catalysts for photocatalytic pure water splitting. This work provides a unique strategy to create efficient photocatalyst for pure water splitting.