Surface Energy Mediated Sulfur Vacancy of ZnIn2S4 Atomic Layers for Photocatalytic H2O2 Production

Constructing rich defect active site structure for material design is still a great challenge. Herein, a simple surface engineering strategy is demonstrated to construct one-unit-cell ZnIn2S4 atomic layers with the modulated surface energy of S vacancy. Rich surface energy can regulate and control the rich S vacancy, which ensures rich active sites, higher charge density and effective carrier transport. As a result, the ZnIn2S4 atomic layers with rich surface energy affords an obvious enhancement in H2O2 productive rate of 1592.04 mu mol g(-1) h(-1), roughly 14.58 times superior to that with poor surface energy. Moreover, the in situ infrared diffuse reflection spectrum indicates that S vacancy as the oxygen reduction reaction active site is responsible for the critical intermediate *O-2(-) and *OOH, corresponding to two-electron oxygen reduction reaction. This study provides a valuable insight and guidance for constructing controllably defects to achieve highly efficient H2O2 production.