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 ZnIn 2 S 4 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 ZnIn 2 S 4 atomic layers with rich surface energy affords an obvious enhancement in H 2 O 2 productive rate of 1592.04 µmol 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 H 2 O 2 production.