Sulfur Vacancy and Ti3C2Tx Cocatalyst Synergistically Boosting Interfacial Charge Transfer in 2D/2D Ti3C2Tx/ZnIn2S4 Heterostructure for Enhanced Photocatalytic Hydrogen Evolution

Abstract Constructing an efficient photoelectron transfer channel to promote the charge carrier separation is a great challenge for enhancing photocatalytic hydrogen evolution from water. In this work, an ultrathin 2D/2D Ti 3 C 2 T x /ZnIn 2 S 4 heterostructure is rationally designed by coupling the ultrathin ZnIn 2 S 4 with few‐layered Ti 3 C 2 T x via the electrostatic self‐assembly strategy. The 2D/2D Ti 3 C 2 T x /ZnIn 2 S 4 heterostructure possesses larger contact area and strong electronic interaction to promote the charge carrier transfer at the interface, and the sulfur vacancy on the ZnIn 2 S 4 acting as the electron trap further enhances the separation of the photoinduced electrons and holes. As a consequence, the optimal 2D/2D Ti 3 C 2 T x /ZnIn 2 S 4 composite exhibits a high photocatalytic hydrogen evolution rate of 148.4 µmol h −1 , which is 3.6 times and 9.2 times higher than that of ZnIn 2 S 4 nanosheet and flower‐like ZnIn 2 S 4 , respectively. Moreover, the stability of the ZnIn 2 S 4 is significantly improved after coupling with the few‐layered Ti 3 C 2 T x . The characterizations and density functional theory calculation demonstrate that the synergistic effect of the sulfur vacancy and Ti 3 C 2 T x cocatalyst can greatly promote the electrons transfer from ZnIn 2 S 4 to Ti 3 C 2 T x and the separation of photogenerated charge carriers, thus enhancing the photocatalytic hydrogen evolution from water.