Directional electron transfer in ZnIn₂S₄/Mo₂TiC₂-Ru for efficient photocatalytic hydrogen evolution

A directional photogenerated electron transfer channel from ZnIn 2 S 4 to Mo 2 TiC 2 -Ru was formed in ZnIn 2 S 4 /Mo 2 TiC 2 -Ru. • The interface electronic delocalization effect between Ru nanoclusters and Mo 2 TiC 2 synergistically optimizes the water dissociation and hydrogen evolution sites. • ZnIn 2 S 4 /Mo 2 TiC 2 -Ru exhibits excellent photocatalytic hydrogen evolution activity under both visible light and natural light conditions. The photocatalytic hydrogen evolution (PHE) rate on ZnIn 2 S 4 is severely limited by the low utilization of photogenerated electrons and the sluggish reaction kinetics. Driving the directional transfer of photogenerated electrons to the target site is crucial for enhancing the electron utilization efficiency and the PHE performance. Herein, this study rationally designed a ternary composite photocatalyst ZnIn 2 S 4 /Mo 2 TiC 2 -Ru C , in which Mo 2 TiC 2 -Ru C serves as an electron acceptor and efficient active site. The in-situ KPFM and Mott-Schottky results indicate that the establishment of interfacial electron transport channel accelerates the transfer of photogenerated electrons from ZnIn 2 S 4 to Mo 2 TiC 2 . Density functional theory (DFT) calculations verify the strong metal-support interaction (EMSI) and interfacial electron delocalization of Mo 2 TiC 2 -Ru C , which synergistically optimize the water dissociation at Ru nanocluster and the hydrogen evolution desorption at the Mo 2 TiC 2 terminal, promoting the efficient utilization of photogenerated electrons. Therefore, ZnIn 2 S 4 /Mo 2 TiC 2 -Ru C achieved a PHE rate of 6.15 mmol·g −1 ·h −1 under visible light, and demonstrated excellent potential for PHE application under natural light. This study provides a new paradigm for integrating electron transfer dynamics with active site engineering to improve the utilization efficiency of photogenerated electrons in the photocatalytic hydrogen evolution process. Download: Download high-res image (350KB) Download: Download full-size image