Harnessing Hydrogen Spillover by Lattice Strain for Enhanced Photocatalytic Hydrogen Evolution of ZnIn₂S₄

Hydrogen spillover has been believed to play an essential role in the reaction path in photocatalysis, yet its rational regulation remains a considerable challenge for the design of highly efficient photocatalysts. Herein, hydrogen spillover can be well regulated at ZnIn₂S₄ with surface decorated by cubic α-MoC_1-x quantum dots (QDs) with different lattice strain (ZIS/QDs). With the increasing lattice strain of α-MoC_1-x, the composite shows first increased and then decreased photocatalytic hydrogen evolution (PHE). Spectroscopic characterizations and calculation analysis indicate that PHE performance of ZIS/QDs is highly corelated with hydrogen spillover rather than charge transfer process. Further systematic investigations suggest that compressive lattice strain uplifts the Fermi level of α-MoC_1-x and optimizes the interfacial spillover barrier between α-MoC_1-x and ZnIn₂S₄, achieving well-manipulated hydrogen spillover and enhanced PHE performance. This work demonstrates a general design from the perspective of lattice strain to harness hydrogen spillover effect in heterogeneous interface for hydrogen generation.