Enhancing the efficiency of the photocatalytic hydrogen evolution half-reaction via disruption of the rigid H-bond network at the RuS2/ZnCdS interface

Abstract

Understanding the evolution of the H-bond network at the catalyst−water interface is fundamental to the water photolysis half-reaction for hydrogen evolution. This work investigates the reaction mechanism of RuS₂ cluster-loaded ZnCdS (ZCS) composite catalysts for photocatalytic hydrogen evolution (PHE) from the perspective of catalyst design and interfacial H-bond networks. The optimized 7.5RS/ZCS catalyst achieves a remarkable PHE rate of 77.2 mmol g⁻¹ h⁻¹ in a 10 vol% lactic acid solution, representing a 154-fold enhancement over pristine ZCS. Combined DFT calculations, molecular dynamics simulations, and H₂O-TPD analysis demonstrate that RuS₂ serves as a highly efficient dual-active center, which not only facilitates water adsorption but also promotes its dissociation. More importantly, RuS₂ disrupts the interfacial H-bond network and optimizes the configuration of water molecules at the interface. These synergistic effects substantially enhance the PHE performance of the 7.5RS/ZCS composite. This work provides new insights into the role of interfacial water structures in PHE and offers an effective interfacial engineering strategy for designing advanced photocatalysts.