Modulating Interfacial Mo-S Chemical-Bond Enable Highly-Efficient Charge Transfer for Promoted Visible-light-driven Photocatalytic Hydrogen Evolution

Non-precious metal cocatalysts and interfacial charge transfer dynamics have long been recognized as critical research frontiers in photocatalytic hydrogen production via water splitting. In this study, we demonstrate a highly efficient Mo 2 C/CdS composite photocatalyst, where the construction of Mo-S chemical bonds significantly enhances interfacial charge transfer. Mo 2 C, as an effective non-noble metal cocatalyst, facilitates the efficient acceptance of photogenerated electrons from CdS. The formation of Mo-S bonds substantially boosts the hydrogen evolution activity. Remarkably, the optimized 7   wt% Mo 2 C/CdS composite achieves a photocatalytic hydrogen production rate of 19.94   mmol   h -1 g -1 , representing a 51-fold enhancement compared to pristine CdS (0.39   mmol   h -1 g -1 ). Furthermore, this hydrogen evolution rate surpasses that of the Pt/CdS composite by 296%. Synchrotron radiation analysis provides direct evidence for the formation of Mo-S chemical bonds at the interface. Additionally, DFT calculations reveal that the Gibbs free energy change for hydrogen adsorption on Mo 2 C/CdS is reduced by -0.23   eV, further confirming the favorable thermodynamics for hydrogen generation. This study not only validates Mo 2 C as a promising cocatalyst but also highlights its potential to replace the benchmark Pt in photocatalytic water splitting. The findings offer valuable insights by intentionally constructing interfacial chemical bonds to accelerate charge transfer and significantly enhance photocatalytic performance.