In situ Mo doping in NiS2: enhancing electron density and stimulating electronic conductivity of Cu3P–GDY for efficient photocatalytic hydrogen evolution

Abstract

The electronic conductivity of a catalyst can be enhanced by strategically doping with specific elements. In this study, a Mo_0.1NiS₂/Cu₃P–GDY composite photocatalyst featuring a hierarchical structure was meticulously designed, optimizing the charge migration path to boost electronic conductivity. The in situ doping of molybdenum (Mo) induced a Burstein–Moss effect, effectively enhancing the electronic conductivity and electron density of NiS₂. The Mo_0.1NiS₂ component was paired with a co-catalyst that further stimulated the electronic conductivity of Cu₃P–GDY and expedited electron transport. The findings revealed that the hydrogen evolution capacity of the composite catalyst was 2.9 and 4.7 times greater than those of Mo_0.1NiS₂ and Cu₃P–GDY, respectively, reaching 133.1 μmol g⁻¹. In situ X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations confirmed the formation of an S-scheme heterojunction between the catalysts, establishing a directional charge transfer pathway that significantly improves the charge transfer rate and, consequently, the hydrogen evolution activity of the composite photocatalyst. This research provides a valuable design strategy for enhancing the hydrogen evolution activity of photocatalysts by increasing electronic conductivity.