MoP@MoO3 S-scheme heterojunction in situ construction with phosphating MoO3 for high-efficient photocatalytic hydrogen production

Abstract

As important artificial photosynthesis, the construction of core–shell heterojunction materials is considered to be one of the effective strategies for designing highly active photocatalysts. Here, the Step-scheme (S-scheme) heterojunction photocatalyst is firmly grown by in situ phosphating. The calcination method uses MoO₃ nanoparticles as the substrate, and the surface of MoO₃ is phosphatized and etched gradually from the outside to the inside using the phosphine gas. The introduced phosphorus atoms can replace MoO₃ oxygen atoms to form Mo–P bonds to generate molybdenum phosphide. The interface interaction dominated by chemical bonds has a stronger interface interaction force, which can promote the interface charge transfer leading to optimizing the MoP@MoO₃ core–shell composite material, adjusting the quality of sodium hypophosphite, and phosphating MoO₃ to varying degrees, producing the best hydrogen production H₂ evolution rate is 10 000.02 μmol h⁻¹ g⁻¹. Density functional theory (DFT) calculations and a series of experiments were used to determine the S-scheme charge transfer mechanism in MoP@MoO₃. This design provides a new idea for the introduction of surface-active sites and the construction of mixed anion photocatalysts. At the same time, a new design scheme is provided for the in situ construction of S-scheme interface heterojunction materials.