Modification of the surface of Mn0.25Cd0.75S polyhedra with NiB: reducing the surface work function and promoting electron migration for enhanced photocatalytic hydrogen production

Abstract

Photocatalytic hydrogen production is one of the strategies to meet energy demand. Catalysts and cocatalysts used to produce H₂ are usually made of precious metals, which limits their further development. It is necessary to find efficient and low-cost non-noble metal catalysts and cocatalysts. Mn_0.25Cd_0.75S was synthesized by a hydrothermal method and as a composite with amorphous nickel boride nanomaterial. Hydrogen production over the NiB/Mn_0.25Cd_0.75S composites with different ratios under visible light was studied. The results showed that the photocatalytic effect of 10% NiB was the best, which was 13.06 mmol g⁻¹ h⁻¹, 3.7 times that of pure Mn_0.25Cd_0.75S. The enhancement mechanism is that the Mn_0.25Cd_0.75S composite has a close contact interface with NiB, which is favorable for the separation of photocarriers and provides more catalytic active centers. The composite material has good visible light absorption ability and efficient charge separation ability. The results show that transition metal borides can be used as a highly efficient cocatalyst, which can significantly improve the photocatalytic performance of semiconductor materials, providing a new idea for replacing noble metal catalysts.