Reasonably design of hollow spherical g-C3N4/Mn0.25Cd0.75S heterojunction for efficient photocatalytic hydrogen production and tetracycline degradation

Developing efficient catalysts for photocatalytic hydrogen evolution and pollutant degradation is one of the most ideal methods to address energy and environmental pollution issues. To address the challenges of energy crisis and environmental issues, a hollow spherical g-C3N4/Mn0.25Cd0.75S (HCNS/MCS) heterostructure was constructed and characterized. The unique morphology and appropriate band gap of the hollow carbon nitride sphere (HCNS) make it a promising photocatalytic material. The growth of Mn0.25Cd0.75S solid solution on HCNS enhances the spatial separation of photo-generated charges at the HCNS/MCS interface, thereby promoting electron transfer and reaction kinetics. Under visible light irradiation, the HCNS/MCS exhibited the highest H2 production activity (31.34 mmol·g-1·h-1), which was 2.8 times that of pure MCS and 224 times that of pure HCNS. Moreover, the HCNS/MCS photocatalyst achieved a removal rate of 94% for tetracycline within 180 min under visible light, involving the •OH and •O2- radicals and following the proposed type-Ⅱ mechanism. This work contributes to the design of highly efficient photocatalytic materials with synergistic effects for photocatalytic hydrogen evolution and organic pollutant degradation.