Hollow MoSe₂/N-doped carbon composited with ZnIn₂S₄ constructing dual Z-scheme heterojunction for enhanced...

The hollow MoSe₂/N-doped carbon (NC) composite, which was obtained through Mo-polydopamine as a self-sacrificing template based on the Kirkendall effect, was further utilized to fabricate a novel ternary MoSe₂/NC/ZIS (MNZ) dual Z-scheme heterojunction by growing ZnIn₂S₄ (ZIS) onto it via a hydrothermal process. The optimized MNZ (12MNZ) heterojunction exhibits exceptional performance in photocatalytic degradation of tetracycline hydrochloride (TCH), hydrogen (H₂) evolution, hydrogen peroxide (H₂O₂) production, and carbon dioxide (CO₂) reduction under visible light irradiation. The 12MNZ photocatalyst achieves a significant photodegradation efficiency of TCH reaching 98.2 % in 30 min, and the rate constant k of the 12MNZ photocatalyst, which is 0.139 min^-1, is approximately 9.8 times greater than that of ZIS. The optimal photocatalytic H₂ evolution rate of 10,309 μmol g^-1 h^-1 achieved is 26.9 times greater than that of ZIS, while the superior production rate of H₂O₂ reaches 735.2 μmol L^-1 h^-1. Besides, the 12MNZ composite reveals the CO yield of 78.03 μmol g^-1 h^-1 with high selectivity of 95 %. The presence of a hollow structure and two built-in electric fields within the MNZ dual Z-scheme heterojunction significantly enhances the absorption efficiency of incident light and promotes the efficient migration of photogenerated carriers. The possible photocatalytic mechanism of the MNZ photocatalyst was presented through experimental measurements and density functional theory calculations. This work provides a promising strategy for developing highly efficient hollow dual Z-scheme heterojunction photocatalysts, aimed at enhancing environmental remediation and generating green energy.