Dual MOF and CuInS2-Constructed Dual Z-Scheme Heterojunctions for Enhanced Photocatalytic Hydrogen Production and Methylene Blue Degradation

A novel dual Z-scheme heterojunction photocatalyst was constructed by introducing the narrow-bandgap semiconductor CuInS2(CIS) into the dual metal-organic framework (MOF) system of UiO-66(Zr) and NH2-MIL-101(Fe). This structure effectively overcomes the limitations of conventional photocatalysts in terms of light absorption range and the separation efficiency of photogenerated charge carriers. The prepared ternary catalyst, (UiO-66(Zr))-(NH2-MIL-101(Fe))/CuInS2, exhibited excellent photocatalytic performance under visible light irradiation, achieving a hydrogen production rate of 888 μmol g−1h−1and a methylene blue (MB) degradation efficiency of up to 95.03%. The significant enhancement in performance is attributed to the material’s porous structure, extended light absorption range, and optimized electron transfer pathways. Additionally, the construction of the dual Z-scheme heterojunction further promotes the separation and migration of photogenerated charge carriers, suppressing electron–hole recombination. This study demonstrates the great potential of dual Z-scheme heterojunctions in improving photocatalytic efficiency and provides an important theoretical foundation and design strategy for the development of efficient photocatalysts.