Dual Z-Scheme MoS2/g-C3N4/Bi2O3 Composite Coating on Carbon Fiber with Enhanced Photocatalytic Performance

A double-layer core–shell photocatalytic coating was engineered on carbon fibers (CFb) derived from bamboo pulp precursors, employing a sequential process involving seed pre-loading, solvothermal treatment, and impregnation. XRD, SEM, and SEM-EDS analyses revealed that g-C3N4 and Bi2O3 nanosheets were co-assembled on the carbon fiber skeleton, and 50 nm MoS2 particles were successfully loaded, resulting in the fabrication of MoS2/g-C3N4/Bi2O3/CFb photocatalytic fibers. UV–vis spectroscopy, transient photocurrent response, and EIS tests demonstrated that the introduction of narrow-bandgap visible-light photocatalysts (g-C3N4 and MoS2) enhanced light absorption and improved the separation and migration efficiency of photogenerated electron hole pairs. Photocatalytic degradation experiments of MB showed that MoS2/g-C3N4/Bi2O3/CFb significantly outperformed g-C3N4/Bi2O3/CFb and Bi2O3/CFb, achieving a degradation efficiency of 92% within 60 min. Band structure calculations and analysis confirmed the formation of Z-scheme heterojunctions between g-C3N4 and Bi2O3, as well as between MoS2 and Bi2O3. This dual Z-scheme heterojunction endowed MoS2/g-C3N4/Bi2O3/CFb with enhanced redox capabilities, providing a novel strategy for developing efficient photocatalytic materials.