Facile synthesis of ternary dual Z−scheme g−C3N4/Bi2MoO6/CeO2 photocatalyst with enhanced 4–chlorophenol removal: Degradation pathways and mechanism

The design of visible-light-driven photocatalysts has been rapidly developed due to the great application potential in environmental pollution remediation. The present work focused on the construction of a novel ternary g-C3N4/Bi2MoO6/CeO2 nanocomposite and the application for photocatalytic removal of 4-CP under irradiation. The g-C3N4/Bi2MoO6/CeO2 photocatalysts were successfully synthesized by a facile solid-state thermolysis assisted ultrasonic dispersion to introduce g-C3N4 nanosheets into Bi2MoO6/CeO2 composite. Morphology characterization revealed that the Bi2MoO6/CeO2 spherical structure uniformly dispersed on the g-C3N4 nanosheets and the close interface contact induced the generation of dual Z-scheme heterojunction. The as-prepared photocatalysts shown enhanced catalytic activity in comparison with binary Bi2MoO6/CeO2 composites and the optimal CBC-20% exhibited the highest degradation efficiency of 99.1% for 4-CP under 80 min illumination, which was attributed to the efficient separation of photogenerated e--h+ pairs under the dual Z-scheme charges transfer mode. Additionally, combined with trapping experiments and EPR analysis, 4-CP was decomposed mainly by the active species •O2- and h+ with a marginal assistance of •OH during the photocatalytic process. The intermediates for 4-CP degradation were analyzed and a reasonable degradation pathway was proposed.