Facile Synthesis of Ternary Dual Z−Scheme G−C3n4/Bi2moo6/Ceo2 Photocatalyst with Enhanced 4–Chlorophenol Removal: Degradation Pathways and Mechanism

Abstract

The present work focused on the construction of a novel ternary g–C 3 N 4 /Bi 2 MoO 6 /CeO 2 nanocomposite and the application for photocatalytic removal of 4–CP under irradiation. The g–C 3 N 4 /Bi 2 MoO 6 /CeO 2 photocatalysts were successfully synthesized by a facile solid–state thermolysis assisted ultrasonic dispersion to introduce g–C 3 N 4 nanosheets into Bi 2 MoO 6 /CeO 2 composite. Morphology characterization revealed that the Bi 2 MoO 6 /CeO 2 spherical structure uniformly dispersed on the g–C 3 N 4 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 Bi 2 MoO 6 /CeO 2 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 • O 2 − 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.

Keywords: Photocatalysts, Dual Z-scheme, g-C3N4, 4-chlorophenol, Intermediates