Enhanced photocatalytic degradation of organic pollutants using carbon nanotube mediated CuO and Bi₂WO₆ sandwich flaky structures

Abstract

CuO/CNT/Bi 2 WO 6 composites were synthesized with a solvothermal and impregnation-calcination method. This material combines the advantages of CuO, carbon nanotubes (CNTs) and Bi 2 WO 6 . The photocatalytic activity of the catalyst was evaluated by degrading phenolic organic pollutants such as p-nitrophenol and phenol under visible light. Compared with pure Bi 2 WO 6 , the photocatalytic activity of CuO/CNT/Bi 2 WO 6 composites is significantly increased by a factor of 3.52. The main reason for the increased activity is that the doped CNTs and CuO promote the separation of photogenerated hole and electron pairs. In addition, the coupling of π-π electrons on the CNT surface with the pollutants promotes the adsorption of the pollutants on the photocatalyst surface. The degradation rate of pure photocatalytic degradation of phenol can reach 60%. Under the synergistic effect of H 2 O 2 , the degradation rate of phenol can reach 94%, which is 1.56 times higher than that of pure photocatalysis. The UV-vis absorption spectrum shows that CuO/CNT/Bi 2 WO 6 has stronger light absorption ability in both visible and ultraviolet light regions. The trapping experiments of active species show that h + and • OH are the main active substances for photocatalytic degradation of phenol. This paper proposes a Z scheme mechanism to improve the photocatalytic performance.