Photocatalytic degradation of malachite green based on PW12/MWCNTs/Bi₂O₃ composite photocatalyst

In this study, Bi₂O₃ nanoparticles are prepared via an impregnation method and modified using multi-walled carbon nanotubes (MWCNTs) and PW₁₂. XRD reveals that the prepared Bi₂O₃ corresponded to the monoclinic α-phase. SEM results reveal that the composite consists of a series of nanosheets with flower-like structures. In this study, malachite green (MG) is used as a simulated contaminant to test the degradation capability of the compound under sunlight, and the effect of PW₁₂ doping on the photocatalytic properties of the sample is investigated. The results show that the degradation kinetic constant of 0.3 PW₁₂/MWCNTs/Bi₂O₃ (0.8125 h⁻¹) is about 3 times that of Bi₂O₃ (0.2767 h⁻¹). The ternary complex containing 30% PW₁₂ has a degradation rate of 95% in 2.5 h. h⁺ and \(^\cdot {\text{O}}_2^-\) ${}^{·}{\text{O}}_2^{-}$ were the major active species in the photocatalytic degradation of MG.