Phase Structure Regulation and Photocatalytic Degradation Properties of α/β-Bi₂O₃ Films Prepared by Plasma Spraying-Chemical Vapor Deposition

To obtain easily recycled photocatalyst and improve the reusing practicability for waste water treatment, Bi₂O₃ films were prepared by a plasma spray-chemical vapor deposition method, and the effects of deposition temperature and heat-treatment temperature on the morphology and phase composition of Bi₂O₃ films were investigated. The morphology and composition of the films were characterized by field-emission scanning electron microscopy, X-ray diffraction and high-resolution transmission electron microscopy. The band gaps of α/β-Bi₂O₃ at different heat treatment temperatures were determined by ultraviolet-visable diffuse reflectance spectrometry. The results show that the deposition temperature and heat-treatment temperature affect the microstructure of Bi₂O₃ films and the proportion of α and β phases, while the influence of deposition temperature is more dominant rather than that of heat-treatment temperature. The proportion of β phase gradually converts to α phase and the band gap of α-Bi₂O₃ and β-Bi₂O₃ increases when the heat-treatment temperature increases. The Bi₂O₃ films exhibit a good photocatalytic degradation performance for Methyl Orange and Bisphenol A.