The enhanced photocatalytic activity and self-cleaning properties of mesoporous SiO2 coated Cu-Bi2O3 thin films

Abstract

Mesoporous SiO₂ coated Cu-Bi₂O₃ thin films (meso-SiO₂/Cu-Bi₂O₃) were prepared on glass substrates using a simple sol–gel/spin-coating method. The structure and optical properties were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, a UV-vis spectrophotometer and a water contact angle meter. The photocatalytic activity and self-cleaning properties of the films were investigated through the degradation of methyl orange and stearic acid, respectively. It was found that the meso-SiO₂/Cu-Bi₂O₃ thin films were highly transparent and showed excellent superhydrophilicity even in the dark. The thin films exhibited enhanced photocatalytic activity and self-cleaning properties compared to pure Bi₂O₃ films, which was attributed to the cooperation of the interfacial charge transfer between Bi₂O₃ and surface Cu species as well as the unique mesoporous SiO₂ structure. The results showed that the films can be used as promising self-cleaning and antifogging materials.