Controllable fabrication of heterostructured Au/Bi₂O₃ with plasmon effect for efficient photodegradation of rhodamine 6G

Three-dimensional (BiO)₂CO₃ (BSC) nanostructures were synthesised by a hydrothermal reaction, and Bi₂O₃ nanoparticles were then obtained by calcining BSC precursor at different temperatures. BSC and Bi₂O₃ samples were then sputtering coated with Au to get the resultant Au/BSC and Au/Bi₂O₃ for the investigation of the effect of the Au coating on the photocatalytic performance of the samples. The phase structure, morphology and composition of the samples were characterised by X-ray diffraction, scanning electron microscopy and energy-dispersive spectroscopy (EDS). UV–vis diffuse reflectance spectra were used to measure the response of different catalysts to UV–vis light. The photocatalytic activity was investigated for the degradation of rhodamine 6G at room temperature and the light intensity was 1 sun. Bi₂O₃ exhibited better photocatalytic performance than BSC due to the narrow band gap of Bi₂O₃, and the coating of Au also endowed the samples with higher photocatalytic capability as compared to the bare one.