Construction of Bi2O3/Bi28O32(SO4)10 three-dimensional microsphere heterojunction and the photoelectrocatalysis performance

Abstract Through electrodeposition and annealing, a Bi2O3/Bi28O32(SO4)10/FTO photoelectrode with three-dimensional spherical morphology was prepared. X-ray diffraction characterization (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), Transmission electron microscope (TEM), ultraviolet diffuse reflection spectrum (DRS), electrochemicalimpedance (EIS), photoluminescence (PL), transient state photocurrent, Mott-Schottky and other methods were carried out to characterize the elemental composition, crystal morphology and optical properties, as well as the photocatalytic performance, respectively. The results showed that the film contains Bi, O and S elements. Bi2O3/Bi28O32(SO4)10/FTO electrode was 10.5 times the photocurrent density of the Bi28O32(SO4)10/FTO electrode and 2.15 times the photocatalytic degradation efficiency. Capture experiments showed that hydroxyl radicals ( OH) and holes (h+) are the main reactants in the degradation process. The Bi2O3/Bi28O32(SO4)10/FTO composite electrode has good stability. After four degradation cycles, the removal rate of methylene blue was basically unchanged. The increase in photocatalytic activity is attributed to the increase in the visible light absorption range and the formation of heterojunction structures. Finally, the charge transfer mechanism of Bi2O3/Bi28O32(SO4)10/FTO was proposed.