Preparation of Two-Dimensional Layered CeO2/Bi2O3 Composites for Efficient Photocatalytic Desulfurization

Abstract

A two-dimensional layered CeO2/Bi2O3 composite was synthesized by microwave solvothermal method. X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscope (FESEM), transmission electron microscope (TEM), UV-Vis diffuse reflection spectroscopy (DRS), and X-ray photoelectron spectroscopy (XPS) were used to studied crystal structure, morphology, optical performance, elemental composition and the surface electronic state of the samples. The photocatalytic properties of the prepared samples were evaluated by photocatalytic desulfurization under visible light. When the molar ratio of Ce and Bi was 1:2, CeO2/Bi2O3 composite presented the highest photocatalytic desulfurization rate. Transient Photocurrent measurement, electrochemical impedance spectroscopy (EIS) and photoluminescence spectroscopy (PL) showed that CeO2 and Bi2O3 formed a heterojunction, which could promote the separation of photogenerated electrons and holes, improving the photocatalytic activity. Furthermore, it was found that the active species of hydroxyl radical (·OH) played an important role in the photocatalytic degradation of dibenzothiophene (DBT) based on the active species capture experiment. Finally, a plausible mechanism for the photocatalytic oxidative desulfurization of this nanocomposite was proposed.