The influence of preparation method on the photocatalytic performance of g-C3N4/WO3 composite photocatalyst

g-C3N4/WO3 composites were prepared by three different methods: ultrasonic dispersion, calcination, and hydrothermal method. X-ray diffraction (XRD), UV-vis spectroscopy, nitrogen adsorption, photoluminescence (PL), X-ray photoelectron spectroscopy (XPS), and Electrochemical impedance spectroscopy (EIS) were used to characterize the prepared catalysts. The results indicated that the preparation method significantly influenced the interaction between g-C3N4 and WO3, leading to the obvious difference in separation rate of photogenerated electrons and holes. The activities were tested in photocatalytic Rhodamine B (RhB) degradation and H2 production under visible light. The activities of g-C3N4/WO3 composites were obviously higher than that of single g-C3N4 or WO3. The composite prepared by the hydrothermal method exhibited the highest photocatalytic activity.