Effect of pH on the Microwave Hydrothermal Synthesis of BiVO4 Photocatalysts and Their Photocatalytic Activity Under Simulated Solar Light

The monoclinic scheelite structure of BiVO4 photocatalysts was prepared by the microwave hydrothermal method using an NH3 center dot H2O solution as the pH adjusting agent. The as-prepared powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and diffuse reflectance UV-vis spectroscopy (UV-vis-DRS). Experimental results indicate that the pH value of the reaction solution had a significant influence on the morphology of the BiVO4 that changed from a hierarchical sphere, bone-like to rod-like structure. The BiVO4 photocatalysts showed the enhanced photocatalytic activity for the degradation of methylene blue (MB) under simulated solar light irradiation. The best photocatalytic activity was attained for BiVO4 synthesized at pH 1.7.