Preparation of rod-like BiPO4 by microwave hydrothermal method and study on its photocatalytic properties

In this study, BiPO₄ was prepared by microwave hydrothermal and precipitation method, respectively. The photocatalytic activities of the two type of BiPO₄ were evaluated by degradation of acid orange Ⅱ and methylene blue with 400 W metal halide lamps simulating as sunlight. The study mainly focuses on the BiPO₄ prepared by microwave hydrothermal method. The photocatalysts were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), UV-Vis diffuse reflectance spectra (UV-vis DRS) and Fourier transform infrared spectroscopy (FT-IR). The UV-vis DRS analysis indicated that the band gap of BiPO₄ prepared by microwave hydrothermal method was 4.05 eV, narrower than that of the sample prepared by precipitation method. The results of photocatalytic degradation demonstrated that the degradation rate constants of the BiPO₄ prepared by microwave hydrothermal method were 6.8 and 0.5 times higher than that of those prepared by precipitation method.