Preparation of BiPO4 nanosphere and its enhanced photocatalytic activity under simulated solar light degradation of tetracycline

As an effective and eco-friendly method, photocatalysis is a promising candidate for degrading tetracycline in aqueous solutions. In this work, a highly efficient BiPO4 nanosphere photocatalyst was successfully synthesized via a simple and facile hydrothermal method. The morphology, structure, optical properties, elemental composition, surface area and photoluminescence of the BiPO4 nanospheres were characterized by scanning electron microscopy, X-ray diffraction, UV-Vis, X-ray photoelectron spectroscopy and Brunauer-Emmett-Teller adsorption. Compared with the irregular BiPO4 particles, the BiPO4 nanospheres exhibited excellent photocatalytic activity for tetracycline (40 mg/L) degradation under simulated solar light irradiation. The rate constant was 0.00783 min(-1), which is up to 1.8 times as high as that of pure irregular BiPO4 particles. The improvement is ascribed to their unique morphology and smaller particle size. According to the electron spin resonance spectroscopy experiments, (OH)-O-center dot and O-center dot(2)- were testified to be the predominant active species. This work is expected to provide a possible design of BiPO4 nanosphere photocatalysts for the mitigation of environmental problems.