A novel two-steps solvothermal synthesis of nanosized BiPO₄ with enhanced photocatalytic activity

Nano-sized BiPO₄ has been successfully synthesized via a novel designed two-steps solvothermal route using ethylene glycol as solvent. Comparing with traditional hydrothermal method, the novel approach could readily prepare BiPO₄ with shorter time. The photocatalytic activity of prepared BiPO₄ has been tested via degradation of methylene blue (MB) under light irradiation. The experimental results show that the BiPO₄ prepared by novel route had enhanced photocatalytic activity and the synthetic parameters also impact the reaction rate meaningfully. Finally, the obtained samples have been widely characterized by means of powder X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area, scanning electron microscopy (SEM), UV-vis diffuse reflectance spectra (DRS) and Fourier transformed infrared (FTIR) spectra. BiPO₄ prepared by this novel approach have a particles size below 100 nm, which is a big improvement by comparing with previous works (few micrometer). The effect of EG during the formation of BiPO₄ has been discussed and a possible formation mechanism is proposed.