Solvothermal synthesis and characterization of hierarchical spindle-like BiPO4 aggregates

Abstract

Monodispersed spindle-like BiPO4 aggregates with uniform morphology and size were prepared by a solvothermal route with ethylene glycol (EG)/water as mixed solvent, bismuth nitrate and sodium tripolyphosphate (STPP) as raw materials. The products were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and UV-vis absorption spectroscopy. The results indicate that obtained BiPO4 products are hexagonal phase and have good crystallinity and high purity. Additionally, it is found that the both STPP and mixed solvent play a crucial role in the formation of the spindle-like BiPO4 aggregates, which are constructed through oriented aggregation of nanoparticles. The possible formation process was initially presented. Moreover, the bandgap energy of these novel spindle-like BiPO4 aggregates is also estimated as 3.46eV from the UV-vis absorption spectrum.