One-step synthesis of SbPO4 hollow spheres by a self-sacrificed template method

Abstract

High purity SbPO₄ hollow spheres assembled by nanoparticles were successfully fabricated by a template-free solvothermal reaction in a mixed solvent of water, ethanol, and oleic acid. The synthetic conditions for the hollow sphere SbPO₄ were monitored by a series of time-resolved experiments and further optimized by adjusting the solvent ratio and pH value in the reaction system. Based on XRD and SEM characterization, it is interesting to reveal a phase conversion process from Sb₄O₅Cl₂ to SbPO₄ as well as morphology evolution. The phase and morphology transition mechanism was discussed from the chemical equilibrium perspective. Size distributions of Sb₄O₅Cl₂ and SbPO₄ samples were in a narrow range of 7 to 13 μm. The Sb₄O₅Cl₂ spheres were constructed in situ by nanosheets, which act as self-sacrificed templates for the SbPO₄ hollow spheres. Room-temperature alternative current impedance measurements indicate that the permittivity for the SbPO₄ hollow spheres is as high as 130 at 40 Hz, which obviously originates from the interfacial effects with numerous carriers blocked. The synthetic methodology reported in this work can be applied to a broad class of assembled nanostructures for optimization of dielectric performance.