Abstract: Polyvinylpyrrolidone(PVP)/vanadyl glycolate (VO(OCH2-CH2O)) core-shell microspheres were assembled by soft-templating method using vanadyl acetylacetone (VO(acac₂) as raw materials. And then vanadium pentoxide (V₂O₅) hollow spheres with particle size from 0.5 to 1μm were obtained by the calcination of composite microspheres. SEM, TEM and XRD were adopted to characterize the spherical morphology, hollow structure and phase composition of the final product, respectively. The mechanism of the formation of V₂O₅ hollow spheres was discussed based on the FTIR of VO(acac)₂, PVP dissolved in EG, VO(acac)2 dissolved in EG, VO(OCH₂-CH₂O)/PVP microspheres and the DTA curve of composite microspheres. Effects of concentration of reagents, the time of reaction on the experiment were studied. The results indicate that the core-shell composite microspheres can be prepared through the precise control of the concentration of PVP and VO(acac)₂, and the microspheres will be formed with ideal shape and surface morphology with reaction time ranging from 75min to 90min.

Key words: templating self-assembly, PVP/vanadium precursor composite microspheres, V₂O₅, hollow microspheres