3D hierarchical Zn3(OH)2V2O7·2H2O and Zn3(VO4)2 microspheres: Synthesis, characterization and photoluminescence

Via a simple glycine-assisted hydrothermal route, large-scale 3D hierarchical Zn3(OH)2V2O7·2H2O microspheres have been fabricated. Their purity, crystalline phase, morphologies and thermal stability were characterized by X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), Fourier transform IR (FTIR), scanning electron microscopy (SEM) and thermogravimetry-differential scanning calorimetry (TG-DSC). The SEM results indicate that the microspheres are self-assembled by numerous nanoflakes with mean thickness of 100 nm. Some factors influencing the morphologies of the Zn3(OH)2V2O7·2H2O micro-/nanostructures have been systematically investigated, as well as quantity of glycine and the reaction time. The possible mechanism of the crystal growth and assembled procedure were also proposed. The as-prepared Zn3(OH)2V2O7·2H2O can be transformed into Zn3(VO4)2 with the similar morphologies by calcination in air at 600 °C. Furthermore, the photoluminescent properties of both Zn3(OH)2V2O7·2H2O and Zn3(VO4)2 were studied and exhibited different spectra.