Synthesis and physico-chemical studies of vanadium doped zinc oxide nanoparticles and its photocatalysis

In this work we report the synthesis of vanadium doped zinc oxide nanoparticles by a sol-gel processing technique, and the vanadium concentrations in zinc oxide varied from 1 to 5 at.%. In our approach, the water for hydrolysis was slowly released by esterification reaction followed by a supercritical drying in ethyl alcohol. All synthesized samples were annealed in air at 500 A degrees C for 2 h. The obtained catalysts were characterized by fluorescence X, X-ray diffraction, transition electron microscopy and UV measurements. The structural properties showed that the obtained nanoparticles are single phase wurtzite structure and no secondary phases were detected which indicated that V ions substituted for Zn ions. The energy gap decreased gradually by increasing the doping concentration of V. The photocatalytic activities of powders were evaluated by the photocatalytic degradation of methylene blue (MB) under visible light irradiation. Compared with undoped ZnO and TiO2 P25 Degussa, it was found that the incorporation of vanadium in ZnO enhances the photocatalytic degradation, and ZnO:V-3% is most active photocatalyst for MB degradation than the other V-doped samples.