Role of Calcination Temperature on the Photocata-lytic Activity of Zinc Tungstate Nanoparticles Syn-thesized by a Novel Route

The studies on photocatalysts such as TiO2, ZnO, ZnWO4 have suggested that the crystallinity, surface area, phase purity, electron – hole recombination rate etc. play key roles in their catalytic activity. In the present work, the effect of calcination temperature on the photocatalytic activity of ZnWO4 nanoparticles synthesized by calcining ZnO and WO3 nanoparticle mixture is explored. The structural characterization of the samples were carried out using X-Ray Diffraction (XRD) and Raman techniques. Photocatalytic activity of the samples were studied on the photodegradation of Methylene Blue. The pseudo-first-order rate constant, kapp(min-1 ),was calculated from the slope of ln (Co/Ct) versus irradiation time t. From the study of photodegradation of MB in the presence of ZnWO4 nanoparticles, it was observed that the samples calcined at 8000C displayed more photocatalytic activity compared to other samples.