Effect of Hydrothermal Reaction Temperature on the Photocatalytic Properties of CdWO4-RGO Nanocomposites

Cadmium tungstate (CdWO4) nanorods and CdWO4-reduced graphene oxide (RGO) nanocomposites have been prepared by the hydrothermal method at 140, 160 and 180oC reaction temperatures. The synthesized samples were characterized by X-ray powder diffraction, scanning electron microscopy (SEM), Fourier transform infrared, photoluminescence spectroscopy and Raman spectroscopy. SEM image showed the pure sample consist of nanorods with 50-100 nm diameter and ~1 µm length. The images of the nanocomposite samples clearly showed existence of CdWO4 nanorods and graphene sheets together. The photocatalytic activities of the as-prepared samples were investigated by degradation of methylene blue under the visible light irradiation. An enhancement in photocatalytic activity was observed with CdWO4-RGO nanocomposites in compare with the pure CdWO4. The effect of reaction temperature on the photocatalytic activity of the prepared nanocomposites was also investigated. The results showed that the CdWO4-RGO sample which prepared at 160oC has more catalytic activity than the other samples.