Mesoporous WO-graphene photocatalyst for photocatalytic degradation of Methylene Blue dye under visible light illumination.

Advanced oxidation technologies are a friendly environmental approach for the remediation of industrial wastewaters. Here, one pot synthesis of mesoporous WO and WO-graphene oxide (GO) nanocomposites has been performed through the sol-gel method. Then, platinum (Pt) nanoparticles were deposited onto the WO and WO-GO nanocomposite through photochemical reduction to produce mesoporous Pt/WO and Pt/WO-GO nanocomposites. X-ray diffraction (XRD) findings exhibit a formation of monoclinic and triclinic WO phases. Transmission Electron Microscope (TEM) images of Pt/WO-GO nanocomposites exhibited that WO nanoparticles are obviously agglomerated and the particle sizes of Pt and WO are ~10nm and 20-50nm, respectively. The mesoporous Pt/WO and Pt/WO-GO nanocomposites were assessed for photocatalytic degradation of Methylene Blue (MB) as a probe molecule under visible light illumination. The findings showed that mesoporous Pt/WO, WO-GO and Pt/WO-GO nanocomposites exhibited much higher photocatalytic efficiencies than the pure WO. The photodegradation rates by mesoporous Pt/WO-GO nanocomposites are 3, 2 and 1.15 times greater than those by mesoporous WO, WO-GO, and Pt/WO, respectively. The key factors of the enhanced photocatalytic performance of Pt/WO-GO nanocomposites could be explained by the highly freedom electron transfer through the synergetic effect between WO and GO sheets, in addition to the Pt nanoparticles that act as active sites for O reduction, which suppresses the electron hole pair recombination in the Pt/WO-GO nanocomposites.