Mesoporous WO 3 -graphene photocatalyst for photocatalytic degradation of Methylene Blue dye under visible light illumination

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