Synergetic effects of W6+ doping and Au modification on the photocatalytic performance of mesoporous TiO2 clusters

Combining hydrothermal treatment and photocatalytic deposition, W6+ doping TiO2 composites modified with Au nanoparticles (Au/W-TiO2) were synthesized successfully. A series of characterization techniques including X-ray diffraction, scanning electron microscopy, transmission electron microscopy and N-2 adsorption indicated that the Au nanoparticles are distributed homogeneously on the W6+ doping TiO2 clusters with mesoporous structures. The photocatalytic properties of the Au/W-TiO2 nanocomposites were evaluated through the photodegradation of organic dye in aqueous solution and characterized in detail by UV-visible diffuse reflectance spectra and PL fluorescence spectra. Compared with the three samples of pristine TiO2, W6+ doping TiO2 and Au/TiO2, the resulting Au/W-TiO2 nanocomposites exhibited an enhanced photocatalytic performance for degradation of contaminant under simulated solar light and visible light irradiation. Under simulated solar light irradiation (duration: 15 min), 84.6%, 77.8%, 67.8% and 47.6% of organic dye was decomposed by Au/W-TiO2, Au/TiO2, W-TiO2 and bare TiO2, respectively. Furthermore, the degradation rate of organic dye is 98%, 90%, 76%, and 62% for Au/W-TiO2, Au/TiO2, W-TiO2 and pure TiO2 under visible light irradiation for 90 min, respectively. The enhanced photocatalytic activity is attributed to the synergetic effects of W6+ doping and Au modification, which can effectively improve the light absorption intensity and, the range, increase the adsorption active sites and reduce the electron-hole pair recombination in TiO2. (C) 2015 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.