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

Combining hydrothermal treatment and photocatalytic deposition, W 6+ doping TiO 2 composites modified with Au nanoparticles (Au/W–TiO 2 ) 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 W 6+ doping TiO 2 clusters with mesoporous structures. The photocatalytic properties of the Au/W–TiO 2 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 TiO 2 , W 6+ doping TiO 2 and Au/TiO 2 , the resulting Au/W–TiO 2 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–TiO 2 , Au/TiO 2 , W–TiO 2 and bare TiO 2 , respectively. Furthermore, the degradation rate of organic dye is 98%, 90%, 76%, and 62% for Au/W–TiO 2 , Au/TiO 2 , W–TiO 2 and pure TiO 2 under visible light irradiation for 90   min, respectively. The enhanced photocatalytic activity is attributed to the synergetic effects of W 6+ 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 TiO 2 .