Synthesis of composite WO3/TiO2 nanoparticles by flame-assisted spray pyrolysis and their photocatalytic activity

Combining of tungsten trioxide (WO3) with titanium dioxide (TiO2) have been an interesting research subject because different from conventional TiO2 material, this composite can be used and activated under visible-light irradiation and has better photocatalytic efficiency. The purpose of this study was to synthesize composite WO3/TiO2 nanoparticles and to investigate the detail effect of composition of ammonium metatungstate (AMT, as a WO3 source) and titanium isopropoxide (TTIP, as a TiO2 source) in the wide range composition ratio on particle morphology (i.e., outer size (from 20 to 90 nm), shape, and structure), crystallinity, and photocatalytic performance. To synthesize composite WO3/TiO2 nanoparticles, a flame-assisted spray-pyrolysis method was used. Experimental results showed that the amount of AMT (from 0 to 25 wt%) had shown a significant impact on the photocatalytic performance, however deviation of this amount had improve catalyst performance slightly. The change of photocatalytic activity is mainly influenced by band gap energy and surface area. To confirm the fundamental reason for this catalytic improvement, the effect of WO3 and TiO2 amounts on surface area, light absorbance, and charge separation analysis was investigated. The experimental results were also completed along with the proposal photocatalytic mechanism of particles containing WO3 and TiO2. In addition, although our present photocatalytic activity still needs to be improved, the present results open new information for creating more varied properties for application explorations. (C) 2014 Elsevier B.V. All rights reserved.