Surface modification by loading alkaline hydroxides to enhance the photoactivity of WO3

Surface modification on WO3 was carried out by loading KOH, NaOH and CsOH to study the influence of surface interactions on photocatalytic activity of this material. Photodegradation of 2-propanol, methanol, ethanol, acetone and propane in gas phase under visible light irradiation shows loading of KOH, NaOH and CsOH on WO3 enhanced the photodegradation rate about 4 and 3 times respectively. Loading of KOH on TiO2 were carried out for comparison and the results showed enhancement of photoactivity by KOH loading for WO3 which was much higher than that of TiO2. Increasing the rate of the photocatalytic reaction is attributed to compensation of the high tendency of WO3 for H+ donation and making multi-electron O-2 reduction by loading of KOH on the surface.