Enhanced photocatalytic activity of Pt-TiO2/WO3 hybrid material with energy storage ability

We aimed at producing a photocatalyst having UV-vis activity with residual energy storage ability in absence of irradiation. We synthesized a series of catalysts with Pt supported over mixed titanium-tungsten oxides (TiO2/WO3). The methods were spray dried assisted sol-gel and crash precipitation. TiO2 maintained its tetragonal anatase phase and WO3 its monoclinic structure. The hybrid samples (PtxTW, where x = 01.2 wt.%) have significantly higher BET surface area (204.0 - 283.0 m(2)/g) compared to control Pt0.8T (265.0 m(2)/g) and Pt0.8W (54.5 m(2)/g) samples. XPS analysis detected the presence of metallic platinum (Pt degrees), which actively takes part in the enhanced photons absorption of the photocatalyst, as depicted from UV-vis-DRS study. The Pt0.8TW- optimum Pt loading- is characterized by a visible absorption edge at 501.0 nm compared to the control Pt0.8T (444.0 nm) and Pt0.8W (540.5 nm). Microscopy images showed homogenous and uniform distribution of the oxides, and Pt particles and the FTIR analyses evidenced greater adsorption of OH- groups on the hybrid samples surface. In the activity tests, the Pt0.8TW outperforms the other samples in the aqueous degradation of the model pollutant methylene blue (MB) (78.0% and 56.0% in UV and visible light), with an additional hour of energy storage ability in absence of irradiation, then reaching a final degradation of 98.0% and 77.0% under UV and Visible light, respectively. In connection to the activity tests, scavenging experiments revealed that hydrogen peroxide (H2O2) and hydroxyl radicals (OH center dot) were the main species responsible for the pollutant degradation.