Photocatalytic energy storage ability of TiO 2-WO 3 composite prepared by wet-chemical technique

TiO 2-WO 3 hybrid photocatalysts were prepared using wet-chemical technique, and their energy storage performance was characterized by electrochemical galvanostatic method. TiO 2 powder was coupled with WO 3 powder, which was used as electron pool and the reductive energy could be stored in. As a result, the prepared TiO 2-WO 3 had good energy storage ability while pure TiO 2 showed no capacity and pure WO 3 showed quite low performance. The energy storage ability was affected by the crystal structure of WO 3 and calcination temperature. The photocatalyst had better capacity when WO 3 had low degree of crystallinity, since its loose structure made it easier for electrons and cations to pass through. The photocatalytic energy storage performance was also affected by the molar ratio of TiO 2 to WO 3. Energy storage capacity was significantly dependent on the composition, reaching the maximum value at TiO 2/WO 3 1:1 (mol/mol).