Effect of Heat Treatment Temperature on Energy Storage Ability of TiO2-WO3 Composite Photocatalyst

TiO2-WO3 photocatalyst powder was made from TiO2 powder and soluble tungstic acid. The energy storage behavior was characterized by electrochemical galvanostatic method. Combined with XRD, TEM and BET, crystalline form and crystallinity changing of WO3 with heat treatment was studied. TiO2-WO3 composite materials have energy storage ability in electrochemical measurement. The crystallinity of WO3 has strong influence on samples ˉ performance. When WO3 is tungstite or amorphous, the TiO2-WO3 composites have no or quite low energy storage capacity. The energy storage capacity is improved with the crystallinty of WO3 increasing. The maximum of TiO2-WO3 energy storage capacity is 0.83 0-3 C ¤mg-1. But when the crystallinity of WO3 is high, the energy storage capacity decreases. And degradation experiment displays that Rhodamine B can be degraded in darkness by the TiO2-WO3 photocatalyst with energy storage ability, and the degradation efficiency reaches 11%.