Favorable recycling photocatalyst TiO₂/CFA: Effects of calcination temperature on the structural property and photocatalytic activity

A batch of TiO₂/CFA photocatalysts was prepared by using coal fly ash (CFA), waste discharged from coal-fired power plant, as substrate. The effects of calcination temperature on the structural property of TiO ₂/CFA, such as morphology, crystal structure, porous property and light absorption characteristic were investigated in detail. Further more, the effects of calcination temperature on the photocatalytic activity and the recycling property of TiO₂/CFA were studied by the photocatalytic decoloration and mineralization of methyl orange solution. The results show that calcination temperature affected the photocatalytic activity and the recycling property of TiO₂/CFA by many ways: the increase in calcination temperature can improve the crystallization of TiO₂, decrease the specific surface area of TiO₂/CFA, promote the grain growth of TiO₂, and can enhance the mechanical stability of TiO₂/CFA in the range of 400-700 °C. 700 °C is the optimum calcination temperature for obtaining the optimal photocatalytic activity and re-use property of TiO₂/CFA under the conditions investigated in this study.