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

In order to more easily separate TiO₂ photocatalyst from the treated wastewater, TiO₂ was immobilized on the surface of coal fly ash by employing three kinds of approaches, sol-gel procedure, ambient hydrolysis procedure and hybrid slurry procedure. The effects of loading method on the structural property of TiO₂-coated coal fly ash (TiO ₂/CFA), such as morphology, crystal structure, porous propertyand ultraviolet-visible absorption were investigated, and the photocatalytic activity of TiO₂/CFA was evaluated by the photocatalytic depigmentation and mineralization of methyl orange solution. The results show that TiO₂/CFA particles are easy to precipitate and recover fromwater. The hybrid slurry procedure is a more proper method to immobilize TiO₂ on coal fly ash than the other two procedures because the TiO₂/CFA sample prepared by hybrid slurry procedure exhibits higher photocatalytic activity and better repeatability.