Photocatalytic Degradation of Acid Orange 7 on TiO2 Films Prepared from Various Powder Catalysts

The advantage of using particulate layers in water and air cleaning is in the combination of two important features in photocatalysis: high surface area of powder particles and immobilization of photocatalyst. The present paper deals with the preparation of particulate TiO2 layers using three different techniques: sedimentation, electrophoresis and dip-coating and different particulate photocatalyst namely P25 (Degussa) and anatase Ti1 and Ti2 of Czech production. Photocatalytic activity was tested using an aqueous solution of a model azo-dye Acid Orange 7. It was found that the method of preparation has not a significant impact on the photocatalytic properties of resulting layer. Surprisingly the immobilized powder with the lowest surface area and crystal size around 170 nm exhibit the best photocatalytic performance.