Facile fix of porous composite titania photocatalytic film by PEO

Porous composite titania photocatalytic films were fixed on steel substrate by plasma electrolytic oxidation. Aluminate solution containing TiO₂ nanopowders was used as electrolyte. The microstructure and photocatalytic activities of the films were studied. The investigation results revealed that when the electrolyte contained a few TiO₂ powders, the film consisted of A-TiO₂, Al₂TiO₅ and a few γ-Al₂O₃. With increasing the concentration of TiO₂ powders in the electrolyte, γ-Al₂O₃ phase disappeared, and the surface content of Ti element increased. The film surface was coarse and porous, which became more and more coarse with more titania powders in the electrolyte. With increasing the concentration of titania powders in the electrolyte, the photocatalytic activity of the film gradually increased. Within 2 h irradiation, the biggest photodegradation ratio of rhodamine B increased to 88% for the film obtained with 8 g L⁻¹ titania powders in the electrolyte.