ZrO2/TiO2 films prepared by plasma electrolytic oxidation and a post treatment

ZrO2/TiO2 films with high surface area and improved catalytic structures were prepared by the combination of plasma electrolytic oxidation technology with a sulfuric acid acidification and calcinations post treatments. The metal oxides composition, metal oxides phase and morphologies of the obtained films were determined by X-ray diffraction, energy dispersive spectroscopy and scanning electron microscopy. The post treatment conditions had significant influence on the phase composition and morphologies of the films. Both anatase and rutile phases of TiO2 in the film were observed by XRD. After the post processing, the surface of the film was covered by high crystalline TiO2 particles and the film surface is rough, leading to an increased surface area. With the increase of sulfuric acid concentration, the crystal form of the TiO2 particles transformed from cubic to spindle-like. Moreover, a tendency to form a multilevel structure was displayed with the increase of the calcinations temperature. The degradation of methylene blue under ultraviolet radiation indicated that the film with a post treatment showed a high photocatalytic activity. When catalyzed by the film prepared with a 750 °C calcination temperature, the degradation of the methylene blue reached 93.18%. Meanwhile, the regeneration experiments showed the prepared film catalyst had a good reusability.