The Effects of Oxidation Temperature on the Microstructure and Photocatalytic Activity of the TiO2 Coating

Abstract

Titanium coatings were prepared on the surface of 1mm ZrO₂ balls by mechanical ball mill, then the coatings were oxidized to photocatalytic TiO₂ films at 400 ~ 600 °C. X-Ray Diffraction, Scanning Electron Microscope, Energy Dispersive Spectroscopy and Optical Microscope were used to analyze the microstructure and crystal form of the films. The photocatalytic activity of the samples was also evaluated. After that, the effects of oxidation temperature on the microstructure and photocatalytic activity of the films were discussed. The results show that the fabricated coatings are uneven, with average thickness of 60 μm. In the process of oxidation, oxygen is imported into the inner coatings by the gaps existed in the Ti coatings, which makes the Ti particles oxidize from surface to core, finally the films with TiO₂ + Ti composite microstructure are obtained. The films oxidized at 500 °C have the best photocatalytic performance with the degradation rate of methyl orange solution 79.08 %, this owing to the existence of anatase and the TiO₂+Ti composite microstructure. The result will provide theoretical basis for the fabrication of efficient photocatalytic film.

DOI: http://dx.doi.org/10.5755/j01.ms.23.2.15590