Effects of oxidation temperature on the microstructure and photocatalytic activity of the TiO2 coating

Abstract

Titanium coatings have been prepared on the surface of 1mm ZrO₂ balls by mechanical ball mill, then the coatings are oxidized to photocatalyst TiO₂ films at 400~600°C. XRD, SEM, EDS and OM were used to analyze the microstructure of the films. The photocatalytic activity of the samples is also evaluated. After that the effects of oxidation temperature on the microstructure and photocatalytic activity of the films has been discussed. Result shows that, oxygen elements are imported into the inner coatings by the gaps existed in the Ti coatings, which makes the Ti particles oxidized from surface to core, finally the films with TiO₂+Ti composite microstructure are obtained. The films have the best photocatalytic performance with degradation rate of methyl orange solution 79.08% by oxidation at 500°C, this owing to the existence of anatase and the composite microstructure.