Influence of FeTiO3 Formation on Photocatalytic Property of Plasma Sprayed TiO2 Coatings

摘要

To inhibit the rapid recombination of excited electrons and holes in photocatalysis, the p-n junction was formed by plasma spraying TiO2-Fe3O4 composite powders. The microstructure, morphology and composition of the sprayed coating and splat were analyzed using electron probe surface roughness analyzer (ERA-8800FE), energy dispersive analysis of X-ray (EDAX) and X-ray diffraction. The results showed that the n-type TiO2 semiconductor particle reacted with Fe3O4 particle and concurrently produced p-type FeTiO3, and consequently formed p-n junction in the interface between the TiO2 lamella and FeTiO3 compound. This phenomenon was clearly proved by photocurrent-potential measurement and line analysis results. For the formation of micro p-n junction, the photocatalytic activity of TiO2-Fe3O4 coating was approximately two times higher than that of T1O2 coating. From these investigations, a promising approach for manufacturing high performance photocatalytic coating by plasma spraying was suggested.