Studies of the photocatalytic efficiency of titanium dioxide powders and coatingsobtained by plasma spraying

摘要

Titanium dioxide (TiO2) is one of the most important photocatalyst that allows the environmental purification ofwater and air by the decomposition of toxic organic compounds and removal of harmful gases. In the photocatalyticapplications, TiO2 can be used in form of powder or coating. In this paper, two techniques of deposition were usedto elaborate thin deposits starting from an agglomerated TiO2 anatase nanopowder: conventional plasma sprayingin atmospheric conditions and suspension plasma spraying. The photocatalytic efficiency of the coatings wasperformed with respect to nitrogen oxides (NOx) and compared with the photocatalytic activity of the TiO2 DegussaP25 powder. Differences in the photocatalytic efficiencies of the nanocoatings obtained by the two techniques ofplasma spraying were obtained. The coatings elaborated by suspension plasma spraying have poor mechanicalproperties but better photocatalytic efficiencies. This method is a promising technique to elaborate photocatalyticcoatings for the removal of different air pollutants.