Development of Photocatalytic Active TiO2 Surfaces by Thermal Spraying of Nanopowders
Filofteia-Laura Toma, Ghislaine Bertrand, Didier Klein
Journal of Nanomaterials
Abstract
Titanium dioxide is a very useful photocatalyst for the decomposition and diminution of environmental water and air pollutants. In such applications, it can be used as slurry or as immobilized coating obtained by dierent deposition methods. The studies performed in the last years showed that thermal spraying could be employed to elaborate TiO2 coatings with high performance for the decomposition of organic compounds. This manuscript presents a comparative study on the microstructure and photocatalytic performance of titania coatings obtained by dierent thermal spray techniques: atmospheric plasma spraying (APS), suspension plasma spraying (SPS), and high-velocity oxygen fuel spray process (HVOF). Dierent titania powders and suspensions were used to study the inuence of the feedstock materials on the coating characteristics. The deposits were mainly characterised by SEM and X-ray diraction. The photocatalytic performance was evaluated from the removal of nitrogen oxides. The experimental results showed that a drastic reduction of the pollutant concentration was obtained in presence of coatings elaborated by suspension plasma spraying. TiO2 coatings resulting from the spraying of agglomerated powder presentd less eciency. That was mainly explained by the signicant phase transformation from anatase to rutile that occurred in the enthalpic source during the spray processes.
Keywords:Nanopowders; titania; pollutants; Titanium dioxide; comparative study; TiO coatings; atmospheric plasma; Thermal Spraying; suspension plasma
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