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5241 |
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Investigating influences of suspension plasma spray parameters on photocatalytic activity of TiO2 films
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Phuong Vu* / University of Stuttgart, Germany Nikolai Otto / Institut für Siedlungswasserbau, Wassergüte- und Abfallwirtschaft, Universität Stuttgart., Germany Andreas Vogel/ Institut für Fertigungstechnologie keramischer Bauteile, Universität Stuttgart, Germany Frank Kern/ Institut für Fertigungstechnologie keramischer Bauteile, Universität Stuttgart, Germany Andreas Killinger/ Institut für Fertigungstechnologie keramischer Bauteile, Universität Stuttgart, Germany Rainer Gadow/ Institut für Fertigungstechnologie keramischer Bauteile, Universität Stuttgart, Germany |
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In recent studies, the suspension plasma spray technology (SPS) was shown as a promising method for deposition of photocatalytic TiO2 coatings on glass substrates. However, only little information about the effects of SPS process parameters on the resulting photocatalytic activity is available. In this study, several suspensions were prepared from different powders and various dispersion mediums successively sprayed. Four titania powders with a proven photocatalytic track record, Evonik P25, Kronoclean 7050, Hombicat UV100 and Sigma Aldrich were used to study the influence of starting powder type. Furthermore, compositions of the dispersing medium were varied in order to investigate their influence on coating structure, adhesion to substrate and photocatalytic activity. Degradation of methylene blue was tested as a marker for the photocatalytic activity. At chosen torch parameters, alcohol and water in a ratio of 1:3 was identified as the best composition. Suspensions sprayed with higher alcohol content suffered from the reduction in anatase phase; higher water content reduced the coating adhesion to the substrate. Regarding the initial powders, films made of Evonik P25 and Sigma Aldrich TiO2 had higher photocatalytic activity than others. Moreover, the photocatalytic activity of doped TiO2 coatings illuminated by both an artificial light and sunlight were investigated. Keywords: titania, suspension plasma spray, photocatalysis, water treatment. |