Comparison of the Photocatalytic Behavior of TiO TiO2 CoatingsElaborated by Different Thermal Spraying Processes

摘要

In this paper a comparative study on the microstructure andphotocatalytic performances of titanium dioxide coatingselaborated by various thermal spraying methods (plasmaspraying in atmospheric conditions, suspension plasmaspraying and high-velocity oxy-fuel spraying) was proposed.Agglomerated spray-dried anatase TiOTiO2 powder was used asfeedstock material for spraying. Morphology andmicrostructural characteristics of the coatings were mainlystudied by scanning electron microscopy and X-raydiffraction. The photocatalytic behavior of the TiOTiO2-basedsurfaces was evaluated from the conversion rate of gaseousnitrogen oxides (Nox). It was found that the crystallinestructure strongly depended on the technique of thermalspraying deposition. Moreover, a high amount of anatase wassuitable for the photocatalytic degradation of the pollutants.Suspension plasma spraying permitted to retain the originalanatase phase and to obtain very reactive TiO-TiO2 surfaces for thenitrogen oxides removal.