Comparison of SFS, SPS and HVSFS for the Production of Photocatalytic Titania Coatings

Abstract

This study assesses the viability of three suspension spray processes for producing photocatalytic TiO2. In the experiments, flame, plasma, and HVOF torches were used to spray TiO2 suspensions onto stainless steel substrates, varying process parameters in order to gauge their effect on phase composition, crystal size and, in turn, photoactivity. The TiO2 samples were characterized by means of XRD, SEM, and UV-Vis analysis and photocatalytic hydrogen-production testing. Suspension flame spraying proved to be the most effective method, producing phase-controlled nanostructured titania 32% more photoactive than the SPS samples and up to five times more active than analogous coatings produced by CVD.