The photocatalytic performance of TiO2 coatings obtained by suspension plasma spray

Current human activities have led to water and air contamination having damaging effects on human health and potential irreparable impacts on the biosphere. Titanium dioxide (TiO₂), as one of the most recognized photocatalysts, allows the decomposition and the removal of waste organic compounds and harmful gases from water and the atmosphere. However, its limited efficiency has prompted extensive research to improve its performance and reduce cost. TiO₂ has three different polymorphs, anatase, rutile, and brookite. In literature, anatase is considered as one of the most important factors in the photoactivity efficiency of titania coatings. This study investigated a comparative study on the effect of the crystalline phase and more specifically anatase phase on the optical and photocatalytic performance of TiO₂ coatings produced by suspension plasma spray (SPS) on stainless steel substrates. The photocatalytic performance was evaluated by monitoring the degradation of methylene blue under visible light. The results noted the influential impact of anatase phase on the photocatalytic activity of TiO₂ coatings, while other significant parameters on photoactivity, like morphology and oxygen content, were constant. Additionally, coatings were characterized by X-ray diffractometry (XRD), thermogravimetry (TGA), UV–visible spectroscopy, and scanning electron microscopy (SEM).

Keywords: TiO₂, Photocatalytic activity, anatase, Suspension plasma spray