Fabrication of TiO2-SrCO3 Composite Coatings by Suspension Plasma Spraying: Microstructure and Enhanced Visible Light Photocatalytic Performances

Abstract A novel TiO 2 -SrCO 3 co-catalyst with a porous structure was fabricated by suspension plasma spraying. SrTiO 3 as revealed by high-resolution TEM was formed by the chemical reaction of TiO 2 with SrCO 3 during the high-temperature plasma spraying. A narrow band gap (2.58 eV) and reduction in the recombination speed of photoinduced carriers of the coatings were detected by UV–visible diffuse reflectance spectrometry and fluorescence spectrometry, respectively. The enhanced visible light-driven photodegradation properties of the coatings resulted in promoted degradation of methylene blue. The composite coatings also demonstrated significantly pronounced bactericidal activities against the Gram-negative bacterium Escherichia coli than the pure TiO 2 coatings, achieving a killing rate of over 99.7%. The results give insights on the potential to fabricate large-scale nano-TiO 2 -based porous photocatalytic coatings by suspension plasma spraying for versatile environmental applications. Graphic Abstract