Photocatalytic performance and microstructure of thermal-sprayed nanostructured TiO2 coatings

Titanium dioxide coatings were deposited by atmospheric plasma spraying (APS) with the use of agglomerated P25 powders and different spraying parameters (e.g. power) to determine their influence on the microstructure and photocatalytic performance of the coatings. The microstructure of as-sprayed TiO2 coatings was characterized by scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD). The photocatalytic performance was evaluated by using methylene blue (MB) aqueous solution. The results showed that the power and flow of the secondary plasma gas have an important influence on the microstructure and on the anatase content of the TiO2 coatings. Porosity is also a key factor in determining the photocatalytic performance of the TiO2 coatings.