In this paper a comparative study on the microstructure and photocatalytic performance of titanium dioxide coatings elaborated by various thermal spray methods - atmospheric and vacuum plasma spraying, HVOF and suspension plasma spraying - was proposed. Agglomerated spray-dried anatase TiO₂ and TiO₂-Al powders were used as feedstock materials for spraying. Morphology and micro-structural characteristics of the coatings were mainly studied by scanning electron microscopy, X-ray diffraction and thermal analysis. The photocatalytic behaviour of the TiO₂-based surfaces was evaluated from the conversion ratio of nitrogen oxides. It was found that the ratio of the anatase phase strongly depends on the deposition process and a high amount of anatase is suitable for the pollutants degradation. Suspension plasma spraying permitted to retain the original anatase phase and allowed the elaboration of very active titanium surfaces for the nitrogen oxides decomposition.