Tuning the crystallinity of TiO2 coatings synthesized by an atmospheric pressure dielectric barrier discharge in a single step process

Titanium dioxide in its anatase form is of significant interest nowadays due to numerous properties such as biocompatibility, photoactivity under ultraviolet irradiation, or corrosion resistance. In this paper, titanium dioxide (TiO2) films are synthesized with a controlled substrate temperature going up to 673 K. Crystalline anatase was synthesized in a low power atmospheric pressure dielectric barrier discharge in a single step process. The effect of deposition parameters (plasma gas, the voltage input, precursor flow, deposition time, and substrate temperature) on the crystal size, crystallinity, and coating morphology was studied. It shows that the crystal size can be tuned, that the layers can have a transition from hydrophilicity to hydrophobicity, and that the coating morphology can be modified by optimizing these parameters. Finally, it is found that crystalline anatase TiO2 can be grown at a substrate temperature as low as 523 K in an atmospheric pressure plasma enhanced chemical vapor deposition process.