A self-cleaning solution based on sol-gel and hydrothermal processes was applied to prepare the self-cleaning Fe/TiO2 surfaces on a ceramic substrate using the cold spray method. Moreover, a numerical method was employed to investigate the effect of spraying operation conditions, including carrier gas pressure, the standoff distance, and traverse speed on the coated layer thickness. Seven samples were prepared under different spray operating conditions. The results indicated that as the pressure increases from 2 to 4 bar, the average film thickness increases from 1.7 to 5.5 μm. In addition, when traverse speed rises to 1.8 cm/s, the surface coating substantially becomes thinner to <2 μm. Besides, it was observed that the coating thickness has the maximum value at a certain standoff distance between the spray gun and the substrate surface. Finally, the results were compared with those of the numerical simulation, properly consistent with a maximum relative error of <5%. Besides, the photocatalytic decomposition rate of formic acid by the coated surface at the spray pressure of 4 bar, the traverse speed of 1.2 cm/s, and the standoff distance of 10 cm was >94%. Additionally, the antibacterial tests showed a high potent surface activity against S. aureus and E. coli. Bacteria. Consequently, the proposed optimum condition was proved to be appropriate for preparing self-cleaning coatings.
