Self-Cleaning Surfaces with Superhydrophobicity of Ag–TiO₂ Nanofilms on the Floor Ceramic Tiles

Abstract—The goal of this study was the surface modification of industrial floor ceramic tiles by sol-gel dip coating method to improve the antibacterial and hydrophobicity activity of floor tiles. TiO₂ and Ag–TiO₂ nanofilms were prepared on floor tile. Ag–TiO₂ and TiO₂ films with different AgNO₃ and TiO₂ content were characterized by scanning electron microscopy X-ray diffraction, energy-dispersive X-ray spectroscopy and wettability to determine the topologies, microstructures, chemical compositions and cleanability, respectively. The results showed that, the wettability was significantly improved by increasing silver content comping with pure TiO₂. The antimicrobial effect of the synthesized nanofilm was carried out against Gram-negative and Gram-positive bacteria (S. aureus ATCC 6538 and E. coli ATCC 25922) respectively. The synthesized Ag–TiO₂ thin film showed enhanced bactericidal activities compared to the neat TiO₂ nano film both under visible light. Antibacterial properties increased with increasing of AgNO₃ from 0.1 to 0.2 wt % and the amount of S. aureus ATCC 6538 and E. coli ATCC 259 were reduced by 99 and 95%, individually. With comparing of all samples, it could be observed that, the percentage of reduction of S. aureus ATCC 6538 was higher than that of E. coli ATCC 259.