Ceramic tiles coated with Zr-Ag co-doped TiO2 thin film for indoor air purifying and antimicrobial applications

In this study, Zr-Ag co-doped TiO2 (ZAT) photocatalyst films having varied
numbers of layers (1, 2, 3, and 4) have been developed to coat on ceramic
tile substrates by sol-gel spin coating technique. The specimens were tested to
determine antibacterial activity against Escherichia coli and the capability to
degrade gaseous formaldehyde under visible light. X-ray diffraction, ultraviolet
and visible absorption spectroscopy, water contact angle, and scanning electron
microscopy were applied to characterize the structural and morphological properties
of the samples. The photocatalytic reactivity of the nanocomposite films
was investigated by the decolorization of methylene blue (MB) dye under visible
light irradiation. The results showed that the two-layer ZAT photocatalyst film
on ceramic tile exhibited the highest photocatalytic decolorization of MB, with
60.36% efficiency. The ZAT tile had formaldehyde degradation efficiency up to
32.74% within only 6 h under visible light irradiation, higher than that of the
bare ceramic tile (4.90%). Additionally, the ZAT thin films could enhance anti-E.
coli activity and could be capable of degrading air pollution.