Photocatalytic TiO2 on copper alloy for antimicrobial purposes

Autores: Chung, C.J.|Chiang, C.C.|Chen, C.H.|Hsiao, C.H.|Lin, H.I.|Hsieh, P.Y.|He, J.L.
Fuente: Applied catalysis
B 85 (1-2), 103-108
2009

Photocatalytic titanium dioxide (TiO2) has been developed and extensively applied due to its nontoxicity, high catalytic activity, and strong self-cleaning characteristics. The present study employs an arc ion plating technique to deposit a strongly adhered photocatalytic TiO2 coating onto bare Cu-35Zn substrate, which is commonly used in sanitary wares. The present report aims to create a TiO2 coating with antimicrobial function and satisfactory mechanical properties. The results indicate that arc ion plating can successfully deposit TiO2 onto brass substrates that are precoated with Ni/Cr. The cross-sectional morphology of TiO2 coating shows a fine and dense columnar structure of anatase with a growth rate of 5 mu m/h. The surface microhardness of the specimen deposited with TiO2 coating is 351.9 HV. The adhesive force of the coating is satisfactory with a critical load of 20.38 N and its wear resistance is far better than that of the brass substrate and Ni/Cr-precoated specimen. The coating–s wear index obtained from a Taber test is 0.26. TiO2 coatings can act as an ideal passive film and thereby shows a high corrosion potential and low corrosion current in aqueous sodium chloride. The photocatalytic effect of anatase TiO2 will be activated under the incident light with energy greater than the band gap energy Eg, of TiO2. (3.2 eV, 387.5 nm), thereby providing antimicrobial function. In general, the Ni/Cr-precoated specimen incorporated with a photocatalytic TiO2 film can provide sufficient protective and antimicrobial functions to its substrate, rendering it highly feasible for commercial use