Preparation and antibacterial activity of Ag-doped TiO2 coating on the porous surface of aluminum

Aluminum (Al) and its alloys have been widely used in daily life, but the absence of antibacterial properties makes them potential vectors for bacterial transmission. In this study, an Ag-doped TiO2 coating was successfully prepared on the porous surface of etched Al foil using the sol-gel method. The results indicated that the porous layer allowed the gel to permeate through the holes, thereby forming an interface carrying these antibacterial agents with a thickness of about 10 μm. The Ag dopant promoted the transformation of titania from rutile to anatase during the calcination process, with the rutile being absent when the atomic ratio of Ag to Ti reached 0.10. Meanwhile, the doped Ag+ was thermally decomposed into metallic Ag0. As a result, doping Ag enhanced the photocatalytic efficacy of TiO2 coating. Moreover, the antibacterial rate of this coating against Escherichia coli and Staphylococcus aureus under dark conditions could reach more than 99%, and the corrosion resistance of the Al foil was also slightly improved by it.