A silver nanoparticle loaded TiO2 nanoporous layer for visible light induced antimicrobial applications

• A nanoporous TiO2 layer with an average pore size of 65 nm was formed on titanium.
• Ag nanoparticles were loaded into the nanoporous TiO2 layer by UV light irradiation.
• The active surface area of TiO2 in alkaline medium was enhanced by Ag loading.
• The Ag loaded TiO2 layer showed visible light absorption at around 350–550 nm.
• The Ag-TiO2 layer showed antibacterial activity against Bacillus sp. under visible light.

A nanoporous TiO2 layer was formed on commercially pure titanium by a simple anodization method in aqueous hydrofluoric acid (HF) medium. Silver nanoparticles (AgNP) were loaded into the nanoporous TiO2 layer by UV light irradiation. The morphology, chemical composition and photocatalytic activity of the modified titanium surfaces were characterized by scanning electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy and UV–vis absorption spectroscopy techniques. The redox behavior of the AgNP loaded TiO2 layer was analyzed by cyclic voltammetry (CV) studies. The impedance behavior of the nanoporous TiO2 layer with and without AgNP was investigated by electrochemical impedance spectroscopy (EIS). The antibacterial effect of the AgNP loaded TiO2 layer was evaluated using Pseudomonas sp. and Bacillus sp. cultures. The efficacy of this modified layer to act as an antibacterial agent to minimize biofouling of titanium is demonstrated in this investigation.