Visible Light-Driven Photocatalysis and Antibacterial Performance of a Cu-TiO₂ Nanocomposite

A Cu-TiO₂ nanomaterial with unique antibacterial and photocatalytic properties is introduced in this study. Cu-TiO₂ nanocomposites were obtained using an adapted direct current magnetron sputtering apparatus, where TiO₂ anatase nanoparticles (NPs) were used as the substrates and copper as the sputtering target. The obtained powder was characterized by physical and chemical methods. Copper was deposited on TiO₂ NPs for 30 and 60 min, resulting in two samples with different copper contents of 3 and 5 wt %, respectively. The photocatalysis test evaluated the degradation of rhodamine B (RhB) dye under a specific wavelength (405 nm LED) and a complete degeneration occurred in 120 min, ∼ 33% faster when compared to pristine TiO₂. The antibacterial assays were performed for <i>Escherichia coli</i> and <i>Staphylococcus aureus</i> in dark and visible-light conditions, using a 405 nm LED and a wide-spectrum white LED, reaching an inactivation of 99.9999% for both bacteria. The magnetron sputtering is an ecofriendly way to form heterojunctions with photocatalytic and bactericidal properties in the absence of wet chemical methods or residues. This work may open new pathways for enhancing the fungicidal and virucidal activities of nanocomposites under the action of visible light.