Copper-enhanced TiO2 nanostructured thin films: Structural, chemical, and antibacterial properties

Abstract

In this study, titanium was evaporated via e-beam glancing angle deposition in order to obtain nanostructured thin films. Additionally, copper (Cu) nanoparticles (NPs) were electrochemically deposited on top of them. Comprehensive structural analysis showed that the thin film, with a thickness of around 370 nm, consists of slanted columns with an average diameter of 7 nm, while copper nanoparticles range in size from 19 nm to 180 nm. A detailed chemical examination revealed that the deposited thin film contained TiO<inf>2</inf>, Ti<inf>2</inf>O<inf>3</inf>, and TiO phases, where TiO<inf>2</inf> is identified as the dominant phase in the sample, while the Cu nanoparticles are composed of metallic Cu and Cu<inf>2</inf>O. This research intended to evaluate the effect of Cu NPs on the antibacterial activity of TiO<inf>2</inf> thin films. Antibacterial tests were carried out on gram-positive Staphylococcus aureus and gram-negative Escherichia coli, Klebsiella aerogenes, and Pseudomonas aeruginosa. The obtained results show that copper nanoparticles improve the inhibition of gram-positive bacterial growth.