Formation and Antibacterial Mechanisms of Micro-Arc Oxidation Coatings on Ta2 Pure Titanium by Doping with Cu2O Nanoparticles

Cu2O nanoparticles (0–4 g/L) were incorporated into the electrolyte to fabricate coatings on TA2 pure titanium via micro-arc oxidation. The effects of different Cu2O nanoparticle concentrations on the microstructure, antibacterial performance, formation, and antibacterial mechanisms of the coatings were investigated. Microstructural characterization indicated that Cu2O nanoparticles were incorporated into the coating through the combined action of electrophoretic forces and micro-discharges. At 4 g/L Cu2O, the incorporation of Cu2O nanoparticles shifted from uniform incorporation to particle aggregation. Compared with coatings fabricated using 1 and 2 g/L Cu2O nanoparticles, those fabricated using 3 and 4 g/L exhibited superior antibacterial efficacy. Copper ion release was the primary antibacterial mechanism. Micro-arc oxidation coatings modified with 3 g/L Cu2O nanoparticles achieved the best compromise between microstructural uniformity and antibacterial performance among the tested concentrations.