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

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.