Enhancing Antibacterial Properties and Biosafety Evaluation of TiO₂/Cu Photocatalytic Coatings Through Suspension Flame Spraying

This paper describes the preparation of TiO2/Cu photocatalytic coatings using the suspension flame spraying technique. The composite coatings maintain the metallography phases of the original powder material. The thickness of the coating increases as the Cu content increases. And the antibacterial property of the coatings is significantly improved with the addition of Cu. The results indicate that the photo-response of the TiO2/Cu coatings is significantly enhanced as the Cu content increases in the coatings within the range of visible light. The composite coatings exhibit high antibacterial properties against gram-positive Staphylococcus epidermidis and gram-negative Escherichia coli, with the antibacterial rate reaching 99.9%. The improved antibacterial performance is attributed to the dual action of enhanced photocatalysis of TiO2 and Cu release. In addition, the toxicity of the coatings is analyzed in vitro using mouse fibroblast cell experiments. The results show that the coatings have some toxicity to cells, which serves as a warning for the subsequent modification of TiO2 and provides a new research direction.