Efficient antibacterial and microbial corrosion resistant photocatalytic coating: Enhancing performance with S-type heterojunction and Cu synergy

Microbial corrosion stands as a leading cause of deterioration in metallic materials, leading to substantial economic ramifications. Cu2O coatings, envisioned as potent photocatalytic antimicrobial solutions, offer a pathway to mitigate microbial corrosion. Nevertheless, inherent limitations such as photocorrosion and suboptimal charge separation efficiency hinder their broad adoption. This study introduces a novel, highly efficient antimicrobial 2D g-C3N4/Cu2O/Cu coating synthesized successfully. The ultrathin and porous structure of the 2D g-C3N4 substrate provides ample active sites for Cu2O and Cu deposition, enhancing current efficiency while bolstering light absorption and electron transfer capabilities. Additionally, the formation of an S-type heterojunction between 2D g-C3N4 and Cu2O/Cu effectively combats Cu2O photocorrosion. Notably, the coating demonstrates rapid elimination of Escherichia coli and Staphylococcus aureus within 1 h under both illuminated and dark conditions, owing to the synergistic bactericidal effects of copper ions and the generation of reactive oxygen species facilitated by the coating. Furthermore, significant inhibition of microbial corrosion on 316L stainless steel induced by Pseudomonas aeruginosa underscores the robust antimicrobial properties of the coating. Thus, this synergistic antimicrobial coating, fusing photocatalysis with copper, holds substantial promise in protecting metallic materials against microbial corrosion, meriting widespread application consideration.