In Situ Repair and Reconstruction of Copper Surface Enhanced Its Anti-Oxidation Properties and Stability for Deep Learning-Powered Anti-Counterfeiting Labels.

Abstract

The in situ repair of oxidized copper (Cu) surfaces while constructing a superior protective layer is critical for sustainable development and the efficient utilization of metallic materials. Here, a simple solvothermal treatment is presented to repair oxidized Cu surfaces (Cu foils, nanowires, and nanocubes) and reconstruct an antioxidant layer with an ordered (111) crystal-plane (Cu-SC) in situ. Electrochemical measurements reveal that the corrosion rate of Cu-SC in 0.1 m NaOH is reduced to 1.99 × 10^-3 mm yr^-¹, a fivefold improvement over pristine Cu (1.00 × 10^- ² mm yr^-¹). Density functional theory calculations confirm that the reconstructed (111) surface reduces oxygen molecule adsorption, significantly hinders oxygen atom diffusion into the bulk and continuous adsorption on surface. Anti-counterfeiting labels fabricated from Cu-SC nanowires exhibit exceptional durability, retaining reliable authentication accuracy after 144 h at 85 °C/85% relative humidity and 2000 bending cycles. The enhanced anti-oxidation properties of Cu-SC ensure the stability of its microstructures, which are critical for deep learning-based authentication, allowing precise feature extraction and accurate label verification even under extreme conditions. These results highlight the potential of (111) surface reconstruction for enhancing material stability, enabling advanced anti-counterfeiting applications, and promoting the sustainable utilization of metallic materials.