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.