Interfacial engineering of nano-copper: mechanisms, strategies, and innovations for oxidation resistance

Nano-copper, characterized by its unique physicochemical properties such as high specific surface area, quantum size effects, and exceptional conductivity, has emerged as a pivotal material in advanced technologies. However, its susceptibility to oxidation under ambient conditions significantly compromises its performance and limits practical applications. This review systematically examines the oxidation mechanisms of nano-copper, emphasizing the roles of particle size, temperature, crystallographic orientation, and environmental factors (e.g., humidity and oxygen adsorption). Key findings reveal that oxidation follows distinct pathways in dry versus humid environments, with electrochemical corrosion accelerating degradation in the presence of moisture. To address these challenges, recent advancements in surface modification strategies are comprehensively reviewed. Coating technologies, including graphene encapsulation and carbon-based composites, demonstrate enhanced oxidation resistance by physically isolating nano-copper from reactive species. Core-shell architectures, such as Cu@Ni and Cu@Ag, leverage electronic shielding and interfacial engineering to improve stability. Functional group modifications (e.g., -SH and -COOH) and coordination layer designs (e.g., ligand complexes) achieve molecular-level control over surface passivation, while complexation methods utilize ligands for eco-friendly stabilization. Despite progress, challenges persist in achieving uniform shell layers, scalable fabrication, and long-term durability. Future research directions emphasize the development of low-cost, green synthesis techniques, atomic-scale interface engineering, and multifunctional nano-copper. Innovations such as dynamic coordination systems, self-healing coatings, and crystallographic orientation-specific modifications hold promise for expanding nano-copper's applicability in flexible electronics, catalysis, and biomedical fields. This review underscores the critical need for interdisciplinary approaches to translate laboratory-scale breakthroughs into industrial solutions, ultimately unlocking the full potential of nano-copper in next-generation technologies.