Abstract
Copper is a promising alternative to conventional plasmonic materials, though its practical use is hindered by a strong tendency to oxidize. Through systematic analysis of its vibrational, optical, morphological, structural, and surface potential properties, we confirmed the stability of copper (Cu) particles and highlighted the role of functional groups in modulating their oxidation susceptibility. Oxidation kinetics at 150 °C, in the presence of antioxidants and capping agents, as well as long-term colloidal stability, appear closely tied to the degradation of these stabilizers, which correlates with particle aggregation. Notably, precursor chemistry significantly affects oxidation behavior. Varying concentrations of polyvinylpyrrolidone (PVP) demonstrate a positive correlation with particle size control and thermal stability, indicating that PVP enhances oxidation resistance under the tested conditions. Our findings underscore most importantly the metallic phase's stability after exposure to air at a temperature of 150 °C, drawing attention to a possible precursor and capping agent combination that can result in oxidation-stable Cu particles, positioning them as cost-effective candidates for replacing more expensive plasmonic metals across diverse applications.