Highly stable localized surface plasmon resonance of Cu nanoparticles obtained via oxygen plasma irradiation

Copper nanoparticles (CuNPs) possess strong localized surface plasmon resonance (LSPR) in visible light. However, CuNPs are not chemically stable in air, which has seriously hindered the applications based on the LSPR of CuNPs. We developed an artificial method to passivate CuNPs as Al naturally does in air, preventing the oxidation of CuNPs through swift oxidation of the surface atoms