Cu@SiO2 nanowires: synthesis, cathodoluminescence and SERS response

Abstract

Various shapes of Cu@SiO₂ nanowires were fabricated on a Cu substrate via simple thermal evaporation of SiO within a high-frequency induction furnace. The morphology and structure of the Cu@SiO₂ nanowires were characterized by using SEM, TEM, EDS and EDX elemental mapping. The morphology and density of the nanowires are controllable by adjusting the substrate temperature. The Cu cores are chemically stable due to the protection of the SiO₂ shell. The surface-enhanced Raman scattering (SERS) experiment on the shell-isolated nanowires showed excellent detecting performance compared with the bare Cu substrate. The cathodoluminescence (CL) investigation reveals that red, green and blue light emission was observed in the Silica sheath simultaneously. The as-synthesized samples have potential application in long acting and ultrasensitive SERS substrates and white light sources.