Abstract:

The electrodeposition of Cu layers were investigated in 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF₄) ionic liquid on ITO electrodes by constant potential method. The results indicate that Cu²⁺ undergoes two one-electron reduction processes, involving the transformation to Cu⁺ and the deposition of Cu. The XRD and SEM were employed to characterize the composition and surface morphology of the deposition layers, indicating that they were strongly depended on the applied potentials. The mixture nanoparticles of Cu and Cu₂O was obtained at relative positive potentials, while pure Cu layer was formed at extremely negative potentials. With negative movement of applied potentials, the surface layer became more compact and the morphology underwent a process from flower-like, rod-like to spherical particles. SERS detection of pyridine on the Cu layer was performed, suggesting its high activity and uniformity as a SERS substrate.

Key words: Ionic liquid, Cu nanoparticles layer, Electrodeposition, Surface enhanced Raman spectroscopy