Simultaneous electro-generation and electro-deposition of copper oxide nanoparticles on glassy carbon electrode and its sensor application

Abstract

Copper oxide nanoparticles (CuO) were electro-generated and electro-deposited simultaneously on the glassy carbon electrode (GCE) using cyclic voltammetry at a reduction potential of - 1.4 V to - 0.2 V in 0.1 M NaOH and 1.67 mM CuCl solution. The electrodeposited CuO nanoparticles show an excellent electro- catalytic activity towards the detection of potassium ferricyanide. The scan rate, concentration of the analyte and pH of the solution were varied accordingly to study the stability of the copper oxide deposited glassy carbon electrode (CuO/GCE). The CuO/GCE electrode shows amazing stability, charge transfer and reproducibility even at low concentration of the analyte. The cyclic voltammetry is proved to be one of the convenient methods to reduce the precursors into metal oxide nanoparticles just by applying suitable current. The main advantage of this method is uniform deposition of CuO nanoparticles on GCE and thus increases the number of active sites, surface area and electro-catalytic properties. Scanning electron microscopy (SEM) was used to study the morphology of the electro-generated CuO nanoparticles. The zeta-potential analysis was carried out to study the surface potential of charged CuO nanoparticles and it was found to be + 58.29 mV. Further, CuO nanoparticles were characterized by X-ray diffraction to study the phases. UV-visible spectroscopy depicts the absorption peak at 288 nm confirms the formation of CuO nanoparticles. This absorption is attributed by the electronic transition from valence band to conduction band due to the quantum size of the particles.