Electrochemical bulk synthesis and characterisation of hexagonal-shaped CuO nanoparticles

Abstract

A simple and efficient two-step hybrid electrochemical–thermal route was developed for the bulk synthesis of CuO nanoparticles using aqueous sodium nitrate electrolyte and Cu electrodes in an undivided cell under galvanostatic mode at room temperature. The influence of electrolyte concentration on the synthesis of CuO nanoparticles was studied at 1.0 A/dm2 current density. Electrochemically generated precursor was calcined for an hour at different levels of temperature in the range 200–900°C. The calcined samples were characterised by XRD, TG-DTA, XPS, SEM/EDAX, TEM, FT-IR and UV–Vis spectral methods. The crystallite sizes were estimated and the thermal behaviour of as-prepared compound was examined. Rietveld refinement of X-ray data shows results matching the monoclinic structure with the space group of C2/c (no. 15). The TEM result revealed that the particle sizes were in the order of 30–50 nm diameter and 120–200 nm length. The blue shift was noticed in UV–Vis absorption spectra. All samples of CuO exhibited randomly oriented hexagonal morphology.