Synthesis and Characterization of Cobalt Oxide nanoparticles by Electrochemical Reduction Method and Screening of their Antioxidant Activity

Abstract

The nanostructured cobalt oxides (Co3O4) were synthesized via the electrochemical reduction process by optimizing current density at 14 mA/cm2, CTAB was used as a structure directing agent in an organic medium consisting of acetonitrile and tetrahydrofuran in a 4:1 ratio. The synthesized cobalt oxide nanoparticles were characterized by using UV-visible spectroscopy, FTIR, XRD, SEM, EDS and TEM analysis techniques. The FTIR spectra shows strong absorption peaks at 520.78 and 653.87 cm-1 verified the existence of Co3O4 nanoparticles. The peak observed at 294 nm in UV spectrum confirms the nanoparticles were synthesized. The X-ray diffraction (XRD) pattern shows face centered cubic spinel structure (FCC) of the Co3O4 nanoparticles. Scanning electron microscopy investigation showed spherical and Quasi-spherical shape surface morphology of nanoparticles. The cobalt oxide nanoparticles particle size was 37.17 nm measured using transmission electron microscopy. Energy dispersive spectroscopy was used to determine the presence of the elements Co and O. The antioxidant activity of the synthesized nanoparticles was investigated spectrophotometrically using a modified 2,2-diphenyl-1-picryl-hydrazyl (DPPH) test. The results demonstrate that synthesized Co3O4 nanoparticles shows 70.89 % free radical scavenging within 60min and it can be suggesting their possible applications in pharmaceutical and food industries due to its high efficiency and low cost.