Comparative study of spectroscopic and cyclic voltammetry properties of CuONPs from citrus peel extracts

This work presents synthesized nano-sized particles of copper oxide nanoparticles (CuONPs) from three different citrus peels extract. The as prepared nano sized crystalline particles were characterized with UV-Vis, FTIR, Zeta potential, XRD, cyclic voltammetry (CV) and TEM. The UV spectra of CuONPs from grape (GPE), lemon (LPE) and orange (OPE) peel extracts showed maximum absorption peaks at 320 nm, 326 nm and 337 nm respectively. The energy band gaps were calculated to be 2.78 eV, 2.74 eV and 2.23 eV for CuONPs/GPE, CuONPs/LPE and CuONPs/OPE respectively. The average crystalline spherical sizes for CuONPs from TEM were found to be 5.13 +/- 0.67 nm, 3.92 +/- 0.55nm and 4.63 +/- 0.7 nm for CuONPs/GPE, CuONPs/LPE and CuONPs/OPE respectively. The comparative CV studies of the bare screen print electrode (SPE) and the modified SPE with CuONPs from the peel extracts GPE, LPE and OPE respectively, showed that the green synthesized NPs are good catalyst with pronounced current response as compared to the bare SPE in the order CuONPs/GPE, CuONPs/OPE and CuONPs/LPE. The result reveal that the CuONPs from GPE has the best electrocatalytical properties, and suggesting that the synthesized CuONPs can be used in electrochemical sensor fabrication.