Synthesis and characterization of copper oxide nanoparticles by microwave and modified carbon paste electrode with synthesized nanoparticles as a sensor for determination of ascorbic acid

Microwave irradiation as a heating method has found a number of applications in chemistry. The microwave synthesis, which is generally quite fast, simple, and energy efficient, has beendeveloped, and widely used for nanoparticles and ceramic materials, etc. Compared with conventional method, microwave synthesis has the advantages of very short time, small particle size, narrow particle size distribution, and high purity. In this study, copper oxide nanoparticleswere prepared by microwave irradiation of copper nitrate solution in basic medium. The effect of irradiation time and microwave radiation power on the final morphology of nano-CuO obtained through the microwave assisted technique has been investigated. The characterization of thesamples has been carried out by scanning electron microscopy (SEM) and powder X-ray diffraction (XRD). The results showed the best morphology was obtained at 540W and 2 min. Then The electrochemical behavior of oxalic acid is investigated on the surface of a carbon-pasteelectrode modified with CuO nanoparticles. Cyclic voltammetry study of the modified electrode indicated that the anodic peak current was enhanced by 2.5 fold in comparison to the non modified electrode and the current was due to diffusion process. The electrochemical behaviorwas further described by characterization studies of pH, scan rate and concentration of ascorbic acid. The CuO-carbon paste electrode has a limit of detection of 22 μM with linear range between 0.075 to 10 mM. Also good reproducibility and recovery was obtained when determining the presence of ascorbic acid in real sample.

Keywords:

Microwave , Nanoparticles of CuO , Cyclic voltammetry , ascorbic acid