Controlled Synthesis of CuO Nanoparticles Using Sol-Gel Auto-Combustion Technique and Their Application in Super-capacitors

Abstract

Background: Copper oxide (CuO) nanoparticles hold potential in super-capacitor applications because they exhibit the pseudo-capacitive behavior and are relatively inexpensive. Sol-gel auto-combustion route provides an easy and effective pathway of producing CuO nanoparticles with a controlled size and morphology, which directly affect their electrochemical activity.

Purpose: This paper will synthesize CuO nanoparticles through the sol-gel auto-combustion method and test their electrochemical characteristics to use in supercapacitors.

Procedure: CuO nanoparticles were prepared by dissolution of copper nitrate in deionized water, and the fuel is added (citric acid). The mixture was heated, resulting in the auto-combustion to produce CuO. The X-ray diffraction (XRD), BET surface area analysis, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were used to characterize the nanoparticles. The electrochemical performance was evaluated through cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) as well as cycling stability.

Findings: The CuO nanoparticles produced showed high specific capacitance of 160 F/g at 10 mV/s, and had good cycling performance (82.4% retention after 1000 cycles). The XRD was used to determine that the CuO is in the monoclinic phase with an average crystallite size of 23.8 nm. The BET analysis revealed that there was an increment in surface area following the calcinations.

Conclusion: CuO nanoparticles prepared by the sol-gel auto-combustion method have good electrochemical characteristics and can become a promising material to use in energy storage.