Green synthesis of copper oxide nanoparticles using neem leaf extract (Azadirachta indica) for energy storage applications

ABSTRACT

The green synthesis method was utilised in synthesising copper oxide nanoparticles from Azadirachta indica using copper sulphate as the precursor at different molarities. The nanoparticles were investigated using X-ray diffractometry (XRD), Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), UV-Vis spectrophotometry, and potentiometry to understand their respective structural, morphological, elemental, optical, and electrochemical properties. Crystalline diffraction peaks with nanospheres distributed through the surface. The elemental compositions of the as-deposited elements were confirmed from the EDX spectra. High optical absorbance and energy band gap values ranging from 1.75 eV to 2.72 eV at increasing molarities were obtained. Good cyclic voltammograms measured at a scan rate of 20 mV/s yielded a maximum specific capacitance of 148 F/g. The synthesised nanoparticles would find useful applications in supercapacitors and electrochemical devices.

GRAPHICAL ABSTRACT

KEYWORDS:

• Copper oxide
• nanoparticles
• green synthesis
• neem extract
• specific capacitance

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Data will be made available by authors upon reasonable request.

Research highlights

• Green synthesis of CuO nanoparticles from neem leaf extract..

• Crystalline particles with nano spherical morphology.

• Good optical absorbance with band gap energy ranging from 1.75eV to 2.72eV.

• Cyclic reversibility with a maximum specific capacitance of 148 F/g.

• Potential application in supercapacitors and electrochemical devices.