Electrochemical studies of nickel oxide nanoparticles via solution combustion method using green and chemical fuels

Abstract

The efficient manufacture of nickel oxide nanoparticles (NiO NPs) using a novel solution combustion method that makes use of chemical (glucose) and green (Aloe vera gel extract) fuels is reported in this work. As revealed by electron microscopy, the synthesized samples were spongy, spherical, agglomerated, and porous; in contrast, the face-centered cubic crystal structure (FCC) phase for NiO NPs was corroborated by PXRD. The energy band gaps of NiO NPs are 4.09 and 4.21 eV. Using an eco-friendly NiO electrode, cyclic voltammetry investigations demonstrated good reversibility (a reduced value of EO-ER). Its great conductivity was confirmed by electrochemical impedance tests, which also showed a low charge-transfer resistance. Using NiO NPs, stable electrode materials for application in supercapacitors can be readily created. In comparison to chemically synthesized NiO green generated NiO in a 3-electrode setup demonstrated a capacitance of 156 Fg−1 and 183 Fg−1 at a scan rate of 5 Ag−1, respectively, according to the GCD investigation. It also had good cycling stability, retaining more than 85% of its original capacitance after 2000 cycles. The results suggest that green produced NiO could be a cheap and practical material for use in supercapacitor applications in the future.

Keywords

• Aloe vera extract
• Photocatalyst
• Cyclic voltammetry
• Electrochemical impedance spectroscopy
• Supercapacitor