1 Department of Physics, Government College for Women Chintamani-563125 India.
2 Department of Science, School of Applied Sciences, REVA University Bangalore-64 India.
3 Department of Chemical and Materials Engineering, Gina Cody School of Engineering and Computer Science, Concordia University Montreal H3G 2W1 Canada.
4 Research Centre, Department of Chemistry, East West Institute of Technology Bangalore-91 India ravicr128@gmail.com.
5 Department of Chemistry, Ballari Institute of Technology and Management Bellary-583104 Karnataka India.
6 Department of Applied Sciences, Papua New Guinea University of Technology Lae Morobe Province 411 Papua New Guinea.
7 Department of Prosthodontics, Saveetha Dental College & Hospital, Saveetha Institute of Medical and Technical Science (SIMATS), Saveetha University Chennai 600077 Tamil Nadu India.

This study presents a new green solution combustion method (aloe vera gel extract as fuel) and chemical method (glucose as fuel) to synthesise Zn-doped nickel oxide nanoparticles (Zn:NiO NPs). The face centered cubic crystal structure (FCC) phase was validated by PXRD, while the produced samples' spongy, spherical, agglomerated, and porous characteristics were shown by electron microscopy. The energy band gap values of 4.21 eV and 4.09 eV, respectively, were deduced for green and chemically synthesized Zn:NiO NPs. The reversibility was demonstrated by cyclic voltammetry with a lower E_O-E_R value for the green-Zn:NiO electrode. The studies on electrochemical impedance confirmed strong conductivity for the NPs by demonstrating a low charge transfer resistance. The Zn:NiO NPs are easily convertible into a stable electrode material that may be used in supercapacitors. According to the findings, Zn:NiO is an economical and promising material for use in supercapacitors in the future.