Ag doped Co3O4 nanoparticles for high-performance supercapacitor application

Asab Fetene Alem; Ababay Ketema Worku; Delele Worku Ayele; Tessera Alemneh Wubieneh; Alebel Abebaw Teshager; Tadele Mihret Kndie; Bimrew Tamrat Admasu; Minbale Admas Teshager; Addisu Alemayehu Asege; Mehary Dagnew Ambaw; Misganaw Alemu Zeleke; Alemayehu Kifle Shibesh; Temesgen Atnafu Yemata

doi:10.1016/j.heliyon.2023.e13286

Ag doped Co₃O₄ nanoparticles for high-performance supercapacitor application

Heliyon. 2023 Jan 31;9(2):e13286. doi: 10.1016/j.heliyon.2023.e13286. eCollection 2023 Feb.

Authors

Affiliations

¹ Bahir Dar Energy Center, Bahir Dar Institute of Technology, Bahir Dar University, P.O. Box 26, Bahir Dar, Ethiopia.
² Department of Chemistry, College of Science, Bahir Dar University, P.O. Box 79, Bahir Dar, Ethiopia.
³ School of Materials Science and Engineering, Bahir Dar University, P.O. Box 79, Bahir Dar, Ethiopia.
⁴ Faculty of Chemical and Food Engineering, Bahir Dar Institute of Technology-Bahir Dar University, P.O. Box 26, Bahir Dar, Ethiopia.
⁵ Faculty of Mechanical Engineering, Bahir Dar Institute of Technology-Bahir Dar University, P.O. Box 26, Bahir Dar, Ethiopia.
⁶ Department of Industrial Chemistry, College of Science, Bahir Dar University, P.O. Box 79, Bahir Dar, Ethiopia.

Abstract

Ag doped Co₃O₄ nanoparticles (NPs) were synthesized via a co-precipitation method changing the concentration of Ag. The crystal structure, morphology, surface area, functional group, optical band gap, and thermal property were investigated by XRD, SEM, BET, FTIR, UV-Vis, and TGA/DTA techniques. The XRD results showed the formation of single-cubic Co₃O₄ nanostructured materials with an average crystal size of 19.37 nm and 12.98 nm for pristine Co₃O₄ and 0.25 M Ag-doped Co₃O₄ NPs. Morphological studies showed that pristine Co₃O₄ and 0.25 M Ag-doped Co₃O₄ NPs having a porous structure with small spherical grains, porous structures with sponge-like structures, and loosely packed porous structures, respectively. The pristine and 0.25 M Ag-doped Co₃O₄ NPs showed BET surface areas of 53.06 m²/g, and 407.33 m²/g, respectively. The band gap energy of Co₃O₄ NPs were 2.96 eV, with additional sub-bandgap energy of 1.95 eV. Additionally, it was discovered that the band gap energies of 0.25 M Ag-doped Co₃O₄ NPs ranged from 2.2 to 2.75 eV, with an extra sub-band with energies ranging from 1.43 to 1.94 eV for all as-prepared samples. The Ag-doped Co₃O₄ as prepared samples show improved thermal properties due to the doping effect of silver. The CV test confirmed that the 0.25 M Ag-doped Co₃O₄ NPs exhibited the highest specific capacitance value of 992.7 F/g at 5 mV/s in a 0.1 M KOH electrolyte solution. The energy density and power density of 0.25 M Ag-doped Co₃O₄ NPs were 27.9 W h/kg and 3816.1 W/kg, respectively.

Keywords: Co-precipitation method; Cobalt oxide; Doping; Nanoparticles; Supercapacitor.