Square-Facet Nanobar MOF-Derived Co3O4@Co/N-doped CNT Core-Shell-based Nanocomposites as Cathode Materials for High-Performance Supercapacitor Studies

Swapnajit V Mulik; Suprimkumar D Dhas; Annasaheb V Moholkar; Vinayak G Parale; Hyung-Ho Park; Pramod A Koyale; Vijay S Ghodake; Dillip K Panda; Sagar D Delekar

doi:10.1021/acsomega.2c06369

Square-Facet Nanobar MOF-Derived Co₃O₄@Co/N-doped CNT Core-Shell-based Nanocomposites as Cathode Materials for High-Performance Supercapacitor Studies

ACS Omega. 2023 Jan 4;8(2):2183-2196. doi: 10.1021/acsomega.2c06369. eCollection 2023 Jan 17.

Authors

Swapnajit V Mulik¹, Suprimkumar D Dhas², Annasaheb V Moholkar², Vinayak G Parale³, Hyung-Ho Park³, Pramod A Koyale¹, Vijay S Ghodake¹, Dillip K Panda⁴, Sagar D Delekar¹

Affiliations

¹ Department of Chemistry, Shivaji University, Kolhapur416 004, Maharashtra, India.
² Thin Film Nanomaterial, Department of Physics, Shivaji University, Kolhapur416 004, Maharashtra, India.
³ Department of Materials Science and Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul03722, South Korea.
⁴ Department of Materials Science and Engineering, Clemson University, Clemson, South Carolina29631, United States.

Abstract

The binary as well as ternary nanocomposites of the square-facet nanobar Co-MOF-derived Co₃O₄@Co/N-CNTs (N-CNTs: nitrogen-doped carbon nanotubes) with Ag NPs and rGO have been synthesized via an easy wet chemical route, and their supercapacitor behavior was then studied. At a controlled pH of the precursor solution, square-facet nanobars of Co-MOF were first synthesized by the solvothermal method and then pyrolyzed under a controlled nitrogen atmosphere to get a core-shell system of Co₃O₄@Co/N-CNTs. In the second step, different compositions of Co₃O₄@Co/N-CNT core-shell structures were formed by an ex-situ method with Ag NPs and rGO moieties. Among several bare, binary, and ternary compositions tested in 6 M aqueous KOH electrolyte, a ternary nanocomposite having a 7.0:1.5:1.5 stoichiometric ratio of Co₃O₄@Co/N-CNT, Ag NPs, and rGO, respectively, reported the highest specific capacitance (3393.8 F g^-1 at 5 mV s^-1). The optimized nanocomposite showed the energy density, power density, and Coulombic efficiency of 74.1 W h.kg^-1, 443.7 W.kg^-1, and 101.3%, respectively, with excellent electrochemical stability. After testing an asymmetrical supercapacitor with a Co₃O₄@Co/N-CNT/Ag NPs/rGO/nickel foam cathode and an activated carbon/nickel foam anode, it showed 4.9 W h.kg^-1 of energy density and 5000.0 W.kg^-1 of power density.