Core-shell-structured CuO@Ni-MOF: bifunctional electrode toward battery-type supercapacitors and oxygen evolution reaction

This study is to develop a core–shell-structured copper oxide @ nickel metal organic framework ([email protected]) electrocatalyst over copper foam. The developed electrode is characterized by various tools such as X-ray diffraction, Fourier transform infrared spectrometry, and Raman spectrometry. Moreover, morphology and electronic structure studies are carried out for conformational analysis of the developed electrodes. Finally, the [email protected] electrode is used in multitasking, such as supercapacitors and oxygen evolution reaction. For supercapacitor application, the developed positive electrode in three-electrodes electrochemical cell delivered higher specific capacitance (Csp) of 1455.75 F/g at 3 A/g and excellent rate cycle ability of 78%. For the negative electrode, pistachio-derived activated carbon (PAC) was synthesized, aiming toward bio-based material, where PAC-18 exhibited a higher specific capacitance of 474.68 F/g at 2 A/g current density. These electrochemical properties made [email protected] and PAC-18 suitable for supercapacitor fabrication. Asymmetric battery type bio-based supercapacitor is fabricated with the structure of [email protected]∣∣solid state electrolyte∣∣PAC-18 in Swagelok cell. The fabricated bio-based supercapacitor revealed an energy density of 18 W h/kg and power density of 750 W/kg with good stability of 94% Csp retention even after 5,000 cycles of charge and discharge. For widening application of developed [email protected] electrode, oxygen evolution reaction in the alkaline condition is studied, and [email protected] delivered over potential as low as 300 mV with excellent stability.