Facile growth of binder-free Co3O4@FNF electrode with superior electrochemical performance for energy storage and sensing applications

Abstract

Herein, we present a quick and cost-effective electrodeposition method to synthesize binder-free cobalt oxide (Co₃O₄) nanostructures. The structural crystallinity of the prepared electrodes was examined using X-ray diffraction (XRD), while Fourier-transform infrared spectroscopy (FTIR) was used to study the stretching and bending vibrations of metal–oxygen bonds. Scanning electron microscopy (SEM) revealed that as the concentration increased from 1 mM, nanoparticles transitioned from agglomeration to sheet formation. The supercapacitor properties of these Co₃O₄ nanostructure electrodes were investigated in a 6 M KOH solution. Among the electrodes, Co₃O₄@FNF-1 exhibited the highest capacitance of 1444 F g⁻¹ at a current density of 0.5 A g⁻¹. Additionally, the optimized Co₃O₄@FNF-1 electrode demonstrated 96% stability after 8000 cycles and showed excellent glucose sensing capabilities. These findings suggest that the binder-free Co₃O₄ electrode is a promising candidate for high-performance supercapacitor and biosensing applications.