Electrospun Co₃O₄nanofibers as potential material for enhanced supercapacitors and chemo-sensor applications

In this paper, highly dense and defined Co3O4 nanofibers were prepared by electrospinning method followed by controlled oxidation using polyvinylpyrrolidone (PVP) and CoCl2 as precursors. For the fabrication of effective electrochemical sensors and supercapacitors, the prepared Co3O4 nanofibers were used as electro-active electrodes. The prepared Co3O4 nanofibers were morphologically investigated by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) which confirmed the formation of highly dense and well-defined fibrous morphology. The X-ray diffraction (XRD) and elemental analysis demonstrated the typical crystalline cubic phase Co3O4 with appropriate stoichiometric element ratio. The supercapacitor with prepared Co3O4 nanofibers based electrode has an excellent cycle stability and a considerably higher specific capacitance of 419 C/g at a current density of 0.5 A/g. Interestingly, the fabricated supercapacitor device keeps 87% capacitance after 5000 charge/discharge cycles. For 2-butanone chemical sensing, the prepared Co3O4 nanofibers based electrode presents a reasonable sensitivity of 90.7 mAμM-1cm-2 and linear dynamics of 10-200 μM with good LOD of ∼5.8 μM and regression coefficient (R) = ∼0.97407. Thus, the prepared Co3O4 nanofibers with highly porous surface would pave the direction to the manufacturing of efficient energy storage and electrochemical sensing materials.