Hierarchical NiCo2O4/NiO mixed nanofibers for enhanced supercapacitor and ammonia gas sensor applications.

Graphical representation of NiO, NCO and NCO/NiO NFs synthesization. [Display omitted] • NCO/NiO NFs, nanocomposites were synthesized via a facile electrospun and solvothermal method for a future electrode material of supercapacitor. • The NCO/NiO NFs having quick signal transfer in gas sensing and have high specific capacitance (1007 Fg−1) and good cyclic performance (92%). • Ammonia gas sensing performance of NCO/NiO NFs was measured, and the fast response and recovery times were found and are 32 s and 34 s, respectively. • NCO/NiO NFs nanocomposite materials could be utilized for constructing of good solid-state supercapacitors and gas sensing devices. In the present study, we investigated the NiCo 2 O 4 /NiO (NCO/NiO) composite nanofibers (NFs) synthesized via a facile electrospinning and solvothermal method as a future electrode material. The synthesized samples are characterized and their electrochemical and gas sensing properties are investigated. The morphology, structural, asymmetric vibrations and elemental compositions in the prepared samples are studied by Field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), Raman spectroscopy, Energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). The prepared NCO/NiO NFs exhibit high specific capacitance (1212 Fg−1) and good cyclic performance (94%), showing promising supercapacitor properties. For NCO/NiO NFs, the continuity of the structure contributes to rapid signal transmission in gas detection. Ammonia gas measurement of NCO/NiO NFs operated at 100 °C showed fast response and recovery times of 17 and 11 s, respectively. [ABSTRACT FROM AUTHOR]