Urchin-like NiCo2O4 microsphere by hydrothermal route: Structural, electrochemical, optical and magnetic properties

Abstract

Urchin-like microsphere of NiCo2O4/NIC sample was synthesized by hydrothermal method, followed by post annealing treatment at 400 �C for 3 h. The phase confirmation and surface morphology was analyzed by XRD, FESEM and Raman spectroscopy, which shows that cubic spinel structure with Fd3m space group supporting the microstructure. The elemental mappings were characterized by EDS analysis. The electrochemical performance revealed that the prepared NIC sample exhibits specific capacitance of 295Fg?1 at 20 mV?1 owing to its high surface area; consist of interconnection of nanopores between the subunit of nanoneedle inside the urchin like microsphere. The optical band gap energy was estimated by using Tauc plot, are 2.17eV and 3.5eV respectively. This result well consistent with the theoretical investigation by using DFT calculation. Furthermore a significant M-H loop revealed that, NIC system shows ferromagnetic behavior at RT. Hence all the combined experimental and theoretical results provide to design synergetic microstructure of NIC system for multifunctional application. � 2019 Elsevier Ltd and Techna Group S.r.l.