Unravelling the structure and electrochemical performance of Mo-Cu dual-doped NiO nanorod shaped electrodes for supercapacitor application

In this report, the hydrothermal method was adopted to prepare Mo-Cu dual-doped NiO nanorods. A single phase, with the face-centered cubic geometry was confirmed by an xray diffraction study in all the nanostructures. A drop in crystallite size with increasing Cu concentrations has a significant impact on the electrochemical performance. Scanning Electron Microscopy (SEM) revealed one-dimensional nanostructure, and the color map- ping ascertained the presence of all the incorporated dopants. The confirmation of grown nanorods was ascertained by high-resolution transmission electron microscopy (HRTEM). The electrochemical analysis revealed the pseudocapacitive nature based on the faradaic redox mechanism. A maximum specific capacitance of 1136 F/g was obtained at a 2 mV/s scan rate for Ni1.9Mo0.08Cu0.02O nanorods. The galvanostatic charge-discharge (GCD) analysis carried out at various current densities (1-8 Ag-1), established that the Ni0.9- Mo0.02Cu0.08O electrode displays a maximum specific capacitance of 502 F/g at 1 A/g. The Electrochemical Impedance Spectroscopy (EIS) established the perfect capacitive nature in the low-frequency region, with non-uniform distribution of ions. In conclusion, the high specific capacitance (502 F/g) of Ni0.9Mo0.02Cu0.08O electrode at 1 A/g, with energy density (21.10 Wh/kg) and power density (3.44 kW/kg) make it a fascinating candidate for the en- ergy storage devices. (c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

In this study, Mo-Cu dual-doped NiO nanorods were prepared using the hydrothermal method. Characterization techniques including X-ray diffraction, scanning electron microscopy, and high-resolution transmission electron microscopy were employed to study the nanorods. Electrochemical analysis revealed their pseudocapacitive nature and high specific capacitance under certain conditions.