Synthesis of NiMoO4/3D-rGO Nanocomposite in Alkaline Environments for Supercapacitor Electrodes

Shahrzad Arshadi Rastabi,Nicklas Blomquist,Håkan Olin,Manisha Phadatare,Fatemeh Dabir,Rasoul Sarraf Mamoory

doi:10.3390/cryst9010031

Abstract

Although Graphene oxide (GO)-based materials is known as a favorable candidate for supercapacitors, its conductivity needs to be increased. Therefore, this study aimed to investigate the performance of GO-based supercapicitor with new methods. In this work, an ammonia solution has been used to remove the oxygen functional groups of GO. In addition, a facile precipitation method was performed to synthesis a NiMoO4/3D-rGO electrode with purpose of using synergistic effects of rGO conductivity properties as well as NiMoO4 pseudocapacitive behavior. The phase structure, chemical bands and morphology of the synthesized powders were investigated by X-ray diffraction (XRD), Raman spectroscopy, and field emission secondary electron microscopy (FE-SEM). The electrochemical results showed that the NiMoO4/3D-rGO(II) electrode, where ammonia has been used during the synthesis, has a capacitive performance of 932 Fg−1. This is higher capacitance than NiMoO4/3D-rGO(I) without using ammonia. Furthermore, the NiMoO4/3D-rGO(II) electrode exhibited a power density of up to 17.5 kW kg−1 and an energy density of 32.36 Wh kg−1. These results showed that ammonia addition has increased the conductivity of rGO sheets, and thus it can be suggested as a new technique to improve the capacitance.

Highlights

Growing concerns about the serious environmental pollution and fossil-fuel energy crisis have attracted considerable attention to renewable and clean energy storage technologies [1].Lithium-ion batteries, sodium-ion batteries, and supercapacitors (SCs) are currently potential energy storage devices [2]
X-ray diffraction spectra of the samples were carried out at 2θ corresponded the (002), which indicates the of theGO
It can be concluded that the synergistic effect of the ammonia, metal ions and temperature benefited the deoxygenation of Graphene oxide (GO) sheets

Summary

Introduction

Lithium-ion batteries, sodium-ion batteries, and supercapacitors (SCs) are currently potential energy storage devices [2]. Various kinds of materials have been selected to improve electrode properties. Carbonaceous materials such as graphene and reduced GO can deliver high power density and possess high specific-area, good electrical conductivity, high chemical stability, and biocompatibility [6], faradaic electrode materials like metal oxides can provide higher capacitance and larger energy densities due to their redox reactions [7]. Binary nickel-based oxides have attracted tremendous research interest because of their high theoretical capacitance and excellent electrochemical activity [8], arising from their improved electronic conductivity and surface redox reactions. Among various pseudo-active materials, NiMoO4 is an especially attractive candidate

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Discussion

Conclusion