One-Pot Synthesis of Novel Molybdenum Disulfide–Graphene Oxide Nanoarchitecture: An Impeccable Bifunctional Electrode for the Electrochemical Performance of Iron Redox Flow Batteries and Oxygen Evolution Reaction

Abstract

The stable flower-like layered structure of molybdenum disulfide (MoS 2 )−graphene oxide (GO) nanocomposites was synthesized by a one-pot hydrothermal process. The novel nanoarchitecture of MoS 2 −GO nanocomposites acts as an electrocatalyst in multifunctional electrochemical performance. The distribution and morphological studies for MoS 2 −GO nanocomposites were analyzed via X-ray diffraction, energydispersive X-ray analysis, scanning electron microscopy, Brunauer−Emmett−Teller, and X-ray photoelectron spectroscopy analysis. Modified graphite felt (MGF) electrodes were developed using a spray-coating process to uniformly distribute MoS 2 −GO nanocomposites on graphite felt. The 1 mg cm −2 MGF electrode showed the best electrochemical activity and electrochemical reversibility toward the redox couples of the iron(II) electrolyte, as indicated in electrochemical impedance spectroscopy, cyclic voltammetry, and Tafel plots; this may be due to the presence of sulfur and oxygen heteroatom layers of the MoS 2 −GO nanocomposites, which are more actively participated in the charge transfer redox reactions of the iron(II) electrolyte. Iron redox flow battery performance with an active area of 132 cm 2 was found to be 99.95% of coulombic efficiency (η c ), with a corresponding peak power density of 75.60 mW cm −2 . Furthermore, in 1.0 M KOH, MoS 2 −GO nanocomposites demonstrate effective electrocatalysis for the oxygen evolution reaction (OER). The complete catalytic impact of MoS 2 −GO nanocomposites toward the OER was investigated. The MoS 2 −GO nanocomposites show an overpotential of 1.49 V (recorded at η of 10) and a Tafel slope of 381 mV dec −1 and remain stable after 20 h of chronoamperometry in 1.0 M KOH. The OER activity of MoS 2 −GO nanocomposites was found to be significantly higher than that of the bare screen-printed electrode and MoS 2 .

Synergetic Functionalization of the ZnS@ASCs Biocomposite: For Enhanced Electrochemical Performance of Redox Flow Batteries and Supercapacitors

“…IRFBs are considered one of the interesting, revolutionary energy storage technologies that use earth-abundant, eco-friendly, and economical iron and water as the electrolyte. 13,21,28 The carbon-based electrodes are majorly used in IRFBs because of their high electrical conductivity, stability, and reversibility. 29,30 IRFBs are acknowledged as being more effective and preferable for grid-level storage.…”

Synthesis of Cauliflower-like Reduced Graphene Oxide Nickel Sulfide Nanocomposites for the Vanadium Redox Battery and Supercapacitor Application

“…30−33 In a number of published articles, carbon-based materials like GO and reduced graphene oxide (RGO) show promising outcomes in the domain of energy storage and conversion. 34,35 In case of the RGO-metal sulfide composites, RGO exhibits a large and stable surface area for the mobility of free electrons in metal sulfides to facilitate the electrochemical reaction. 36−38 Among other metal sulfides, nickel sulfides have attracted researchers owing to their abundance, low-cost, eco-friendliness, and high theoretical capacity.…”

“…Metal sulfides have recently gathered a lot of interest as prospective materials for the preparation of electrode due to their low cost, high abundance of electron conductivity, cheap cost, and being environmentally friendly. − In a number of published articles, carbon-based materials like GO and reduced graphene oxide (RGO) show promising outcomes in the domain of energy storage and conversion. , In case of the RGO-metal sulfide composites, RGO exhibits a large and stable surface area for the mobility of free electrons in metal sulfides to facilitate the electrochemical reaction. − …”