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

• Published in: Energy & fuels 2021-05, Vol.35 (9), p.8345-8357
• Main Authors: Mylarapattana Shankaranarayana, Anantha, Dinesh, Anarghya, Siddaramanna, Ashoka, Lakkepally, Shreenivasa, Viswanatha, R, Venkatesh, Krishna, Kumarswamy, Yogesh K, Muralidhara, Handanahally Basavarajaiah
• Format: Article
• Language: English
• Subjects: Batteries and Energy Storage
• ISSN: 0887-0624; 1520-5029
• DOI: 10.1021/acs.energyfuels.1c00378

The stable flower-like layered structure of molybdenum disulfide (MoS2)–graphene oxide (GO) nanocomposites was synthesized by a one-pot hydrothermal process. The novel nanoarchitecture of MoS2–GO nanocomposites acts as an electrocatalyst in multifunctional electrochemical performance. The distribution and morphological studies for MoS2–GO nanocomposites were analyzed via X-ray diffraction, energy-dispersive 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 MoS2–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 MoS2–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 cm2 was found to be 99.95% of coulombic efficiency (ηc), with a corresponding peak power density of 75.60 mW cm–2. Furthermore, in 1.0 M KOH, MoS2–GO nanocomposites demonstrate effective electrocatalysis for the oxygen evolution reaction (OER). The complete catalytic impact of MoS2–GO nanocomposites toward the OER was investigated. The MoS2–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 MoS2–GO nanocomposites was found to be significantly higher than that of the bare screen-printed electrode and MoS2.