Low-cost high entropy alloy (HEA) for high-efficiency oxygen evolution reaction (OER)

Sharma, L and Katiyar, NK and Parui, A and Das, R and Kumar, R and Tiwary, CS and Singh, AK and Halder, A and Biswas, K (2021) Low-cost high entropy alloy (HEA) for high-efficiency oxygen evolution reaction (OER). In: Nano Research .

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Abstract

Oxygen evolution reaction (OER) is the key step involved both in water splitting devices and rechargeable metal-air batteries, and hence, there is an urgent need for a stable and low-cost material for efficient OER. In the present investigation, Co�Fe�Ga�Ni�Zn (CFGNZ) high entropy alloy (HEA) has been utilized as a low-cost electrocatalyst for OER. Herein, after cyclic voltammetry activation, CFGNZ-nanoparticles (NPs) are covered with oxidized surface and form high entropy (oxy) hydroxides (HEOs), exhibiting a low overpotential of 370 mV to achieve a current density of 10 mA/cm2 with a small Tafel slope of 71 mV/dec. CFGNZ alloy has higher electrochemical stability in comparison to state-of-the art RuO2 electrocatalyst as no degradation has been observed up to 10 h of chronoamperometry. Transmission electron microscopy (TEM) studies after 10 h of long-term chronoamperometry test showed no change in the crystal structure, which confirmed the high stability of CFGNZ. The density functional theory (DFT) based calculations show that the closeness of d(p)-band centers to the Fermi level (EF) plays a major role in determining active sites. This work highlights the tremendous potential of CFGNZ HEA for OER, which is the primary reaction involved in water splitting. Figure not available: see fulltext.. © 2022, Tsinghua University Press and Springer-Verlag GmbH Germany, part of Springer Nature.

Item Type:	Journal Article
Publication:	Nano Research
Publisher:	Tsinghua University
Additional Information:	The copyright for this article belongs to Tsinghua University
Keywords:	Chronoamperometry; Costs; Crystal structure; Cyclic voltammetry; Density functional theory; Design for testability; Electrocatalysts; Entropy; High resolution transmission electron microscopy; High-entropy alloys; Metal-air batteries; Oxygen; Ruthenium compounds, Electrochemical stabilities; High-efficiency; Nanoparticle (NPs); Oxidized surfaces; Oxygen evolution reaction (oer); Primary reaction; State of the art; Water splitting, Oxygen evolution reaction
Department/Centre:	Division of Chemical Sciences > Materials Research Centre
Date Deposited:	03 Dec 2021 08:30
Last Modified:	03 Dec 2021 08:30
URI:	http://eprints.iisc.ac.in/id/eprint/70211

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