Title
Magnetic FeM (M = Ag, Co, Cu, and Ni) nanocrystals as electrocatalysts for hydrogen evolution reaction
Date Issued
01 June 2022
Access level
metadata only access
Resource Type
journal article
Author(s)
Freire T.M.
Freire R.M.
Franco M.L.
de Oliveira R.C.
Denardin J.C.
Oliveira F.G.S.
Vasconcelos I.F.
Casciano P.N.S.
de Lima-Neto P.
Santos-Oliveira R.
Fechine P.B.A.
Brazilian Center for Research in Physics (CBPF)
Publisher(s)
Elsevier Ltd
Abstract
Iron-based magnetic nanocrystals (FeM@OAm, M = Ag, Co, Cu, and Ni; OAm = oleylamine) electrocatalysts have been successfully synthesized via oleylamine reduction of metal salts method. FeCo is arranged in a body-centered cubic (bcc) unit cell, while FeNi, FeAg, and FeCu are in a face-centered cubic (fcc) structure. All the samples have different morphologies with a diameter average size varying of 6.4 ± 1.0 to 21.7 ± 5.1 nm, depending on the bimetallic composition. The samples have ferrimagnetic behavior with low coercive field and high saturation magnetization values at room temperature. Furthermore, it has been shown that FeAg fits better in the solid solution category. Among heterogeneous electrocatalysts synthesized, FeCo nanocrystals show lower overpotential (−564 mV) in comparison to FeAg (−584 mV), FeNi (−666 mV), and FeCu (−591 mV). The Tafel plots showed that the hydrogen evolution reaction (HER) activity for electrocatalyst following a mixed of Volmer−Heyrovsky reaction mechanism, suggests that reaction Volmer is the determining step. In addition, all electrocatalysts showed stability in tests of continuous operations showing only low potential variation. The EIS study shows system characterized by two time-constant, both of them may related to the kinetics of the HER related to the charge transfer kinetics and the hydrogen adsorption. Thus, these materials are sustainable for electrochemical water splitting since showed acceptable electrocatalytic performance toward HER in alkaline media with excellent physical stability and abundance of active sites for HER.
Volume
18
Language
English
OCDE Knowledge area
Electroquímica
Scopus EID
2-s2.0-85130508196
Source
Materials Today Sustainability
ISSN of the container
25892347
Sponsor(s)
This work was supported by Brazilian agencies: CAPES (Finance Code 001 - PROEX 23038.000509/2020–82 ), CNPq ( 408790/2016-4 ), Funcap ( PNE-0112-00048.01.00/16 ), and Chilean agencies Basal CEDENNA AFB180001 , ANID/CONICYT/Fondecyt 1200782 and 11200425. P. de Lima-Neto thanks CNPq for his grant (304152/2018-8).
Sources of information: Directorio de Producción Científica Scopus