Ni-Xides (B, S, and P) for Alkaline OER : Shedding Light on Reconstruction Processes and Interplay with Incidental Fe Impurities as Synergistic Activity Drivers
El-Refaei, Sayed Mahmoud (Max-Planck-Institut für Chemische Energiekonversion)
Llorens Rauret, David (Institut Català de Nanociència i Nanotecnologia)
Manjón, Alba G. (Institut Català de Nanociència i Nanotecnologia)
Spanos, Ioannis (Max-Planck-Institut für Chemische Energiekonversion)
Zeradjanin, Aleksandar (Max-Planck-Institut für Chemische Energiekonversion)
Dieckhöfer, Stefan (Ruhr University Bochum. Analytical Chemistry)
Arbiol i Cobos, Jordi (Institut Català de Nanociència i Nanotecnologia)
Schuhmann, Wolfgang (Ruhr University Bochum. Analytical Chemistry)
Masa, Justus (Max-Planck-Institut für Chemische Energiekonversion)

Date:	2024
Abstract:	Ni-Xides (X = B, P, or S) exhibit intriguing properties that have endeared them for electrocatalytic water splitting. However, the role of B, P, and S, among others, in tailoring the catalytic performance of the Ni-Xides remains vaguely understood, especially if they are studied in unpurified KOH (Un-KOH) because of the renowned impact of incidental Fe impurities. Therefore, decoupling the effect induced by Fe impurities from inherent material reconstruction processes necessitates investigation of the materials in purified KOH solutions (P-KOH). Herein, studies of the OER on NiB, NiP, and NiS in P-KOH and Un-KOH coupled with in situ Raman spectroscopy, ex situ post-electrocatalysis, and online dissolution studies by ICP-OES are used to unveil the distinctive role of Ni-Xide reconstruction and the role of Fe impurities and their interplay on the electrocatalytic behavior of the three Ni-Xide precatalysts during the OER. There was essentially no difference in the OER activity and the electrochemical Ni/Ni redox activation fingerprints of the three precatalysts via cyclic voltammetry in P-KOH, whereas their OER activity was considerably higher in Un-KOH with marked differences in the intrinsic activity and evolution of the Ni/Ni fingerprint redox peaks. Thus, in the absence of Fe in the electrolyte (P-KOH), neither the nature of the guest element (B, P, and S) nor the underlying reconstruction processes are decisive activity drivers. This underscores the crucial role played by incidental Fe impurities on the OER activity of Ni-Xide precatalysts, which until now has been overlooked. In situ Raman spectroscopy revealed that the nickel hydroxide derived from NiB exhibits higher disorder than in the case of NiP and NiS, both exhibiting a similar degree of disorder. The guest elements thus influence the degree of disorder of the formed nickel oxyhydroxides, which through their synergistic interaction with incidental Fe impurities concertedly realize high OER performance.
Grants:	Agencia Estatal de Investigación PID2020-116093RB-C43 Agencia Estatal de Investigación RYC2021-033479-I European Commission CEX2021-001214-S Agència de Gestió d'Ajuts Universitaris i de Recerca 2021/SGR-00457
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Oxygen Evolution Reaction ; Reconstruction ; Nickel Hydroxide ; Nickel Phosphide ; Nickel Sulfide ; Nickel Boride
Published in:	ACS Applied Energy Materials, Vol. 7, Issue 4 (February 2024) , p. 1369-1381, ISSN 2574-0962

DOI: 10.1021/acsaem.3c03114
PMID: 38425378

13 p, 7.4 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Catalan Institute of Nanoscience and Nanotechnology (ICN2)
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Articles > Published articles