ChemRxiv
These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
FeNi-complete manuscript.pdf (4.44 MB)

Ferromagnetic–Antiferromagnetic Coupling Core–Shell Nanoparticles with Spin Conservation for Water Oxidation

preprint
submitted on 22.03.2021, 03:05 and posted on 23.03.2021, 09:49 by Jingjie Ge, Riccardo Ruixi Chen, Xiao Ren, Xia Li, Jiawei Liu, Samuel Jun Hoong Ong, Junling Wang, Zhichuan J. Xu

Rational design of active oxygen evolution reaction (OER) catalysts is critical for the overall efficiency of water electrolysis. OER reactants and products’ differing spin states is one of causes to slow OER kinetics. Thus, spin conservation plays a crucial role in enhancing OER performance. In this work, we design ferromagnetic (FM)–antiferromagnetic (AFM) Fe3O4@Ni(OH)2 core–shell catalysts. The interfacial FM–AFM coupling of these catalysts facilitates selective removal of electrons with spin direction opposing the magnetic moment of FM core, improving OER kinetics. The shell thickness is found critical in retaining the coupling effect for OER enhancement. The magnetic domain structure of the FM core also plays a critical role. With a multiple domain core, the applied magnetic field aligns the magnetic domains, optimising the electron transport process. A significant enhancement of OER activity is observed for the multiple domain core catalysts. With a single domain FM core with ordered magnetic dipoles, the spin-selective electron transport with minimal scattering is facilitated even without an applied magnetic field. We therefore draw a magnetism/OER activity model that depends on two main parameters: interfacial spin coupling and domain structure. Our findings provide new design principles for active OER catalysts.

Funding

Ministry of Education Singapore Tier 2 grant (MOE2018-T2-2-027)

History

Email Address of Submitting Author

xuzc@ntu.edu.sg

Institution

Nanyang Technological University

Country

Singapore

ORCID For Submitting Author

0000-0001-7746-5920

Declaration of Conflict of Interest

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Exports

ChemRxiv

Exports