Multi-domain versus single-domain: a magnetic field is not a must for promoting spin-polarized water oxidation

• Main Authors: Ge, Jingjie, Ren, Xiao, Chen, Riccardo Ruixi, Sun, Yuanmiao, Wu, Tianze, Ong, Samuel Jun Hoong, Xu, Jason Zhichuan
• Other Authors: School of Materials Science and Engineering
• Format: Article
• Language: English
• Published: 2023
• Subjects: Engineering::Materials; Ferromagnetic Catalyst; Magnetic Domain
• Online Access: https://hdl.handle.net/10356/169299
• Institution: Nanyang Technological University

The reaction kinetics of spin-polarized oxygen evolution reaction (OER) can be enhanced by ferromagnetic (FM) catalysts under an external magnetic field. However, applying a magnetic field necessitates additional energy consumption and creates design difficulties for OER. Herein, we demonstrate that a single-domain FM catalyst without external magnetic fields exhibits a similar OER increment to its magnetized multi-domain one. The evidence is given by comparing the pH-dependent increment of OER on multi- and single-domain FM catalysts with or without a magnetic field. The intrinsic activity of a single-domain catalyst is higher than that of a multi-domain counterpart. The latter can be promoted to approach the former by the magnetization effect. Reducing the FM catalyst size into the single-domain region, the spin-polarized OER performance can be achieved without a magnetic field, illustrating an external magnetic field is not a requirement to reap the benefits of magnetic catalysts.