A Versatile C/Fe₃O₄/C Self-Heating Electrode for Universal Application of Alternating Magnetic Fields in Electrocatalytic Hydrogen Production

The high-frequency alternating magnetic field (AMF) is considered as a fascinating heating treatment that provides a noninvasive solution to enhance the catalytic efficiency of electrocatalyst. However, practical applications of AMF in electrochemistry are primarily concentrated on magnetic mediums. To broaden its application into nonmagnetic catalysts, herein, a practicable method is reported by modifying the working electrode substrate with magnetic Fe₃O₄ nanoparticles (NPs), which serves as both substrate and self-heating medium by virtue of its rapid and efficient magnetic heating effect associated with Néel relaxation triggered by external high-frequency AMF, thus boosting the catalyst performance upon it. To verify it, Pt NPs and Pt single atoms (SAs), as two representative non-magnetic catalyst, are selected for trials. The results, reveal that, when AMF is applied, Pt NPs@C/Fe₃O₄/C and Pt SAs@C/Fe₃O₄/C display remarkable enhancement of hydrogen evolution reaction magnetocurrent density respectively by ≈ 146% and ≈185%, whereas on unmodified bare glassy carbon there both show unnoticeable change in catalytic performance. The developed strategy opens up a vast space for exploiting the energy of a weak, non-invasive magnetic field.