Alternating magnetic fields enhanced non-magnetic confined-ruthenium nanoparticles for efficient oxygen evolution reaction

Magnetic heating by alternating magnetic field (AMF) is a fascinating solution to break the bottleneck in oxygen evolution reaction (OER) catalyst improvement. However, practical applications of AMF in electrochemistry are always impeded by the inherent characteristics of the catalyst (i.e., non-magnetic nature and oxidizable feature). Here, a self-heating working electrode substrate of C/Fe3O4/C is proposed to be fabricated, on which non-magnetic Ru nanoparticles confined within the amorphous carbon matrix are deposited as the catalytic layer. Under AMF, magnetic Fe3O4 particle can be stimulated and generate the magnetic heating associated with Néel relaxation, which improves the OER efficiency of Ru nanoparticles with the overpotential at 10 mA cm−2 reduced by 72 mV. Together with the high stability rendered by confined structure, the exploitation of AMF on non-magnetic catalyst is confirmed, and the developed strategy offers a general pathway to advance OER catalyst performance in the future.