Magnetic Field-Assisted Oxygen Evolution Reaction by the Spin Polarization in Medium-Entropy Selenides

In recent years, the magnetic field utilization has emerged as an effective approach to enhance the oxygen evolution reaction (OER) performance of catalysts through the magneto-thermal effect, magneto-hydrodynamic effect, and spin-polarization effect. The OER process can be influenced by controlling the spin state of intermediates in the spin-polarization effect. Moreover, selenides with abundant d-electrons, high polarizabilities, and metallicity properties render them highly suitable for the application in OER. Medium-entropy compounds exhibit characteristics of outstanding catalytic activity, structural stability, cocktail effect, etc. Herein, due to the intrinsic correlation between the magnetic enhancement effect and spin-dependent dynamics, the medium-entropy selenide FeCoNiVSe x nanosheet array catalyst exhibits a 317 mV overpotential and 40 h stability at 100 mA cm –2 current density in the presence of a 75 mT magnetic field. The spin-popularization effect, whereby the magnetic field instigates a conversion of spin states between the radical singlet and triplet states, can optimize the reaction pathway, enhance the reaction efficiency, and exhibit the persistent magnetic enhancement of FeCoNiVSe x . This work provides valuable insights into the mechanism of understanding of magnetic field-assisted OER processes.