Switchable Spin Transport at Chiral-Ferrimagnetic Nanointerfaces for Selective Oxygen Evolution

Abstract Spin-dependent charge transfer offers a promising strategy to control multielectron electrocatalysis, yet the mechanistic coupling between molecular spin filtering and magnetic polarization at catalytic interfaces remains poorly understood. Here, we develop a chiral supramolecular–ferrimagnetic heterointerface by combining a chiral naphthalene diimide (NDI) supramolecular layer with Co0.6Ni0.4Fe2O4 and explore its role in oxygen evolution reaction (OER) catalysis. To disentangle the coupled response of the molecular chirality and the magnetic-field polarization, a four-condition experimental matrix was employed. The chiral–ferrimagnetic interface shows a pronounced catalytic response to the magnetic field, and an increase in the magnetoresistance, and a more significant decrease in the interfacial charge-transfer resistance as revealed by distribution-of-relaxation-times (DRT) analysis. Quantitative assessment of the different conditions further enables evaluation of the non-additive interaction between molecular chirality and magnetic polarization. Spin-trapping electron paramagnetic resonance (EPR) measurements reveal that the steady-state population of detectable oxygen-derived radical species is lower with the chiral catalyst, and H2O2 quantification shows strongly suppressed peroxide formation, indicating altered OER pathway selectivity. The transport, kinetic, and reaction-pathway measurements collectively establish a mechanistic link between spin-dependent interfacial charge transfer and OER catalysis. These results demonstrate that the coupling of molecular chirality and ferrimagnetic polarization provides a strategy for cooperative regulation of interfacial electron transfer kinetics and oxygen evolution pathway selectivity and highlights chiral–magnetic interfaces as a platform for spin-controlled electrocatalysis.