Spin Selectivity Induced by the Interface Effect for Boosted Water Oxidation

Creating highly effective electrocatalysts for the oxygen evolution reaction (OER) holds paramount importance in advancing carbon-neutral hydrogen production through water electrolysis. Recent research highlights the crucial role of spin effects on the OER, emphasizing that the manipulation of spin polarization is a promising strategy to augment the OER kinetics. Here, we present a core–shell heterostructure electrocatalyst, which leverages the strong coupling of the interface between antiferromagnetic Co3O4 and NiFe-layered double hydroxide (NiFe-LDH) to trigger a spontaneous magnetic response enhancement, which suggests the strong double exchange interaction at the interface of the core–shell heterostructure. This electrocatalyst displays a 26-fold increase in intrinsic OER activity compared to pristine NiFe-LDH at an overpotential of 0.25 V. Through experimental and computational analyses, we find that the strong double exchange interaction within the heterostructure creates polarized spin conduction channels at the interface, which enables efficient accumulation of electrons with appropriate spin states, thereby lowering the energy barrier for the generation of triplet O2. Our work presents a promising approach to designing high-performance OER catalysts by introducing spin selectivity in traditional metal oxide electrocatalysts.