Manipulating Spin Exchange Interactions and Spin-Selected Electron Transfers of 2D Metal Phosphorus Trisulfide Crystals for Efficient Oxygen Evolution Reaction

Abstract

Because oxygen molecules in the ground state favor a triplet spin configuration, spin-polarized electrons at electrocatalysts may promote the generation of parallel spin-aligned oxygen atoms, enhancing oxygen evolution reaction (OER) kinetics. In this study, a significant enhancement of OER performance is demonstrated by controlling the spin-exchange interaction and spin-selected electron transfer of 2D CoxFe1−xPS3 (x = 0–0.45) van der Waals (vdW) single crystals through Co doping. The pristine FePS3 exhibits antiferromagnetic orbital ordering, while the Co-doped FePS3 exhibits the emergence of interatomic ferromagnetism due to doping-mediated magnetic exchange interactions. The coupling between Fe and Co ions in the Co-doped FePS3 crystal allows the formation of efficient spin-selective electron transfer channels compared to the pristine FePS3. The correlation of spin-exchange interactions and spin-selected electron transfers of 2D Co-doped FePS3 crystals with a superior OER performance is further revealed by superconducting quantum interference device magnetometer, in situ X-ray absorption near edge spectra and density functional theory simulations. The result suggests that manipulating the spin-exchange interactions of 2D vdW crystals to enhance the spin-selected electron transfer efficiencies through doping is an effective strategy to boost their OER catalytic performances.