Field-Free Improvement of Oxygen Evolution Reaction in Magnetic Two-Dimensional Heterostructures

Ferromagnetic (FM) electrocatalysts have been demonstrated to reduce the kinetic barrier of oxygen evolution reaction (OER) by spin-dependent kinetics and thus enhance the efficiency fundamentally. Accordingly, FM two-dimensional (2D) materials with unique physicochemical properties are expected to be promising oxygen-evolution catalysts; however, related research is yet to be reported due to their air-instabilities and low Curie temperatures (T_C). Here, based on the synthesis of 2D air-stable FM Cr₂Te₃ nanosheets with a low T_C around 200 K, room-temperature ferromagnetism is achieved in Cr₂Te₃ by proximity to an antiferromagnetic (AFM) CrOOH, demonstrating the accomplishment of long-ranged FM ordering in Cr₂Te₃ because the magnetic proximity effect stems from paramagnetic (PM)/AFM heterostructure. Therefore, the OER performance can be permanently promoted (without applied magnetic field due to nonvolatile nature of spin) after magnetization. This work demonstrates that a representative PM/AFM 2D heterostructure, Cr₂Te₃/CrOOH, is expected to be a high-efficient magnetic heterostructure catalysts for oxygen-evolution.