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

Abstract

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.

Facile Synthesis of Co3O4/CoMoO4 Heterostructure Nanosheets for Enhanced Acetone Detection

“…41 The unique electronic structure between the heterostructure interfaces has been also demonstrated in hydrogen evolution catalysts. 42 The subsequent chemical reaction between acetone gas molecules and chemisorbed oxygen leads to more electrons being released and recombining with holes, generating chemiresistive responses and contributing to the enhanced sensitivity to acetone gas. We note that, even when compared to state-of-the-art sensors including those based on n-type SMOs or those sensitized with noble metal catalysts, the Co 3 O 4 /CoMoO 4 NSs having numerous p-p heterojunctions exhibited superior sensing response and a record-low LOD of 10 ppb (Table 1).…”

Regulating the Spin State of FeIII Enhances the Magnetic Effect of the Molecular Catalysis Mechanism

“…Catalytic reactions involving triplet-state O 2 molecules have been one of the hottest research topics nowadays. − Aqueous-phase oxygen evolution reaction (OER) is a significant component of the oxygen-involved catalytic reactions. , However, it is hampered by its sluggish kinetics owing to the complex four-electron process, which is typically recognized as the bottleneck for water splitting. − In principle, the formation of the O–O bond requires the destruction of two O–H bonds, involving the spin-electron evolution of the diamagnetic hydroxides to be oxidized into the paramagnetic oxygen molecules. − As a result, the regulation of the spin-state behavior of catalysts would play a considerable role in the OER process. − Although the spin-related OER enhancement has already been observed, it has rarely been systematically and comprehensively demonstrated. Therefore, spintronic electrocatalysis is still a relatively blank field of catalysis.…”

Strain-mediated oxygen evolution reaction on magnetic two-dimensional monolayers

“…29 The heterostructures formed by magnetic 2D materials show good catalytic activity for the OER. [30][31][32] Different from experimental synthesis and exfoliation for achieving magnetic 2D materials, 33,34 a recent theoretical study based on high-throughput computation predicted 56 possible magnetic 2D materials that are held by weak vdW interactions in their bulk states. 35 Magnetic 2D materials possess a flat atomic structure and a high surface-to-volume ratio, making an ideal platform for catalytic reactions.…”