An Insight into the Relation of Spin-Polarization and Oxygen Evolution Enhancement with a Monolayer Chiral Covalent Organic Framework Model Catalyst
Zhiping Liu, Shaofang Zhang, Enbing Zhang, Kuo Wei, Miao Zhang, Xiaojuan Li, Dejuan Fa, Steven De Feyter, Guangyuan Feng, Shengbin Lei, Wenping Hu
Abstract
Manipulating the electron spin state through the chiral-induced spin selectivity (CISS) effect provides a novel strategy for enhancing the activity and selectivity of the oxygen evolution reaction (OER). However, developing a quantitative relationship between the CISS effect and the chirality-enhanced OER performance is difficult due to complex influencing factors. Herein, using a ligand exchange strategy, we developed a monolayer chiral covalent organic framework (mc-COF) model catalytic system with adjustable spin polarization (P = ∼49–72%), which allows the decoupling of the CISS effect from other influencing factors on the OER performance. A supralinear dependence between the spin polarization and chirality-enhanced OER performance is established. This confirms that the chirality-enhanced electrocatalytic performance is significantly amplified by spin polarization due to the CISS effect. Moreover, in situ measurements reveal that the CISS effect of mc-COFs optimizes the reaction pathway by aligning *OH spins parallel, suppressing H 2 O 2 formation, facilitating spin-oriented intermediates (*OOH and *OO) at lower potentials, and accelerating *OOH-to-*O–O conversion.