Modulated interfacial electron transfer of MXene-Tx@CoS for the oxygen evolution reaction

Abstract

Charge accumulation at the interface of multicomponent catalysts remains a challenge to the enhancement of the oxygen evolution reaction (OER). Herein, we reported the modulation of interfacial electron transfer between MXenes with different surface terminal groups (MXene-T_x) and CoS based on theoretical simulations and experimental verification. The surface charge distribution and interfacial electron transfer of MXenes terminated by fluorine, oxygen and hydroxyl can be calculated by the density functional theory calculations. The relationship between electron transfer and theoretical OER overpotential was highlighted as a volcano plot trend as follows: η_MXene@CoS (1.63e) > η_MXene-F@CoS (0.53e) > η_MXene=O@CoS (0.84e) > η_MXene-OH@CoS (1.23e). The optimized interfacial electron transfer of MXene-OH@CoS promoted the adsorption of intermediates, enhancing the intrinsic activity and reducing the energy barrier of the OER. Revealing the relationship between interfacial electron transfer and electrocatalytic properties provided a guidance for electrocatalyst design and synthesis.