Electronic structure modulation via selenium-induced homologous CoSe2-MnSe heterointerface for stability-activity optimization of electrochemical water splitting

Abstract

The design of catalysts is restricted by the trade-off between activity and stability, making it impossible to achieve a high-performance electrocatalytic water splitting process. Thus, this work proposes an electronic structure modulation strategy induced by homologous CoSe 2 -MnSe heterointerface (CoMnSe) to construct the highly stable-active electrocatalyst grown on nickel foam (NF) with the ordered nanowire array architecture (N-CQDs/CoMnSe/NF). The Se element leads to the charge redistribution and strong coupling effect in homologous heterointerface, which are conducive to optimize reaction kinetics and enhance structure stability of materials. Moreover, the N-CQDs served as a transfer bridge for electrons, reduce the charge transport barrier for full system, providing the excellent HER/OER performance. Beyond boosting the reaction kinetics, the synergy between N-CQDs and CoMnSe effectively prevents aggregation of the layered framework, leading to enhanced long-term cycling stability. Therefore, the N-CQDs/CoMnSe/NF possesses the long-term stability (96 h) and low overpotentials (73 mV for HER, 265 mV for OER), along with a minimal overall water-splitting cell voltage of 1.56 V, highlighting its great potential for high-efficiency water electrolysis.