Electronic modulation of zinc selenide toward efficient alkaline hydrogen evolution

Abstract

Effective electronic modulation is the key to fulfilling the Pt-like hydrogen evolution reaction (HER) activity on selenide-based electrocatalysts, but it also brings a huge challenge to rational structural design. Zinc selenide (ZnSe) is a potential candidate for alkaline HER. However, much fewer endeavours have been dedicated to ZnSe, hence inherent activities still need to be enhanced via facilitating the Volmer and Heyrovsky steps. Herein, we developed a simple fabrication method for copper-doped ZnSe nanoparticles embedded in nitrogen-doped carbon (namely Cu-ZnSe@NC) from bimetallic ZnCu-ZIF to promote alkaline HER. Benefitting from three-dimensional porous morphology and modulated electronic structure, the Cu-ZnSe@NC displays superior HER performance with small overpotential of 84 mV at the current density of 10 mA cm−2, comparable to that of commercial Pt/C. Experimental and theoretical results demonstrate that the incorporation of heteroatom-Cu can not only increase the number of active sites and improve the intrinsic activity of each catalytic site, but also modulate the electronic structure of the catalyst, which is advantageous to boosting H2O adsorption and optimizing the energy barrier for H adsorption for initiating the electrocatalytic pathway at alkaline electrolyte. This work provides a novel understanding for designing of selenide-based composite for HER with improved catalytic activity.