Computational design of a switchable heterostructure electrocatalyst based on a two-dimensional ferroelectric In2Se3 material for the hydrogen evolution reaction

摘要

A theoretical design for an ON-OFF switchable HER catalyst using the two-dimensional ferroelectric (2D-FE) III2VI3 compound In2Se3 is reported in this paper. With vertical stacking of the basal plane of In2Se3 on top of the transition metal cobalt, a set of ab initio calculations reveals that the reversible polarization switching of In2Se3 can turn the HER activity of the heterostructure ON and OFF. The principle of HER activation/deactivation of the heterostructure is discussed in terms of the electronic structures, and the polarization-dependent modulation of electronic energy and charge transfer between In2Se3 and the transition metal are identified as the key factors. The distinct electron transfer mechanisms for the structures based on mono- and bilayers of In2Se3 are identified in terms of the different electronic connections between Co and In2Se3, and the structures are labelled as "direct" and "indirect" catalysts, respectively. This work provides insight into a possible pathway for designing dynamically controlled electrocatalysts based on 2D materials without introducing any chemical disorder.