Reactant friendly hydrogen evolution interface based on di-anionic MoS2 surface

Zhaoyan Luo,Yuqi Yang,Xian Wang,Wei Xing,Junjie Ge,Yang Li,Hao Zhang,Zhao Jin,Changpeng Liu,Zheng Jiang

doi:10.1038/s41467-020-14980-z

Abstract

Engineering the reaction interface to preferentially attract reactants to inner Helmholtz plane is highly desirable for kinetic advancement of most electro-catalysis processes, including hydrogen evolution reaction (HER). This, however, has rarely been achieved due to the inherent complexity for precise surface manipulation down to molecule level. Here, we build a MoS2 di-anionic surface with controlled molecular substitution of S sites by –OH. We confirm the –OH group endows the interface with reactant dragging functionality, through forming strong non-covalent hydrogen bonding to the reactants (hydronium ions or water). The well-conditioned surface, in conjunction with activated sulfur atoms (by heteroatom metal doping) as active sites, giving rise to up-to-date the lowest over potential and highest intrinsic activity among all the MoS2 based catalysts. The di-anion surface created in this study, with atomic mixing of active sites and reactant dragging functionalities, represents a effective di-functional interface for boosted kinetic performance.

Highlights

Engineering the reaction interface to preferentially attract reactants to inner Helmholtz plane is highly desirable for kinetic advancement of most electro-catalysis processes, including hydrogen evolution reaction (HER)
Hydrogen evolution reaction (HER) electrocatalysts that are fast in kinetics, low in energy consumption, and cost-effective in nature were intensively searched, among which MoS2 has emerged as a promising candidate[1,2,3]
The density functional theory (DFT) calculations reveal that the Ru-S bond energy (0.92 eV) is 0.87 eV lower than the Mo-S bond (1.79 eV), is more prone to form adjacent sulfur vacancies (Supplementary Fig. 1)

Summary

Introduction

Engineering the reaction interface to preferentially attract reactants to inner Helmholtz plane is highly desirable for kinetic advancement of most electro-catalysis processes, including hydrogen evolution reaction (HER). The overall kinetic performance (in Volmer-Heyrovsky mechanism) of the MoS2 electrode at fixed potential (E) is shown in Eq 14,5 and is apparently governed by: first, the energetic interaction between atomic hydrogen and the surface site (ΔGH*); second, the reactant (hydronium ions in acid and water in alkaline medium) concentration.

Results

Conclusion