1T-MoS2 Coordinated Bimetal Atoms as Active Centers to Facilitate Hydrogen Generation.

Qiong Peng,Xiaosi Qi,Yanli Chen,Xiu Gong

doi:10.3390/ma14154073

Abstract

Anchoring single metal atoms has been demonstrated as an effective strategy to boost the catalytic performance of non-noble metal 1T-MoS2 towards hydrogen evolution reaction (HER). However, the dual active sites on 1T-MoS2 still remain a great challenge. Here, first-principles calculations were performed to systematically investigate the electrocatalytic HER activity of single and dual transition metal (TM) atoms bound to the 1T-MoS2 monolayer (TM@1T-MoS2). The resulted Ti@1T-MoS2 exhibits excellent structural stability, near-thermoneutral adsorption of H* and ultralow reaction barrier (0.15 eV). It is a promising single metal atom catalyst for HER, outperformed the reported Co, Ni and Pd anchoring species. Surprisingly, by further introducing Pd atoms coordinated with S atoms or S vacancies on the Ti@1T-MoS2 surface, the resulted catalyst not only maintains the high HER activity of Ti sites, but also achieves new dual active moiety due to the appropriate H* adsorption free energy on Pd sites. This work is of great significance for realizing dual active centers on 1T-MoS2 nanosheets and offers new thought for developing high-performance electrocatalysts for HER.

Highlights

The electrocatalytic hydrogen evolution reaction (HER: 2H+ + 2e− → H2 ) is the key to achieve clean hydrogen energy [1,2]
Firstprinciples calculations and automatic frameworks of material screening methods were employed to reveal the electrocatalytic HER activity of 3d, 4d, 5d transition metal (TM) single and dual atoms bound to the 1T-MoS2 monolayer
The structure and catalytic performance of mono/bimetal atoms mediated 1T-MoS2 were investigated through first-principles calculations based on the spin-polarized density functional theory (DFT) [26] and automatic frameworks of material screening methods

Summary

Introduction

The electrocatalytic hydrogen evolution reaction (HER: 2H+ + 2e− → H2 ) is the key to achieve clean hydrogen energy [1,2]. Considering that the HER kinetics under acidic conditions is much faster than that in alkaline solution, it is highly desirable and urgent to mining high activity, low cost, stable electrocatalysts for HER in acidic media [5]. Transition metal embedded heteroatom-doped carbon nanosheets [6], two-dimensional (2D) transition metal sulfides [7,8], borides [9], oxides [10], phosphides [11] etc., have been reported as promising candidates to replace precious Pt for HER These catalysts are still far from being commercialized because of their poor conductivity or insufficient hydrophilicity

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