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Electrochemical Hydrogen Evolution at the Interface of Monolayer VS₂ and Water from First-Principles Calculations

Author:
He, Qiaoqiao, Chen, Xiaobo, Chen, Shiqi, Liu, Lu, Zhou, Fangwang, Li, Xi-Bo, Wang, Guangjin
Source:
ACS applied materials & interfaces 2018 v.11 no.3 pp. 2944-2949
ISSN:
1944-8252
Subject:
aqueous solutions, catalysts, density functional theory, electrochemistry, hydrogen, hydrogen production, phase transition
Abstract:
Density functional theory calculations are carried out to study the hydrogen evolution reaction (HER) at the electrochemical double-layer interface of monolayer 2H phase VS₂ and water. Under typical conditions of HER, the catalyst surface is predicted to have a low hydrogen coverage of about 12%, whereas the aqueous solution side features a high hydronium concentration of about 8.3%. As a result, the HER takes place through the Volmer–Heyrovsky route, with an overall reaction barrier of about 1.0 eV, much larger than that of 1T phase VS₂. This result demonstrates that 2H phase VS₂ is much less reactive than its 1T phase counterpart, and the 1T-to-2H phase transformation induced by thickness reduction may deteriorate the HER activity of VS₂.
Agid:
6270408