Hydrogen adsorption, dissociation and diffusion on two-dimensional Ti2C monolayer. (2nd November 2017)

• Record Type: Journal Article
• Authors: Wang, Shun; Du, Yulei; Liao, Wenhe; Sun, Zhengming
• Is Part Of: International journal of hydrogen energy. Volume 42:Number 44(2017)
• Page Start: 27214
• Page End: 27219
• Publication Date: 2017-11-02
• Subjects: First-principles -- Hydrogen storage properties -- Adsorption -- Diffusion -- Ti2C -- MXene; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2017.09.111
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: The adsorption, dissociation and diffusion of hydrogen on two-dimensional (2D) Ti2 C monolayer with and without carbon vacancies have been investigated by first-principles calculations based on density functional theory. Weak molecular physisorption was observed for the adsorption of H2 on 2D Ti2 C monolayer with end-on configuration. However, for the side-on configuration, the H2 molecule decomposes spontaneously and then the two H atoms prefer to bond to the surface Ti atoms at the monolayer. Based on the chemical bonding analysis, the mechanism of the dissociation of H2 has been elucidated. Moreover, the hydrogen diffusion on the Ti2 C surface with and without carbon vacancies was investigated. A better hydrogen diffusion property was found for the Ti2 C monolayer with carbon vacancies. The energetics for H penetration from surface to the solute site in the bulk was also studied. Highlights: Hydrogen adsorption, dissociation and diffusion on 2D Ti2 C monolayer were studied. H atoms prefer to bond to the surface Ti atoms at Ti2 C monolayer. H2 molecule splits into single atoms on surface of Ti2 C monolayer. The permeation of H in Ti2 C monolayer can be improved by creating carbon vacancies. Hydrogen diffusion can be improved by introducing carbon vacancies into 2D Ti2 C.