Enhanced Hydrogen Storage of a Functional material: Hf2CF2 MXene with Li Decoration

Gencer, Ayşenur
Aydın, Sezgin
Sürücü, Özge
Wang, Xiaotian
Deligöz, Engin
Sürücü, Gökhan
In this paper, the hydrogen storage properties of the Li-decorated stable Hf2CF2MXene layer, obtained by the exfoliation of Al from Hf2AlC and F-termination, are considered by using first-principles calculations based on Density Functional Theory. First, the stability characteristics of the host structure (Hf2CF2layer) are examined by investigating bulk Hf2AlC. To enhance the adsorbed number of H2molecules, the well-defined initial H2coordinates are constructed by CLICH (Cap-Like Initial Conditions for Hydrogens) and Monte Carlo-based algorithms. After the geometry optimizations of the designed H2systems on the Li/Hf2CF2layer, the adsorption energies of nH2/Li/Hf2CF2n=1-10, 15, 20 and 25 systems are calculated, and the suitable values (0.2-0.6 eV/H2) are obtained up to 15H2. For n=20 and 25 systems, which have adsorption energies of 0.15 eV/H2and 0.16 eV/H2, respectively. The structural properties and adsorption geometries of these molecules are analyzed. Additionally, the partial density of the states, electron density difference maps, and Mulliken atomic charges are presented to identify the actual binding mechanism of the systems. The results reveal that the Li-decorated Hf2CF2MXene layer can be preferred for the hydrogen storage applications due to its stable nature and the convenient adsorption characteristics.

Citation Formats
A. Gencer, S. Aydın, Ö. Sürücü, X. Wang, E. Deligöz, and G. Sürücü, “Enhanced Hydrogen Storage of a Functional material: Hf2CF2 MXene with Li Decoration,” Applied Surface Science, pp. 149484–149490, 2021, Accessed: 00, 2021. [Online]. Available: https://www.sciencedirect.com/science/article/pii/S0169433221005602?via%3Dihub.