The Investıgatıon Of Hydrogen Storage On Some Lıght Elements Decorated Two Dımensıonal Carbon Allotropes Usıng Ab-Inıtıo Methods


Thesis Type: Doctorate

Institution Of The Thesis: Gazi Üniversitesi, Fen Bilimleri Enstitüsü, Turkey

Approval Date: 2019

Thesis Language: Turkish

Student: İREM ALP

Supervisor: YASEMİN ÇİFTCİ

Abstract:

The hydrogen storage properties of light metal atom decorated pentaheptite graphene allotropes (Dmetal/ThMoB4-C ve Dmetal/YCrB4-C; Dmetal = Li, Na, Be, Mg, and Ca) are systematically investigated by density functional first-principles calculations within DMol3 package. After well-converged geometry optimizations, the binding energies of adatoms are examined to predict any clustering problem. The single- and double-sided hydrogen storage on Dmetal/ThMoB4-C and Dmetal/YCrB4-C are performed up to 10H2 and 20H2, respectively. The number of hydrogen molecules, the average adsorption energies of which are in the range of 0,2-0,6 eV/H2 and thus provide a convenient physical adsorption-desorption cycle is determined. Afterwards, a detailed examination on the binding mechanism between the constituents of these H2 adsorbed metal decorated systems available is presented by density of states, Mulliken charge analysis, and density difference calculations. The computation yields in high gravimetric densities with suitable and favorable adsorption energies for Dmetal/ThMoB4-C. In this way, it is concluded that the Dmetal/ThMoB4-C structures can especially be considered as promising hydrogen storage media among the systems studied in the thesis.