Computational Evaluation of Lithium-Functionalized Carbon Nitride (g-C6N8) Monolayer as an Efficient Hydrogen Storage Material

作者：Hussain Tanveer^*; Hankel Marlies; Searles Debra J

来源：Journal of Physical Chemistry C, 2016, 120(44): 25180-25188.

DOI：10.1021/acs.jpcc.6b06182

Quantum chemical density functional theory calculations have been used to study the structural, electronic, and hydrogen storage properties of a monolayer that is a stable allotrope of carbon nitride (g-C6N8). It was observed that a 2 x 2 supercell can bind three, six, and eight lithium (Li) adatoms in different configurations with a binding energy much higher than the cohesive energy of Li, indicating that a distribution of Li over the monolayer can form without clustering of Li occurring. Density of states calculations suggests that adding Li atoms transforms the semiconducting (g-C6N8) monolayer into a conducting one. A significant amount of charge is transferred from Li to the monolayer that induces a partial positive charge on each Li adatom. This facilitates the polarization of the H-2 molecules exposed to Li, which are then held by it through electrostatic and van der Waals interactions. Each Li can adsorb multiple H-2 molecules with adsorption energies that lie within the desired range for an efficient and reversible H2 storage material with a storage capacity of 7.55 wt %.

• 出版日期2016-11-10