DOD-Graphene: A Promising sp²-Carbon Monolayer for Hydrogen Storage

Area of Science:

• Materials Science
• Computational Chemistry
• Energy Storage

Background:

• Developing efficient solid-state hydrogen storage materials is crucial for clean energy technologies.
• Two-dimensional (2D) materials offer unique properties for gas adsorption and storage.

Purpose of the Study:

• To investigate the potential of a novel 2D carbon allotrope, Dewar-Octa-Decagraphene (DOD-graphene), for solid-state hydrogen storage.
• To evaluate the performance of lithium-functionalized DOD-graphene as a hydrogen carrier.

Main Methods:

• First-principles calculations to study the electronic and structural properties of DOD-graphene.
• Ab initio molecular dynamics (AIMD) simulations to assess stability at 300 K.
• Calculations of lithium adsorption energies and hydrogen storage capacity.
• Thermodynamic isotherm predictions and AIMD simulations for hydrogen desorption.

Main Results:

• Pristine DOD-graphene is a dynamically stable, metallic 2D material.
• Lithium atoms bind strongly to DOD-graphene pores, facilitating hydrogen adsorption.
• Li-decorated DOD-graphene achieves a high gravimetric capacity (7.52 wt %) with optimal binding energies for reversible storage.
• AIMD simulations confirm structural integrity and rapid H2 desorption at 300 K.

Conclusions:

• Li-functionalized DOD-graphene is a promising candidate for next-generation hydrogen storage media.
• The material exhibits robust lithium anchoring, high capacity, and facile, physisorptive hydrogen release.
• Van der Waals interactions mediated by Li+ centers are key to the hydrogen storage mechanism.