A DFT study for hydrogen storage application on pristine magnesium dicarbide (MgC₂) monolayer

Area of Science:

• Materials Science
• Computational Chemistry
• Energy Storage

Background:

• Developing efficient hydrogen storage materials is crucial for advancing clean energy technologies.
• Magnesium-based compounds are explored for their potential in hydrogen storage applications.

Purpose of the Study:

• To investigate the hydrogen storage potential of pure magnesium carbide (MgC2) using computational methods.
• To assess the stability, electronic properties, and hydrogen adsorption characteristics of MgC2.

Main Methods:

• Density Functional Theory (DFT) calculations.
• Phonon dispersion and ab initio molecular dynamics (AIMD) simulations.
• Electronic structure and Hirshfeld charge analyses.

Main Results:

• MgC2 exhibits dynamic and structural stability, confirmed by phonon dispersion and AIMD.
• Pure MgC2 is a semiconductor (0.25 eV band gap), becoming metallic upon hydrogen adsorption.
• Physisorption of hydrogen on MgC2 shows moderate binding energy (0.286 eV) and a storage capacity of 2.05%.
• AIMD simulations at 400 K indicate no significant framework distortion upon hydrogen adsorption.

Conclusions:

• MgC2 is a dynamically stable and structurally sound material for hydrogen storage.
• The reversible physisorption mechanism and moderate binding energy make MgC2 suitable for practical hydrogen storage.
• MgC2 presents a viable pathway for developing next-generation clean energy technologies.