Potential hydrogen storage materials from metal decorated 2D-C₂N: an ab initio study

Area of Science:

• Materials Science
• Chemistry
• Physics

Background:

• Two-dimensional nitrogenated holey graphene (2D-C2N) is a promising material for hydrogen storage due to its low density and high surface area.
• However, pristine 2D-C2N exhibits weak interactions with H2, limiting its storage capacity.

Purpose of the Study:

• To investigate the hydrogen storage properties of metal-decorated 2D-C2N using density functional theory.
• To identify optimal metal decorations for enhancing H2 adsorption and storage capacity.

Main Methods:

• Density functional theory (DFT) calculations were employed to study metal (Mg, Ca, Ti, V, Mn, Fe, Co, Ni, Cu, Zn) decorated 2D-C2N.
• Analysis included binding energies, electronic structures, and chemical bonding characteristics.

Main Results:

• Metal decoration on 2D-C2N showed strong binding, preventing metal clustering.
• Magnesium (Mg) decorated 2D-C2N achieved 6.79 wt% hydrogen storage capacity with optimal adsorption energy.
• Mg decoration induced a semiconductor-to-metallic transition and iono-covalent bonding, facilitating H2 adsorption via polarization.

Conclusions:

• Mg decorated 2D-C2N is a highly promising material for efficient hydrogen storage applications.
• The study highlights the potential of tailored material design to overcome limitations in hydrogen storage.