Ferroelectric polarization-controlled hydrogen storage in heteroatom-functionalized graphene/In₂Se₃ heterostructures

Area of Science:

• Materials Science
• Energy Storage
• Computational Chemistry

Background:

• Hydrogen storage is crucial for clean energy technologies but faces challenges in material capacity and reversibility.
• Single-atom active sites and ferroelectric materials offer potential for advanced hydrogen storage solutions.

Purpose of the Study:

• To investigate heteroatom-decorated single-vacancy graphene (SVG) and ferroelectric (FE) In2Se3 heterostructures (HSs) for hydrogen storage.
• To explore the role of ferroelectric polarization in tuning hydrogen adsorption and desorption.

Main Methods:

• Density functional theory (DFT) calculations were employed to model and analyze the electronic and structural properties of the heterostructures.
• Investigated the interaction between hydrogen molecules and the Ca-SVG/In2Se3 heterostructures under different polarization states.

Main Results:

• Ca-SVG/In2Se3 heterostructures demonstrated favorable hydrogen storage behavior, accommodating up to seven H2 molecules.
• Downward ferroelectric polarization enhanced Kubas-type interactions for strong adsorption (0.2-0.6 eV).
• Upward polarization weakened interactions, facilitating facile H2 release, and enabling electric-field-controlled desorption.

Conclusions:

• Ferroelectric heterostructures provide a tunable platform for hydrogen storage with polarization-controlled adsorption and release.
• The electronegativity-to-radius ratio (χ/r) is identified as a predictive descriptor for material selection.
• These findings offer insights for designing next-generation hydrogen storage materials.