Calcium-atom-modified boron phosphide (BP) biphenylene as an efficient hydrogen storage material

Area of Science:

• Materials Science
• Energy Storage
• Computational Chemistry

Background:

• Porous nanosheets offer large surface areas for energy storage applications.
• Previous research identified Li/Na-metalized BP-biphenylene (b-B3P3) and graphenylene (g-B6P6) for hydrogen storage.
• Alkaline earth metals (AEMs) are explored for enhancing material functionalities.

Purpose of the Study:

• To evaluate hydrogen storage performance of AEM-decorated b-B3P3 and g-B6P6 structures.
• To investigate the stability and hydrogen adsorption capacity of these decorated nanosheets.
• To assess their potential for meeting future hydrogen storage targets.

Main Methods:

• First-principles density functional theory (DFT) calculations were employed.
• Stability of Be, Mg, and Ca decorated b-B3P3 and g-B6P6 sheets was analyzed.
• Hydrogen adsorption energies and gravimetric uptake were calculated.

Main Results:

• Individual Be and Mg atoms showed poor stability, forming aggregates.
• Calcium (Ca) decoration on b-B3P3 and g-B6P6 resulted in stable structures (b-B3P3(mCa) and g-B6P6(nCa)).
• b-B3P3(8Ca) and g-B6P6(16Ca) structures adsorbed 32H2 and 48H2 molecules, respectively.
• Gravimetric H2 uptakes of 7.28 wt% and 5.56 wt% were achieved, surpassing the DOE 2025 target of 5.50 wt%.

Conclusions:

• Ca-decorated b-B3P3 and g-B6P6 nanosheets are promising candidates for efficient hydrogen storage.
• The study highlights the potential of these materials for next-generation energy storage solutions.
• Optimized decoration and structure are crucial for maximizing hydrogen storage capacity.