Biaxial Strain Induced Reversible Hydrogen Storage in 2D Boron Phosphide Biphenylene Material

Abstract

The storage of hydrogen energy is the primary obstacle to its widespread use, underscoring the need for efficient storage materials. Motivated by the increasing prevalence of inorganic biphenylene substitutes, strain-induced modulation of hydrogen storage in 2D boron phosphide biphenylene (BPB) via first-principles calculations is investigated. Pristine BPB is an inefficient substrate for hydrogen storage since the adsorption energy is –0.17 eV/H2, which falls below the DOE requirement. Thus to further enhance the hydrogen adsorption performance, the effect of the strain on BPB monolayer is studied. Compressive strain enhances bond electronic density, strengthening H2 adsorption and increasing adsorption energy. On the application of 1.25% biaxial strain, BPB is able to adsorb 24 H2 molecules, corresponding to 8.8 wt % storage with an adsorption energy of –0.25 eV/H2. The occupation number analysis provides an understanding of the hydrogen uptake behavior within the strained BPB complex across different temperatures and pressures. The work emphasizes strained BPB as a versatile reversible hydrogen storage 2D material.