The effect of the electric field intensity on the hydrogen storage of B/N-co-doped graphdiyne nanosheet

Abstract

The importance of substituting fossil fuels with clean and renewable energies, and the introduction of hydrogen as a promising option in this field is one of the most popular challenges for researchers. Here, we performed the spin-polarized DFT calculations to investigate the ability of the hydrogen adsorption and storage of modified graphdiyne (GDY) by B and N atoms (BN-GDY) under positive and negative external electric fields. Our findings show that the BN-GDY nanosheet has a weak interaction with the H2 molecule in absence of the electric field, and the electric field can effectively improve this interaction and increase the adsorption energy of the H2 molecule on the BN-GDY nanosheet. Also, the negative electric field has more effect relative to the positive one, and with increasing the intensity of the electric field, the adsorption energy has an upward trend. At the highest intensities of positive and negative applied fields (±0.046 V/Å), the BN-GDY nanosheet can store up to 4 and 8H2 molecules with the average adsorption energies of −0.253 and −0.258 eV/H2, and the H2 storage capacity can reach up to 3.59 and 6.93 wt%, respectively. The preference of our work for practical application is the free metal promotion of H2 adsorption and storage.