Hydrogen adsorption on BN-embedded tetrabenzopentacene as a promising nanoflake for energy storage: Theoretical insights

The recently synthesized BN-embedded tetrabenzopentacene (BNTBP) molecule has been theoretically studied as a potential candidate for hydrogen storage. The decoration with Li cations has been performed for the enhancement of the hydrogen uptake. DFT and SAPT0 calculations reveal that up to four hydrogen molecules per Li+ have adsorption energy (Ead) of −3.03 to −4.98 kcal/mol, which is close to the optimal range; it is necessary for effective sorption/desorption. The assessed hydrogen capacity of Li+-decorated BNTBP is 4.8 wt%. It has been confirmed that induction and electrostatic interactions play the major role for H2 adsorption in the present case, whereas dispersion ones contribute into Ead very moderately. AIM and IGM analyses have shown that there is non-covalent bonding between Li+ and H2, and the H2 molecules being adsorbed are undissociated ones. Our investigations establish the high potential of Li+-decorated BNTBP for hydrogen storage. [Display omitted] •BN-embedded tetrabenzopentacene as a nanoflake for hydrogen adsorption is modeled.•Li+-decoration substantially improves hydrogen adsorption.•SAPT0 reveals that H2 adsorption is mainly due to Eind and Eel interactions.•H2 uptake capacity is as per the 2020 US DOE target for vehicles.