Cu-induced activation of borophene for efficient hydrogen storage: a combined DFT and AIMD investigation

Using first-principles calculations and ab initio molecular dynamics, we studied hydrogen adsorption on pristine borophene and on borophene supported by a Cu(111) surface. Pristine β₁₂ borophene was found to be metallic, thermally stable, and able to host hydrogen with a gravimetric density of 11.06 wt%, above the U.S. DOE target. However, the interaction with hydrogen was weak, with adsorption energies in the physisorption range and desorption temperatures mostly below room temperature. When supported on Cu(111), the interaction became much stronger. The Cu substrate donates charge to borophene and promotes hybridization between H-s, B-p, and Cu-d states, leading to dissociative adsorption, higher desorption temperatures (706-749 K), and a gravimetric density of 7.08 wt%. These results show that borophene has potential for hydrogen storage, with pristine sheets offering light-weight capacity and Cu-supported sheets enabling stronger, catalytic adsorption.