Hydrogen adsorption on osmium and boron co-doped single walled carbon nanotubes for energy storage: A DFT study

The osmium and boron co-doped armchair single walled carbon nanotubes (SWCNTs) have been studied for hydrogen storage using ab-initio method. The calculations have been carried out using Gaussian software with Density functional theory. We have replaced a carbon atom by osmium atom in SWCNT & neighboring carbon atoms are replaced by boron atoms sequentially. In the present work, the hydrogen adsorption ability of osmium/ boron co-doped CNTs has been investigated on the basis of bond distances, variation of binding energy, chemical hardness, band gaps, charge distribution and adsorption energies. It is found that osmium/boron co-doping in SWCNTs enhanced the hydrogen storage capacity but increase of boron atom concentration in osmium doped SWCNT reduces the storage ability. The maximum hydrogen adsorption energy was calculated in case of osmium atom decorated single boron atom doped SWCNT (Os-BCNT) i.e. Eads -0.490 eV. And study reveal that osmium doped CNT (Os-CNT) and osmium/boron co-doped CNT (Os-BCNT) both can efficiently adsorb five hydrogen molecules at 298.15 Kelvin temperature/1 atm pressure.

Automated summary

This study investigates the effects of osmium and boron co-doping on hydrogen storage in carbon nanotubes using ab-initio calculations. The results show that osmium/boron co-doping enhances the hydrogen storage capacity, but an increase in boron atom concentration reduces the storage ability.