A DFT study of interaction of hydrogen molecules and (5,5) carbon nanotube with bioinspired functionalization

All electron density functional theory (DFT) calculations have been carried out for calcium-doped porphyrin-incorporated(5, 5) carbon nanotube (Ca-PICNT) to investigate the formation energies, electronic properties of this system, andits application in hydrogen storage. It is found that the incorporation of porphyrin ring in carbon nanotube led toa decreased value of the highest occupied molecular orbital and lowest unoccupied molecular orbital gap and astrong binding of Ca over nanotube and consequently resulted to a drastic reduction of clustering of Ca atomover Ca-decorated carbon nanotube. The Ca-PICNT can bind a maximum of 4H2 with binding energy value of0.105 eV per H2 molecule. Charge decomposition analysis indicated that the mode of hydrogen storage is viacoulomb-electrostatic force, which is further supported by the natural bond orbital and partial density-of-states studies.

Keywords:

Nitrogen divacancy , DFT , Partial density-of-states , CDA , NBO