Comparative theoretical study of iron and magnesium incorporated porphyrin induced carbon nanotubes and their interaction with hydrogen molecule

The Density Functional Theory calculations are employed to investigate the formation energies and electronic properties of metal (magnesium and iron)-porphyrin induced carbon nanotubes (CNTs). It is found that the incorporation of four-nitrogen divacancy (4ND) defect in CNT resulted in a decreased value of band gaps. Dispersing 4ND defective nanotubes with Fe or Mg resulted in their strong binding over nanotubes, with binding energies of −7.84 eV and −4.273 eV, respectively and thus suggesting a reduction of clustering of metal atoms over metal decorated CNT. Fe–PICNT shows very strong binding to H2 as compared to its contemporary Mg–PICNT for storing hydrogen, the NBO, CDA and PDOS analysis are also reported.

► Materials based on biological organic molecules are explored for hydrogen storage. ► Iron and magnesium incorporated porphyrin induced CNTs are investigated using DFT. ► Their formation, stability and interaction with hydrogen molecule are studied. ► Strong interaction of hydrogen molecule with Fe–PICNT has been found.