Ab initio characterization of Ti decorated SWCNT for hydrogen storage

Characterization has been performed on basis of several physicochemical parameters. The results indicate that the preferential adsorption is on Ti atom deposited on the top site of the (5,5) armchair SWCNT with energies (−0.44 and −0.71) eV for H2 oriented parallel to the (x) and (y) axes respectively. The binding of H2 is mostly dominated by the support-metal E (i)S⋯Ti term. The role of the SWCNT is not restricted to support the metal. Significant reduction of the energy gap is observed when H2 are anchored on the external surface of the SWCNT. The SWCNT⋯Ti⋯H2(x) complex is the least reactive configuration with nucleophiles. The calculated parameters characterize H2 that is oriented parallel to the (x)-[100] axis of the SWCNT to be the most suitable configuration for hydrogen storage based on the recommended adsorption energy range of DOE (−0.2 to −0.6) eV.

► Physisorption interaction of H2 with Ti decorated SWCNT at different sites.
► Characterization in terms of structure, energetic, and spectral properties.
► Preferential adsorption is on top site with energies −0.44, −0.71, and +0.27 eV.
► The study characterizes H2 that is parallel to the (x) axis to be the most suitable.