A first-principles study on the behavior of HCl inside SWCNT

The electronic and band structure for (14, 0) single wall carbon nanotube (SWCNT) with the HCl molecule and H2 molecule inside are investigated by using a first-principles method with the pseudopotential density functional theory (DFT). The calculated density of states and band structures can elucidate the differences for the behavior of HCl and H2 inside SWCNT. The HCl molecule has a binding energy about −0.24 eV when it is put inside a (14, 0) SWCNT. Compared to HCl molecule, H2 did not induce any obvious change in the band structure and electronic property. A direct band gap 0.71 eV is obtained with HCl molecule inside (14, 0) CNT, which is larger than the value for pure CNT and with H2 molecule inside (14, 0) SWCNT.