Sensing properties of doped zigzag CNT and BNNT towards CO: A first principles study

Adsorption of CO molecules on pristine and doped zigzag CNT and BNNT was investigate applying density functional theory. Electronic and structural properties of this adsorption is report. Our result indicate that CO is not adsorbed on pristine CNT and has a weak adsorption energy on pure BNNT. However, in order to increase the response of CNT and BNNT to gas molecules they could be modified in a variety of ways such as defect formation, doping and hybrid structures. Therefore, we investigated the adsorption of CO molecules on C doped BNNT as well as B/N doped CNT. The results indicate that doped CNT and doped BNNT show higher sensitivity to CO molecules and could be considered as promising materials for CO detection. The best sites for CO adsorption are on the top of B atom in a B doped CNT and on the top of C atom in a C
_N
doped BNNT.