TITLE:
Adsorption of CO, CO2, NO and NO2 on Carbon Boron Nitride Hetero Junction: DFT Study
AUTHORS:
A. A. El-Barbary, Kh. M. Eid, M. A. Kamel, H. O. Taha, G. H. Ismail
KEYWORDS:
CNT-BNNT Heterojunctions, DFT, Gas Sensors
JOURNAL NAME:
Journal of Surface Engineered Materials and Advanced Technology,
Vol.5 No.4,
July
16,
2015
ABSTRACT: The adsorption of CO, CO2, NO and CO2 gas molecules on different diameters and chiralities of carbon
nanotube-boron nitride nanotube (CNT-BNNT) heterojunctions is investigated, applying the
density functional theory and using basis set 6 - 31 g (d,p). The energetic, electronic properties
and surface reactivity have been discussed. We found that the best CNT-BNNT heterojunctions for
adsorbing the CO, NO, CO2 and NO2 gas molecules is (5,0) CNT-BNNT heterojunction through forming
C-N bonds with adsorption energy of -0.26, -0.41 eV, -0.33 and -0.63 eV, respectively. Also,
the adsorption of CO, NO, CO2 and NO2 gas molecules on (5,5) and (6,6) CNT-BNNT heterojunctions
does not affect the electronic character of the CNT-BNNT heterojunctions, however the adsorption
of NO and NO2 gas molecules on (5,0) and (9,0)CNT-BNNT heterojunctions in case of forming C-B
bonds increases the band gaps to 1.21 eV and 1.52 eV, respectively. In addition, it is reported that the
values of dipole moment for armchair (5,5) and (6,6) CNT-BNNT heterojunctions are not affected by
gas adsorption. Also, for the zig-zag (5,0) and (9,0) CNT-BNNT heterojunctions, the values of dipole
moment increase through forming C-N bonds and decrease through forming C-B bonds. In addition,
it is reported that the highest dipole moment is obtained for (9,0) CNT-BNNT heterojunctions. Therefore,
the zig-zag CNT-BNNT heterojunctions can be selected as good candidate for gas sensors.