Author(s)

A. A. El-Barbary^1,2*, Kh. M. Eid^1,3, M. A. Kamel¹, H. O. Taha¹, G. H. Ismail^1,2

¹Physics Department, Faculty of Education, Ain Shams University, Cairo, Egypt.
²Physics Department, Faculty of Science, Jazan University, Jazan, KSA.
³Bukairiayh for Science, Qassim University, Qassim, KSA.

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.

CNT-BNNT Heterojunctions, DFT, Gas Sensors

El-Barbary, A. , Eid, K. , Kamel, M. , Taha, H. and Ismail, G. (2015) Adsorption of CO, CO₂, NO and NO₂ on Carbon Boron Nitride Hetero Junction: DFT Study. Journal of Surface Engineered Materials and Advanced Technology, 5, 169-176. doi: 10.4236/jsemat.2015.54019.