Effects of Al Doping and Double-Antisite Defect on the Adsorption of HCN on a BC2N Nanotube: Density Functional Theory Studies

By using density functional theory, we investigated the reactivity and electronic sensitivity of pristine and structurally manipulated BC2N nanotubes (BC2NNT) to a HCN molecule. It was mainly found that (i) the pristine BC2NNT can weakly adsorb the HCN with adsorption energy of -1.1 kcal/mol, and its electronic properties are not sensitive to HCN; (ii) doping the tube by an Al atom can largely improve its reactivity to HCN, but it does not have a significant effect on its sensitivity; (iii) B-B antisite defect on the tube wall can improve both reactivity and sensitivity of the tube to HCN; (iv) N-N antisite could improve neither the reactivity nor the sensitivity. Upon the adsorption of HCN on the B-B antisite defect, the HOMO-LUMO energy gap of the tube is significantly reduced from 2.23 to 1.82 eV and energy of 6.3 kcal/mol is released.