NH3 on a BC3 nanotube: effect of doping and decoration of aluminum

The adsorption of the NH₃ molecule was investigated on pristine, Al-doped and Al-decorated BC₃ nanotubes (BC₃NT) using density functional theory calculations. It was found that NH₃ prefers to be adsorbed on a B atom of the tube wall, releasing energy of 1.02 eV. Al-doping increases the acidity of the tube surface and, therefore, its reactivity toward NH₃ so that the released energy in this case is about 1.62 eV, while decorating the BC₃NT with Al atom decreases the acidity and reactivity. Although Al-doping has no significant effect on the electronic properties of the BC₃NT, Al-decoration significantly reduces its HOMO/LUMO energy gap from 2.37 to 1.16 eV so that the tube becomes an n-type semiconductor. However, we believe that the acidity of the BC₃NTs may be controlled by doping or decoration of Al atoms.