Covalent functionalization of AlN nanotubes with acetylen

Covalent functionalization of a zigzag AlN nanotube (AlNNT) with acetylene molecule has been investigated using density functional theory in terms of energetic, geometry and electronic properties. The obtained results show that the acetylene preferably tends to [2+2] addition on Al–N bonds of the tube surface releasing energies in the range of 1.02 to 1.10 eV along with a charge transfer from the tube to the acetylene. We have found that HOMO–LUMO gap of AlNNT has not changed significantly upon the functionalization and, its global hardness and electrophilicity are slightly decreased. Also, it has been revealed that the field electron emission from the AlNNT surface may be improved upon the adsorption of acetylene due to decrease of work function ascribed to the charge transfer from the tube to the acetylene.