Ab initio studies of the interaction of formaldehyde with beryllium oxide nanotube

The interaction of a formaldehyde molecule with a BeO nanotube was explored by means of density functional calculations. It was found that formaldehyde prefers to be adsorbed on a Be-O bond of the tube wall with the change of Gibbs free energy of 18.9 kcal/mol at 1 atm and 298 K. This adsorption process significantly shifts the lowest unoccupied molecular orbital of the tube to lower energies, thereby reducing the gap of the tube from 7.04 to 4.19 eV. It suggests that BeO nanotube may generate an electrical signal in the presence of formaldehyde molecule because of the conductance change. Also, we investigated the effect of humidity on this sensor. (C) 2014 Elsevier B.V. All rights reserved.