Selective Sensing Characteristics of Ca Doped BeO Nano-sized Tube toward H2O and NH3
Abstract
By means of density functional calculations, the structural and electronic properties of chemical modification of pristine and Ca-doped BeO nanotubes were investigated with NH3 and H2O molecules. It was found that the NH3 and H2O molecules can be adsorbed on the Be atom of the tube sidewall with the adsorption energies of about 36.1 and 39.0 kcal/mol, respectively. Density of states analysis shows that the electronic properties of the BeONT are slightly changed after the adsorption processes. Substitution of a Be atom in the tube surface with a Ca atom increases the adsorption energies by about 7.4 and 14.7 kcal/mol for NH3 and H2O, respectively. Unlike the pristine tube, the electronic properties of Ca-doped BeONT are sensitive to NH3 and H2O molecules. Also, the Ca-doped tube is much more sensitive to H2O molecule than NH3 one.