NiO nanocone as a CO sensor: DFT investigation

Adsorption properties of CO molecule on NiO nanocone were investigated using density functional approach in terms of adsorbed energy, structural, and electronic properties. The results of the present study reveal that the favorable adsorption site for CO molecule is to the oxygen atom on the apex of NiO nanocone. The adsorbed energy on the apex of oxygen atom in nanocone is found to be -8.432 eV. The average variation in the energy gap is found to be 50 % for CO adsorption on apex of oxygen atom. The Mulliken population analysis and density of states also confirm the adsorption of CO on to the oxygen atom in the apex of nanocone. The present result provides the insight to fine-tune the sensing properties of CO on to the NiO nanocone and enhance the sensing properties.