TeO2 nanostructures as a NO2 sensor: DFT investigation

The structural stability, electronic properties and adsorption characteristics of NO2 on TeO2 nanostructures are studied using density functional theory. Pure, Se and F substituted TeO2 nanostructures are optimized utilizing B3LYP/LanL2DZ basis set. Structural stability of TeO2 nanostructures are discussed in terms of calculated energy. The electronic properties of TeO2 nanostructures are analyzed with HOMO-LUMO gap, ionization potential and electron affinity. Dipole moment and point symmetry of TeO2 nanostructures are also reported. The outcome of the present work gives clear insights to the adsorption characteristics of NO2 on TeO2 nanostructures. NO2 adsorption characteristics can be fine-tuned through proper substitution impurity such as Se and F on TeO2 nanostructures. The adsorption characteristics of NO2 on TeO2 are also discussed by Mulliken population analysis and density of states spectrum. The possible adsorption sites of NO2 on TeO2 nanostructure are identified. The impurity substituted TeO2 nanostructures enhance the sensing characteristics towards NO2 in mixed gas environment. (C) 2014 Elsevier B.V. All rights reserved.