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Abstract
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Density functional theory calculations were carried out to investigate the adsorption behaviors of O3 molecules on the undoped and N-doped TiO2/MoS2 nanocomposites. With the inclusion of vdW interactions, which correctly account the long-range dispersion energy, the adsorption energies and final geometries of O3 molecules on the nanocomposite surfaces were improved. For O3 molecules on the considered nanocomposites, the binding sites were located on the fivefold coordinated titanium atoms of the TiO2 anatase. The structural properties of the adsorption systems were examined in view of the bond lengths and bond angles. The variation of electronic structures was also discussed in view of the density of states, molecular orbitals and distribution of spin densities. The results suggest that the adsorption of the O3 molecule on the N-doped TiO2/MoS2 nanocomposite is more favorable in energy than that on the pristine one, indicating that the N-doped nanocomposite has higher sensing capability than the pristine one. This implies that the N-doped TiO2/MoS2 nanocomposite would be an ideal O3 gas sensor. However, our calculations thus provide a theoretical basis for the potential applications of TiO2/MoS2 nanocomposites as efficient O3 sensors, leading to very interesting results in the context of air quality measurement.
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