Abstract
We have presented a density functional theory study of the adsorption properties of NO2 and O3 molecules on heterostructured TiO2/ZnO nanocomposites. The most stable adsorption configurations, adsorption energies and charge transfers were calculated. The electronic properties of the complex TiO2/ZnO heterostructures were described using the density of states and molecular orbital analyses. For NO2 adsorption, it was found that the oxygen atoms preferentially move towards the fivefold coordinated titanium atoms, whereas the nitrogen atom binds to the zinc atom. In the case of O3 adsorption, the side oxygen atoms bind to the fivefold coordinated titanium sites, and the central oxygen atom does not contribute to the adsorption any longer. Thus, the interaction of NO2 and O3 molecules with TiO2 side of nanocomposite is strongly favored. On the N-doped TiO2/ZnO nanocomposites, the adsorption process is more energetically favorable than that on the pristine ones. The N-doped nanocomposites are far more sensitive to gas detection than the undoped ones. In TiO2/ZnO nanocomposites, the interactions of gas molecule and TiO2 are stronger than those between gas molecule and bare TiO2 nanoparticles, which reveals that ZnO is conducive to the interaction of NO2 and O3 molecules with TiO2 nanoparticles. Our theoretical results suggest multicomponent TiO2/ZnO nanocomposite as a potential material for gas sensing application.Graphical
Highlights
Titanium (Ti) and titanium alloys are some of the most important biomedical materials because of their biocompatibility, good mechanical properties, and outstanding corrosion resistance [1, 2]
We have performed a theoretical study of NO2 and O3 molecules on the TiO2/ZnO nanocomposites using density functional theory (DFT) calculations
These adsorptions are carried out on the pristine and N-doped nanocomposites. We found that both these molecules are chemisorbed on the nanocomposite surface, representing a bridge geometry of the gas molecule at the interface region
Summary
Titanium (Ti) and titanium alloys are some of the most important biomedical materials because of their biocompatibility, good mechanical properties, and outstanding corrosion resistance [1, 2]. It is well known that the surface of titanium atom possesses an excellent ability to be spontaneously oxidized into titanium oxide. J Nanostruct Chem (2017) 7:345–358 surface property of TiO2 is related to the excellent biocompatibility of the titanium atom [3]. There are three important polymorphs of TiO2, rutile, anatase, and brookite [9] It possesses a wide band gap in the range of 3–3.2 eV, which prominently reduces its capability to be utilized in photocatalytic reactions. This wide band gap restricts the photosensitivity of TiO2 to the ultraviolet (UV) region, decreasing the photocatalytic activity. Among different methods for improving the optical response of TiO2, non-metal doping is the most broadly used method to increase the photocatalytic activity of TiO2 [10, 11]
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call