  The electronic properties of TiO$_2$ nanostructure are explored using density
functional theory. The adsorption properties of acetone on TiO$_2$
nanostructure are studied in terms of adsorption energy, average energy gap
variation and Mulliken charge transfer. The density of states spectrum and the
band structure clearly reveals the adsorption of acetone on TiO$_2$
nanostructures. The variation in the energy gap and changes in the density of
charge are observed upon adsorption of acetone on n-type TiO$_2$ base material.
The results of DOS spectrum reveal that the transfer of electrons takes place
between acetone vapor and TiO$_2$ base material. The findings show that the
adsorption property of acetone is more favorable on TiO$_2$ nanostructure.
Suitable adsorption sites of acetone on TiO$_2$ nanostructure are identified at
atomistic level. From the results, it is confirmed that TiO$_2$ nanostructure
can be efficiently utilized as a sensing element for the detection of acetone
vapor in a mixed environment.
