Nanopatterned zinc titanate thin films prepared by the evaporation-induced self-assembly process

Abstract

Nanopatterned thin films prepared by the evaporation-induced self-assembly process have up to now been limited to a few transition metal oxides (i.e. Al2O3, TiO2 and ZrO2). Here we describe the formation of zinc titanate nanoperforated thin films with different Zn/Ti ratios using the dipcoating process. Atomic force microscopy and scanning electron microscopy reveal that the structure consists of well-ordered pseudohexagonal nanoperforations in the range of 30nm in diameter separated by 25nm wide metal oxide ridges, while the film thickness is close to 2nm. For films with a zinc precursor content up to 50mol%, the well-organized structure of the thin film can be maintained, while at higher Zn contents the nanostructure is gradually becoming more disordered, which we have shown is consistent with the partial charge model. Grazing incidence X-ray diffraction measurements on the films calcined at 700°C indicate that the anatase phase of the pure TiO2 films is gradually consumed at the expense of a newly formed Zn2Ti3O8 phase upon increasing the Zn/Ti ratio in the starting precursor solution. The unique combination of the nanostructure with the zinc titanate composition grants these nanopatterned thin films significant application prospects in for instance optics and catalysis.