Anatase TiO2 film with dominant (001) facets prepared by radio frequency atmospheric pressure plasma

Anatase TiO2 nanosheets film with dominant (001) facets (TF-1) has attracted widespread research interest owing to wide-ranging industrial applications and fundamental importance. In this work, we prepared TF-1 with well adhesion on quartz substate in a short time (20 min) by radio frequency (RF) pulse-modulated plasma with hydrofluoric acid (HF) as the morphology controlling agent (MCA). Many intercrossed nanosheets were observed on the surface of TF-1 through SEM images, which provides more exposed reactive (001) facets. The degree of truncation (B/A) and the percentage of exposed (001) facets (S001/S) were estimated by XRD patterns and Raman spectra, which have been increased due to the presence of HF. XPS results indicate that F atoms are only adsorbed on anatase surface rather than doped into TiO2 lattice. The functions of HF on the growth of anatase TiO2 nanosheets were studied by density functional theory (DFT), revealing the stabilization effects associated with chemisorbed fluorine (F) atoms over (001) surface, and thus stimulating its preferred growth.