Reactivity Screening of Anatase TiO_2NanotubesArray and Anatase Thin Films: A Surface ChemistryPoint of View

摘要

As a reactivity screening we collected thermal desorptionspectroscopy (TDS) data of iso-butane, 02, CO2, and COadsorbed on an ordered TiO2 nanotubes (TiNTs) array. As areference system iso-butane adsorption on an anatase TiO2 thinfilm has been considered as well. The as-grown TiNTs arevertically aligned and amorphous. Polycrystalline (poly.)anatase or poly. anatase/rutile mixed nanotubes are formed byannealing confirmed by x-ray diffraction (XRD) and scanningelectron microscopy (SEM). The anatase thin film was grownon SrTiO3(001) and characterized by XRD and atomic forcemicroscopy (AFM). Surprisingly, oxygen distinctly interactswith the TiNTs whereas this process is not observed on fullyoxidized single crystal rutile Ti02(110). Desorptiontemperatures of 110-150 K and 100-120 K were observed forCO2 and CO, respectively, on the TiNTs. Variations in thebinding energies of the alkanes on TiNTs and anatase thinfilms also were present, i.e., a kinetic structure-activityrelationship (SAR) is evident.