Efficient Photocatalytic Degradation of Norfloxacin in Aqueous Media by Hydrothermally Synthesized Immobilized TiO2/Ti Films with Exposed {001} Facets.

ABSTRACT

In this study, a novel immobilized TiO2/Ti film with exposed {001} facets was prepared via a facile one-pot hydrothermal route for the degradation of norfloxacin from aqueous media. The effects of various hydrothermal conditions (i.e., solution pH, hydrothermal time (HT) and HF concentration) on the growth of {001} faceted TiO2/Ti film were investigated. The maximum photocatalytic performance of {001} faceted TiO2/Ti film was observed when prepared at pH 2.62, HT of 3 h and at HF concentration of 0.02 M. The as-prepared {001} faceted TiO2/Ti films were fully characterized by field-emission scanning electron microscope (FE-SEM), X-ray diffraction (XRD), high resolution transmission electron microscope (HR-TEM), and X-ray photoelectron spectroscopy (XPS). More importantly, the as-prepared {001} faceted TiO2/Ti film exhibited excellent photocatalytic performance toward degradation of norfloxacin in various water matrices (Milli-Q water, tap water, river water and synthetic wastewater). The individual influence of various anions (SO42-, HCO3-, NO3-, Cl-) and cations (K+, Ca2+, Mg2+, Cu2+, Na+, Fe3+) usually present in the real water samples on the photocatalytic performance of as-prepared TiO2/Ti film with exposed {001} facet was investigated. The mechanistic studies revealed that •OH is mainly involved in the photocatalytic degradation of norfloxacin by {001} faceted TiO2/Ti film. In addition, norfloxacin degradation byproducts were investigated, on the basis of which degradation schemes were proposed.