Iron-TiO2 pillared clay nanocomposites: Eco-friendly solutions for photocatalytic removal of organic and pathogen contaminants

The synthesis of modified natural bentonite by TiO2 nanoparticles and their photocatalytic and antibacterial applications were studied. The natural bentonite (NB) used in this work has been purified by acid treatment to obtain activated bentonite (AB). Then, the intercalation of AB by Fe3+ noted, as FeAB was prepared. TiO2 and the three nanocomposites (TiO2/NB, TiO2/AB and TiO2/FeAB) were synthesized via a sol-gel and hydrothermal process. TiO2 pillared clays showed an important photocatalytic properties compared to TiO2 nanoparticles alone for the degradation of Metoprolol tartrate (MET). Therefore, TiO2/FeAB were found to be the most effective photocatalyst. The materials were characterized by X-ray diffraction (XRD), Fourier transform infrared spec-troscopy (FTIR), scanning electron microscope (SEM) with energy dispersive spectroscopy (EDS) and BET (Brunauer-Emmett-Teller) method. The results of FTIR spectra was consistent with the DRX patterns. The SEM pictures reveal significantly larger particle aggregates, which correspond to bentonite and small particles, which belong to TiO2. The antibacterial activities of all samples was evaluated by using Escherichia coli (Gram-negative bacteria) and Staphylococcus aureus (Gram-positive bacteria). A considerably high bacterial inactivation was achieved within 1 h of visible light irradiation for E. coli colonies. However, in dark all the colonies of S. aureus were killed in the first 30 min.