Enhanced Removal Ciprofloxacin by Self-assembled Hydrogel with Anatase Titanium Oxide Nanotubes and Grapheme.

A novel hydrogel, consisting of titanium dioxide nanotubes and graphene oxide (H-TN-GO), was fabricated to remove ciprofloxacin (CIP) from aqueous solution. The adsorbent was characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. Batch adsorption experiments systematically investigated the effect of contact time, temperature and pH on the capacity of H-TN-GO for CIP. Adsorption property of H-TN-GO and its regeneration performance was evaluated. H-TN-GO exhibited high adsorption capacity of 530 mg/g and Langmuir model was more suitable for fitting adsorption behavior. The removal ratio of CIP was more than 99% when initial concentrations were less than 100 mg/L. Besides, the initial pH of CIP solution had a distinct influence on the removal ratio, and adsorption capacity of adsorbance could be recovered by regeneration with mild alkaline condition. Large pore size and abundant oxygen-containing groups on the surface further improved its adsorption performance. The enhancing effect of H-TN-GO mainly attributed to the immobilization of TiO₂ onto graphene oxide and π-π interactions stacking between H-TN-GO and graphene oxide. As potential adsorbents, H-TN-GO exhibited remarkable regeneration capacity for water treatment. [ABSTRACT FROM AUTHOR]