TiO2-graphene nanocomposite supported on floating autoclaved cellular concrete for photocatalytic removal of organic compounds

Photocatalytic titanium dioxide (TiO2) nanocomposites with different loads of ozonated graphene (OGn) were prepared and evaluated in the photocatalytic degradation of methylene blue, methyl orange and ketoprofen using UVC irradiation. The nanocomposites were characterized by field emission gun scanning electron microscopy (FEG-SEM), Raman spectroscopy, X-ray diffraction (XRD) and thermogravimetric analysis (TGA-DTA) and the specific surface area was determined by the Brunauer-Emmett-Teller (BET) method. The nanocomposites showed better photocatalytic activity than bare TiO2 due to the enhanced adsorption and the graphene property of inhibiting recombination between photogenerated electrons and holes. The composite containing 8% wt. OGn (TiO2-OGn-8%) was supported on autoclaved cellular concrete (ACC) creating a floating photocatalytic nanocomposite. This floating material was evaluated for successive cycles in the degradation of methylene blue, methyl orange and ketoprofen solutions. Although the photocatalytic activity decreased with each cycle, it is possible to reuse the nanocomposite satisfactorily and this facilitates its practical application for water treatment.