title: Enhanced catalytic activity of the surface modified TiO2-MWCNT nanocomposites under visible light.
abstract: Fusing multiwall carbon nanotubes (MWCNTs) with TiO2 at the nano-scale level promotes the separation of those electron-hole charges generated upon UV and daylight irradiation. In this study, we investigated facile sonochemical synthesis, combined with the calcination process for the preparations of TiO2-MWCNT composites with different mole ratios of titanium and carbon. In order to produce stable nano dispersions we exploited an innovative biotechnology-based approach for the covalent functionalizations of TiO2-MWCNTs with in-situ synthesized soluble phenoxazine dye molecules. The none and functionalized TiO2-MWCNTs composites were analyzed by a range of analytical techniques including XRD, Raman, XPS, SEM and UV-vis diffuse reflectance spectroscopy (DRS), and dynamic light scattering (DLS). The photocatalytic activity was evaluated toward the liquid-phase degradation of MB in aqueous solution under both UV and visible light irradiation. TiO2-MWCNTs with optimized mole ratio exhibit much higher photocatalytic activity and stability than bare TiO2. The as-prepared TiO2-MWCNTs photocatalyst possessed good adsorptivity of dyes, extended light absorption range and efficient charge separation properties simultaneously. The results indicated that the soluble phenoxazine dyes and amino-benzenesulfonic acid monomers were covalently grafted on to the surfaces of TiO2-MCNTs, which promoted good aquatic dispersibility and extended light absorption, resulting in increased photocatalytic efficiency.
authors.affiliation: University of Maribor, Institute for Engineering Materials and Design, Smetanova ulica 17, SI-2000 Maribor, Slovenia. Electronic address: mojca.bozic@um.si.
authors.forename: Mojca
authors.initials: M
authors.lastname: Božič
authors.affiliation: University of Maribor, Institute for Engineering Materials and Design, Smetanova ulica 17, SI-2000 Maribor, Slovenia.
authors.forename: Vera
authors.initials: V
authors.lastname: Vivod
authors.affiliation: University of Maribor, Institute for Engineering Materials and Design, Smetanova ulica 17, SI-2000 Maribor, Slovenia.
authors.forename: Robert
authors.initials: R
authors.lastname: Vogrinčič
authors.affiliation: University of Maribor, Faculty of Chemistry and Chemical Engineering, Smetanova ulica 17, SI-2000 Maribor, Slovenia.
authors.forename: Irena
authors.initials: I
authors.lastname: Ban
authors.affiliation: Institute Jožef Stefan, Jamova 39, SI-1000 Ljubljana, Slovenia.
authors.forename: Gregor
authors.initials: G
authors.lastname: Jakša
authors.affiliation: University of Maribor, Institute for Engineering Materials and Design, Smetanova ulica 17, SI-2000 Maribor, Slovenia.
authors.forename: Silvo
authors.initials: S
authors.lastname: Hribernik
authors.affiliation: University of Maribor, Institute for Engineering Materials and Design, Smetanova ulica 17, SI-2000 Maribor, Slovenia.
authors.forename: Darinka
authors.initials: D
authors.lastname: Fakin
authors.affiliation: University of Maribor, Institute for Engineering Materials and Design, Smetanova ulica 17, SI-2000 Maribor, Slovenia.
authors.forename: Vanja
authors.initials: V
authors.lastname: Kokol
keywords: Carbon nanotube; Extended light photocatalysis; Laccase; Surface functionalization; TiO(2)