Surface engineering of TiO2-MWCNT nanocomposites towards tuning of functionalities and minimizing toxicity

Mojca Božič, Irena Ban, Silvo Hribernik, Darinka Fakin, Karin Stana Kleinschek

Publikation: Beitrag in einer FachzeitschriftArtikelForschungBegutachtung

Abstract

Abstract: Multiwall carbon nanotubes were coupled with titanium dioxide (in different mole ratios of titanium and carbon) at the nano-scale, using a simple sonochemical and calcination process. The titanium dioxide-multiwall carbon nanotubes nanocomposites were for the first time surface modified with an innovative biotechnology-based reaction by using laccase to activate and covalently graft gallic acid dimers/oligomers/polymers on the nanocomposite surface in order to impart new functionalities and to minimize the nanocomposites’ toxicity. Structure of the titanium dioxide-multiwall carbon nanotubes, before and after surface modification, was investigated with X-ray powder diffraction, infrared, and UV-visible diffuse reflectance spectroscopy analysis, and scanning electron microscopy. The results indicated preferential formation of anatase titanium dioxide on one hand and covalent grafting of gallic acid dimers/oligomers/polymers functionalities on the nanocomposite surface, on the other. After modification, the antioxidant activity was analyzed using 2,2-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and photocatalytic activity toward the liquid-phase degradation of methylene blue in aqueous solution under both UV and visible light irradiation. Up to 98% antioxidant activity of the surface modified nanocomposites was established after 24 h of incubation, whereas non-modified nanocomposite induced the formation of the ABTS•+ radicals. In addition, 1.3-2.8-fold reduction in photocatalytic activity was achieved, depending on the irradiation. Accordingly, the gallic acid dimers/oligomers/polymers modified titanium dioxide-multiwall carbon nanotubes appear to simultaneously exhibit photocatalytic activity with an ability to scavenge free radicals, and can thus be considered as engineered nanoparticles with low toxicity.

Originalspracheenglisch
Seiten (von - bis)132-142
Seitenumfang11
FachzeitschriftJournal of Sol-Gel Science and Technology
Jahrgang83
Ausgabenummer1
DOIs
PublikationsstatusVeröffentlicht - 1 Jul 2017
Extern publiziertJa

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    ASJC Scopus subject areas

    • !!Electronic, Optical and Magnetic Materials
    • !!Ceramics and Composites
    • !!Chemistry(all)
    • !!Biomaterials
    • !!Condensed Matter Physics
    • !!Materials Chemistry

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