Synthesis and Characterization of Titania−Graphene Nanocomposites

Abstract

In this work, the synthesis and physiochemical characterization of titanium oxide nanoparticle-graphene oxide (TiO 2 -GO) and titanium oxide nanoparticle-reduced graphene oxide (TiO 2 -RGO) composites was undertaken. TiO 2 -GO materials were prepared via the hydrolysis of TiF 4 at 60 °C for 24 h in the presence of an aqueous dispersion of graphene oxide (GO). The reaction proceeded to yield an insoluble material that is composed of TiO 2 and GO. Composites were characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), Raman spectroscopy, N 2 adsorption-desorption, and thermal gravimetric analysis/differential thermal analysis (TGA/DTA). This approach yielded highly faceted anatase nanocrystals with petal-like morphologies on and embedded between the graphene sheets. At higher GO concentrations with no stirring of the reaction media, a long-range ordered assembly for TiO 2 -GO sheets was observed due to self-assembly. GO-TiO 2 composites formed colloidal dispersions at low concentrations (∼0.75 mg/mL) in water and ethanol but were not amenable to forming graphene papers via filtration through Anodisc membranes (0.2 µM pore diameter) due to their high titania concentration. Zeta potential measurements and particle size distributions from dynamic light scattering (DLS) experiments on these materials explain the stability of the TiO 2 -GO colloidal solutions. Chemical and thermal methods were also used to reduce TiO 2 -GO to give TiO 2 -RGO materials.

Graphene supported plasmonic photocatalyst for hydrogen evolution in photocatalytic water splitting

“…In the present study, the Raman analysis reveals the shift in G-band from 1597 to 1587 cm -1 and the D-band from 1351 to 1321 cm -1 after TiO 2 loading. These shifts are consistent with the previous reports [38,39]. Moreover, the 2D band at around 2692 cm -1 is also observed (see Fig.…”

Preparation and photocatalytic activity of graphene-modified Ag2S composite

“…[25] In general, when GO is reduced to graphene, the Raman peaks of G-and D-bands would shift to lower values. [25,26] A similar shift emerges in the Raman spectrum of 4% GR/Ag 2 S: the D-band shifted from 1601 to 1582 cm ¡1 , while G-band shifted from 1326 to 1319 cm ¡1 , which proves the existence of GR in the hybrids. Meanwhile, an increased intensity ratio of two peaks of GR (ID/IG) is observed compared with that of GO.…”

TiO2-graphene nanocomposite for electrochemical sensing of adenine and guanine

“…It has been demonstrated that graphene oxide is heavily oxygenated, bearing hydroxyl and epoxide groups on its basal planes and carboxyl groups at the sheet edges [44]. These oxygen containing groups can effectively interact with the hard Ti 4+ Lewis acid, which promotes the intercalation of Ti species into graphene oxide layers [27,28]. Afterwards, under the hydrothermal process, graphene oxide can be reduced to graphene with in situ immobilization of TiO 2 nanoparticles on the resultant graphene sheets.…”

“…This biosensor exhibited good direct electrochemistry without any electron mediator, as well as good sensitivity and fast response time towards glucose detection [24]. On the other hand, the photophysical and electrochemical properties of TiO 2 have shown to be greatly improved in TiO 2 -graphene hybrid materials [14,[25][26][27][28]. Li and coworkers observed significant enhancement in the reaction rate using TiO 2 -graphene as photocatalyst for photodegradation of methylene blue [25].…”