Sonochemical synthesis of TiO2 nanoparticles on graphene for use as photocatalyst

Abstract

Using ultrasonication we succeed in a controlled incorporation of TiO(2) nanoparticles on the graphene layers homogeneously in a few hours. The average size of the TiO(2) nanoparticles was controlled at around 4-5 nm on the sheets without using any surfactant, which is attributed to the pyrolysis and condensation of the dissolved TiCl(4) into TiO(2) by ultrasonic waves. The photocatalytic activity of the resultant graphene-TiO(2) composites containing 25 wt.% TiO(2) is better than that of commercial pure TiO(2). This is partly due to the extremely small size of the TiO(2) nanoparticles and partly due to the graphene-TiO(2) composite structure consisting of homogeneous dispersion of crystalline TiO(2) nanoparticles on the graphene sheets. As the graphene in the composites has a very good contact with the TiO(2) nanoparticles it enhances the photo-electron conversion of TiO(2) by reducing the recombination of photo-generated electron-hole pairs.

Enhanced thermal and mechanical properties of epoxy composites by mixing thermotropic liquid crystalline epoxy grafted graphene oxide

“…The modified Hummers method [24][25][26] was utilized to oxidize nature flake graphite for the synthesis of GO. The detailed processing is described as following: in a pretreatment step, K 2 S 2 O 8 (10 g) and P 2 O 5 (10 g) were mixed with H 2 SO 4 (98%, 80 mL) in a 500 mL beaker placed in water bath.…”

Facile hydrothermal preparation of titanium dioxide decorated reduced graphene oxide nanocomposite

“…Furthermore, other reported techniques that use hazardous chemicals, such as hydrazine hydrate, create dangerous by-products such as hydrogen fluoride. 42 Other reported problems in the formation of graphene nanocomposites include the lack of discrete nanocrystalline TiO 2 particles before calcination 43 and agglomeration of the TiO 2 particles. 44,45 In this paper, a one-step hydrothermal route for the preparation of graphene/TiO 2 nanocomposites using graphene oxide (GO) and titanium isopropoxide as starting materials with the addition of triethanolamine (TEA) is reported.…”

Enhanced photocatalytic degradation of a phenolic compounds’ mixture using a highly efficient TiO2/reduced graphene oxide nanocomposite

“…Figure 2c and d shows the FT-IR spectra of commercial TiO 2 and rGOTi, respectively. Both spectra look similar where a strong broad absorption band at low frequency (below 1000 cm -1 ) was measured and ascribed to the vibration of Ti-O-Ti in TiO 2 [35,44,46,47]. The absorption band at 1633 cm -1 is due to the Ti-O-Ti stretching vibration [31] or the deformation of water molecules.…”

“…A peak at 1621 cm -1 can be assigned either to the C=C stretching band [30] or to the deformation of water molecules [31], while the absorption band between 1720 and 1736 cm -1 corresponds to the carboxylic and carbonyl groups [32][33][34]. Moreover, the absorption peaks at 1382-856 cm -1 are attributed to the epoxy and alkoxy groups [35][36][37][38][39]. A broad band between 3900 and 3500 cm -1 is ascribed to the O-H stretching of C-OH groups (from hydroxyl and/or carboxylic groups) and intercalated water molecules [30,38,40].…”