Hydrothermally prepared graphene-titania nanocomposite for the solar photocatalytic degradation of methylene blue

Reduced graphene oxide–titania (rGO–TiO2) nanocomposites were prepared by hydrothermal method at different reaction temperatures and characterized by powder X-ray diffraction, transmission electron microscopy, micro-Raman spectroscopy, X-ray photoelectron spectroscopy, and photoluminescence spectroscopy techniques, respectively. The photocatalytic properties of the nanocomposites were investigated toward the degradation of methylene blue under natural sunlight. The rGO–TiO2 shows better photocatalytic activity due to the extended visible light absorption, excellent adsorptivity, and effective electron transfer process than the other controlled photocatalysts. In addition, rGO–TiO2 shows good sustainability after subjecting it to five consecutive cycles of photodegradation. This enhanced photocatalytic performance and good sustainability toward dye removal makes this rGO–TiO2 nanocomposite as a potential candidate for wastewater treatment in textile and dyeing industries

Highly efficient preparation of ZnO nanorods decorated reduced graphene oxide nanocomposites

A one-step method for the synthesis of zinc oxide/reduced graphene oxide (ZnO/rGO) nanocomposites by a hydrothermal technique is reported. This simple method involves a hydrothermal treatment of a solution comprising graphene oxide (GO), Zn(CH3COO)2.2H2O, NaOH and NH3.H2O. The concentration of GO as a starting material plays an important role in the density distribution of ZnO nanorods on the rGO sheets and on the percentage of the formation of ZnO/rGO nanocomposites. The resulting rod-like ZnO nanoparticles formed on the rGO sheets, in high density, has a potential in the gas sensing application

Synthesis and characterization of reduced graphene oxide / TiO2 nanocomposites as high performance photocatalyst / Betty Chang Yea Sze

A simple single stage approach, based on the hydrothermal technique, has been introduced to synthesize reduced graphene oxide-titanium dioxide (RGO/TiO2) nanocomposites. The titanium dioxide (TiO2) nanoparticles are formed at the same time as the graphene oxide (GO) is reduced to graphene. The triethanolamine (TEA) used in the process has two roles. It acts as a reducing agent for the GO as well as capping agent allowing the formation of titanium dioxide nanoparticles with a narrow size distribution (~20 nm). Transmission Electron Microscopy (TEM) micrographs show that the nanoparticles are uniformly distributed on the reduced graphene oxide (RGO) nanosheet. Thermogravimetric Analysis (TGA) analysis shows the nanocomposites have an enhanced thermal stability over the original components. The potential application for this technology was demonstrated by the use of RGO/TiO2 nanocomposites in the photodegradation of methylene blue (MB). A significant enhancement in the photodegradation rate of MB under natural solar light was observed with the as-prepared RGO/TiO2, compared to the commercial P25 and pure TiO2 synthesized using the same method. This is due to the excellent adsorptivity of dyes performed by RGO (~8 times more powerful) and also because of the reduced electron-hole pair recombination demonstrated by the as-prepared RGO/TiO2. Besides, the nanocomposites exhibit high recyclability. Overall, this work could provide new insights into the fabrication of a TiO2-carbon composite as high performance photocatalysts and facilitate their application in the environmental protection issues