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With graphite oxide (GO) as the main raw material, combining with carboxymethyl cellulose (CMC), hydrothermal reduction combined ice template method was used to prepare graphene/carboxymethyl cellulose composite aerogel (HGA/CMC), through drying under the environmental pressure and hydrophobic modification. The HGA/CMC was characterized through SEM, FT-IR, XPS and microcomputer controlled electronic universal testing machine, which proves the successful combination between GO and CMC and the effective hydrophobic modification. HGA/CMC can absorb pure oil because of its abundant pore structure, the adsorption capacity of oil is 70.28-172.78 g·g-1, and the higher the oil density is, the greater the oil mass can be adsorbed by aerogel per unit mass. Furthermore, HGA/CMC shows good selective adsorption capacity for floating oil on water, heavy oil on water bottom and emulsified oil in water. HGA/CMC can be recycled by mechanical extrusion, and its adsorption capacity loss is only 15% after 10 times of extrusion regeneration. It is an oily wastewater treatment material with application potential.

Nitrogen-doped TiO2 and reduced graphene oxide (RGO) nanocomposites (NTG) were prepared by sol-gel method followed by annealing treatment process under N2 atmosphere. The as-prepared NTG nanocomposite were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FT-IR) and ultraviolet-visible diffuse reflectance spectroscopy (DRS). The results indicate that the incorporation of nitrogen onto both RGO and TiO2 was accomplished simultaneously in the facile process. Nitrogen doping makes the light excitation range red shift and can enhance the electron-hole separation effectively. The photocatalytic activity of the as-prepared samples was evaluated through the degradation of methyl orange (MO) under visible light irradiation. The introduction of nitrogen increased the photodegradation activity, which can be indicated by the fitted apparent first-order kinetics rate constant k, increasing about four times from 0-NTG-450 to 15-NTG-450. The annealing treatment further increased the photodegradation activity about 1.5 times of 15NTG-450 for 15NTG-800. [ABSTRACT FROM AUTHOR]

Pickering emulsion were used as soft template for the preparation of two different kinds of graphene-based aerogels (graphene aerogels, named AGAs and graphene/polyvinyl alcohol (PVA) aerogels, named BGAs) in this work. The Pickering emulsions show good control effect on the pore sizes, density and porosity of the two kinds of graphene-based aerogels. The increase of the oil/water ratio in the emulsion can leads to increase of pore size and porosity and decrease of density of AGAs and BGAs. And the increase of agitation speed during the emulsion preparation leads to the decrease of the pore sizes of AGAs and BGAs, while shows slight influence on the porosity and density of the materials. Volume filling behavior was found when AGAs and BGAs adsorbing organics, so it is considered that high porosity and high open pore fraction in the aerogels will favor the adsorption capacity on organics. [ABSTRACT FROM AUTHOR]

As a two-dimensional carbon-based nano-material, graphene has wide optical absorption range, high specific surface area, excellent thermal conductivity and mechanical properties. In order to further enhance the light absorption performance of graphene and reduce the agglomeration between graphene sheets, one-dimensional carbon nanotubes are introduced through a simple hydrothermal reduction method to composite with graphene to obtain a three-dimensional graphene-based photothermal material. The specific suffice area of the photothermal material is significantly enhanced and the suffice becomes rougher. It has open microporous structure as well. The material is characterized and evaluated in desalination of artificial seawater. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier infrared spectroscopy (FTIR) and so on are used to characterize the material, and effective combination between graphene sheets and carbon nanotubes are observed. It is found that the light absorbance of graphene-carbon nanotube composite aerogel could reach 92 % in the range of 200-2500 nm through UV-vis-NIR spectrophotometer (UV-vis-NIR.) analysis. The evaporation rate of artificial seawater could reach 2.287 kg/(m² · h) when the composite aerogel is used for solar-steam generation, and the photothermal conversion efficiency could reach 96.88%. These results indicate that graphenecarbon nanotube composite aerogel has a good photothermal conversion performance, and would have a broad application prospect in seawater desalination. [ABSTRACT FROM AUTHOR]