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Graphite oxide has a complex structure that can be modified in many ways to obtain materials for a wide range of applications. It is known that the graphite precursor has an important role in the synthesis of graphite oxide. In the present study, the basal-plane surface of highly annealed pyrolythic graphite (HAPG) was oxidized by Hummers’ method and investigated by Raman spectroscopy and atomic force microscopy. HAPG was used as a graphite precursor because its surface after cleavage contains well-ordered millimeter-sized regions. The treatment resulted in graphite intercalation by sulfuric acid and blister formation all over the surface. Surprisingly, the destruction of the sp2-lattice was not detected in the ordered regions. We suggest that the reagent diffusion under the basal plane surface occurred through the cleavage steps and dislocations with the Burgers vector parallel to the c-axis in graphite.

To improve the desulfurization adsorption performance of the magnetic hybrid material Fe3O4/HKUST-1, an innovative adsorbent Fe3O4/GO/HKUST-1 was synthesized. The desulfurization performance of Fe3O4/GO/HKUST-1 increased 24%, and the adsorption capacity increased to 38.21 mg/g because of a higher surface area and higher porosity than the parent materials. Moreover, the desulfurization capacity of Fe3O4/GO/HKUST-1 decreased 10% after five adsorption desorption cycles. Therefore, excellent adsorption properties and reusability make Fe3O4/GO/HKUST-1 attractive in the field of fuel desulfurization. [ABSTRACT FROM AUTHOR]

Two complexes of bis(aminobenzoato)zirconium(IV) phthalocyanine and their graphite oxide-based composites were synthesized and characterized in respect of their photochemical properties. Structures of phthalocyanines were confirmed by Mass and infrared spectroscopies. The absorption and photoluminescence spectra were investigated to show various behavior of the complexes in different media (dimethyl sulfoxide and saline). Optical technique (monitoring variation of absorption spectra of diphenylisobenzofuran used as an indicator) was used to prove the generation of reactive oxygen species (ROS) by under light irradiation in the range of the first biological window. The photoactivity of the materials was compared and discussed in terms of their potential ability to be used in biomedical applications, for example, as photosensitizers in photodynamic therapy.

Peanut shells are agricultural solid waste abundantly available in China, but most of them are discarded or burned off in stacks, causing the resource dissipation and environmetal pollution. In this work, polyurethane sponge/graphite oxide/boronic acid functionalized metal-organic framework (PU/GO/BA-MOF) was formed via a three-in-one strategy, and then applied for selective adsorption and effective separation of cis -diol containing luteolin (LTL) from peanut shell coarse extract. Our three-in-one strategy was based on specific cis -diol moieties recognition function and exceptional chemical stability of GO/BA-MOF, and the PU sponge possessed the advantages of convenient adsorption-desorption process owing to its reversible “shape memory” effect. Additionally, PU/GO/BA-MOF can attain the adsorption capacity towards LTL six times than non- cis -diol structure. There was no significant change for the adsorption capacity of the PU/GO/BA-MOF, and the frameworks of PU/GO/BA-MOF did not collapse after it was reused five times. Compared with first cycle, the adsorption capacity loss is approximately 10.73% at fifth cycles. Subsequently, peanut shell coarse extract (85% LTL) was twice purified by PU/GO/BA-MOF, and the purification product (98% LTL) was successfully evaluated by MS-HPLC analysis and antibacterial test. Purified LTL (second time) have exhibited more excellent antibacterial effect and less impure peaks than purified LTL (first time). Therefore, the novel PU/GO/BA-MOF materials provided the effective way for the utilization of peanut shell as a source of flavone containing cis -diol structure. [ABSTRACT FROM AUTHOR]

Nanocomposite superabsorbent hydrogels (NCSHs) were prepared via electron beam radiation-assisted polymerization using carboxymethylcellulose (CMC) and carbon materials as a superabsorbent polymer and additive inorganic nanomaterial, respectively. Carbon materials such as graphite oxide (GO), reduced graphene oxide (rGO), and activated carbon (AC) were used as additives. The chemical structure and morphology of the prepared NCSHs and pure superabsorbent hydrogels (SHs) were characterized using Fourier transform infrared spectroscopy and optical microscopy. In the prepared NCSHs, the carbon components were dispersed well in the CMC polymer matrix. The mechanical strength and gel fraction of the prepared materials were measured, and the swelling kinetics were evaluated using distilled water, urea solution, and physiological saline water. The prepared NCSHs using GO and rGO exhibited larger gel fraction and mechanical strength than the corresponding non-composite SHs. Electron beam radiation was more effective than solution polymerization in the syntheses of SHs and NCSHs with large gel fraction and high mechanical strength. The NCSHs prepared by electron beam radiation exhibited comparable swelling capabilities to those prepared by solution polymerization.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The synthesis and characterization of multifunctional cement and concrete composites filled with hexagonal boron nitride (h-BN) and graphite oxide (GO), is reported and their superior mechanical strength and oil adsorption properties compared to composites devoid of fillers are illustrated. GO is utilized to bridge the cement surfaces while h-BN is used to mechanically reinforce the composites and adsorb the oil. Introduction of these fillers even at low filler weight fractions increases the compressive strength and toughness properties of pristine cement and of porous concrete significantly, while the porous composite concrete illustrates excellent ability for water separation and crude oil adsorption. Experimental results along with theoretical calculations show that such nanoengineered forms of cement based composites would enable the development of novel forms of multifunctional structural materials with a range of environmental applications. [ABSTRACT FROM AUTHOR]

Abstract: This manuscript spans over 180years of ideas, discoveries, inventions, breakthroughs and research in Capacitive Deionisation (CDI) and Membrane CDI (MCDI) desalination. Starting with the first discovery of the dissociation of ions in solution under an electric field by M. Faraday (1833), through the pioneering work of carbon aerogel flow through capacitors by J. Farmer's group (1996) at Lawrence Livermore National Laboratory (LLNL), to the utilization of novel graphene and carbon nanotube (CNT) materials as electrodes, the CDI and MCDI technologies are progressively making its path to the desalination industry. Through this review various deficiencies of this technology have been identified, first and far most was the need for low cost and efficient electrode materials. The review identified that a low cost and high efficiency electrode capable of processing high salinity (seawater) stream still does not exists and is considered important if the technology is to make it to the industry. Furthermore, the lack of long term reliability, operation demonstrations and experience meant that information about scaling and fouling are rather scarce. Taking a step further, no comprehensive environmental assessment such as Life Cycle Assessment (LCA) or Environmental Impact Assessment (EIA) has been performed yet. [Copyright &y& Elsevier]

The graphite oxide (GO) was prepared based on the modified Hummers method, then reacted with zinc acetate aqueous, sodium hydroxide aqueous and hydrazine hydrate, and was doped into ZnO eventually to form graphene doped ZnO, an alternative transparent conducting oxide (TCO) for solar cell applications. The samples were characterized by Raman spectrometer, X-ray diffractometer, Fourier transform infrared spectroscopy and scanning electron microscope, and compared with widely used aluminum doped ZnO (AZO) in resistivity and transmissivity. The results show that the transmissivity of graphene doped ZnO reaches the same level as that of AZO in visible light band. In ultraviolet light wave band, the transmissivity of graphene doped ZnO reaches as high as 50%, exceeding that of AZO which is only 20%. The resistivity of optimized graphene doped ZnO is 1.03 × 10 Ω · m, approaching AZO resistivity which is about 10-10 Ω ·m. As a result, graphene doped ZnO may have potential applications in the area of TCO due to its low cost and high performance. [ABSTRACT FROM AUTHOR]

Abstract: The last decade has seen a growing interest in hybrid electrically conducting nanocomposites. This article aims to provide a detailed overview of the present status of research in carbon nanotube–polyaniline (CNT/PANI) composites, from processing to structural and property evaluations. CNT/PANI are synthesized by electrochemical and chemical processing. When chemical methods are used, the main challenge is to obtain processable CNT/PANI in the emeraldine salt (ES) form composites. Stable dispersions of ES–CNT in organic media are prepared using the post doping method, inverse emulsion polymerization, or ex situ polymerizations. On the contrary, stable water dispersions of CNT/ES are prepared using hydrophilization of a preformed CNT/ES composite, direct synthesis of micelle–CNT hybrid templates, interfacial polymerization, covalent functionalization of CNT with a water soluble polymer, or using electrostatic interactions between two oppositely charged ES and CNT aqueous colloids. Moreover, the strategies for the synthesis of ternary CNT/PANI composites incorporating noble metal nanoparticles, metal oxide, or graphene sheets are also presented and analyzed in depth. Finally, we give a review of potential applications, including chemical sensors, capacitors, fuel cells and electronic devices. [Copyright &y& Elsevier]

Abstract: A novel electrochemical sensor for the selective and sensitive detection of dopamine (DA) in presence of large excess of ascorbic acid (AA) and uric acid (UA) at physiological pH was developed by the bulk modification of carbon paste electrode (CPE) with biocompatible graphite oxide (GO). Very small quantity of GO in carbon paste matrix imparted selectivity through electrostatic interactions. The modifier was characterized using infrared spectroscopy and powder X-ray diffraction. Large peak separation, good sensitivity and stability allow this modified electrode to analyze DA individually and simultaneously along with AA and UA. Applying differential pulse technique, DA could be detected even in the presence of 1000 fold excess of AA and UA. A linear dynamic range of 0.07–70μM with detection limit of 1.5×10−8 M was obtained for DA. None of the bulk modified electrodes reported in the literature have shown such a low detection limit at the physiological pH. The practical application of the modified electrode was demonstrated by spiking the human blood serum and cerebral fluid with dopamine and the results obtained were satisfactory. [Copyright &y& Elsevier]

A nano-scaled graphite oxide (GO) was prepared with a micro-layer structure for intercalation. Graphite-intercalated SnO2 was obtained at temperatures lower than 100°C. The morphology, microstructure, crystalline phases and thermal property of this intercalative composite were studied by atomic force microscopy (AFM), field-emission scanning electron microscopy (FE-SEM), X-ray diffractometry (XRD) and differential scanning calorimetry-thermogravimetry (DSC-TG) doped with a proper amount of graphite-intercalated composites (GITs), GIT-SnO2 composite was obtained after heat treatment. This combined gas sensor reveals low resistance and high sensitivity to butane between 200°C and 300°C. [ABSTRACT FROM AUTHOR]

To relieve the press of volume change of SnO 2. The collector is graphite oxide (GO), the "bridge" is Mn–C and Sn–O–Mn and aramid carbon nanotube conductive paper (AP) as a current collector to construct SnO 2 @Mn@GO/AP anode. Here, the experiment of manganese bridging SnO 2 and graphite oxide (GO) through covalent bonding are proved to obtain a stable structure. In this special structure, the manganese is able to covalently "bridge" graphite oxide (GO) and tin oxide through Mn–C and Sn–O–Mn bonding and the manganese acts as a buffer layer to uniformly encapsulate the tin oxide, that the batteries remain stable during charging and discharging. Furthermore, aramid carbon nanotube conductive paper (AP) demonstrates a rough surface, which has an excellent bearing capacity for SnO 2 than copper foil. After testing, the loading of the active substance was as high as 2.11 mg/cm2. Electrochemical tests shown that the primary discharge specific capacity of electrode reached 1768.29 mAh·g−1 at a current density of 100 mAh·g−1. After 100 cycles, the specific discharge capacity still maintained above 679.21 mAh·g−1 with a coulombic efficiency of 98.1%. • The collector is graphite oxide (GO), the "bridge" is Mn–C and Sn–O–Mn and aramid carbon nanotube conductive paper (AP) as a current collector to construct SnO 2 @Mn@GO/AP anode. • In this special structure, the manganese is able to covalently "bridge" graphite oxide (GO) and tin oxide through Mn–C and Sn–O–Mn bonding and the manganese acts as a buffer layer to uniformly encapsulate the tin oxide, that the batteries remain stable during charging and discharging. [ABSTRACT FROM AUTHOR]

A molecularly imprinted polymer (MIP) base on the surface of graphite oxide (GO) has been developed for the selective recognition of di(2-ethylhexyl)phthalate (DEHP), and applied for the extraction of DEHP in a milk bag sample, with detection by high-performance liquid chromatography. The surface-molecularly imprinted material was prepared by precipitation polymerization in N,N -dimethylformamide (DMF) solvent, using GO as the supporting material, DEHP as the template molecule, and methacrylic acid (MAA) as the functional monomer; the synthesis conditions were also optimized. The obtained GO-MAA-MIP was characterized by Fourier transform infrared (FTIR) spectroscopy and transmission electron microscopy (TEM). The adsorption properties of the product were evaluated by adsorption experiments, including adsorption isotherms, kinetics, selectivity, saturated adsorption capacity, adsorption equilibrium time, and reusability. Under optimized conditions, DEHP was effectively extracted in the real sample (milk bag) and detected by HPLC. Linearity was obtained with a correlation coefficient ( R 2 ) of 0.9979 in a linear range of 0.5-50 mg/L. The limits of detection and quantitation were 0.03 mg/L and 0.1 mg/L, respectively. The average recoveries of the spiked samples at three concentration levels of DEHP ranged from 81.6% to 92.4% with relative standard deviations (RSDs) less than 7%. The results indicated that the proposed GO-MAA-MIP-SPE (solid phase extraction) protocol with HPLC-UV detection could be applied for the selective analysis of DEHP in real samples.