Microwave Exfoliation of Graphite Oxides in HS Plasma for the Synthesis of Sulfur-Doped Graphenes as Oxygen Reduction Catalysts.

Tuning the electronic and chemical properties of graphene can be carried out through heteroatomic doping, enabling its use as an electrocatalyst. Sulfur-doped graphene has been suggested to be a viable alternative to traditional Pt-based catalysts for oxygen reduction under alkaline conditions. Herein we present a fast and efficient route to synthesize S-doped graphenes through the microwave-assisted exfoliation and reduction of three different graphite oxides in the presence of hydrogen sulfide.

Graphene and its electrochemistry - an update.

The electrochemistry of graphene and its derivatives has been extensively researched in recent years. In the aspect of graphene preparation methods, the efficiencies of the top-down electrochemical exfoliation of graphite, the electrochemical reduction of graphene oxide and the electrochemical delamination of CVD grown graphene, are currently on par with conventional procedures. Electrochemical analysis of graphene oxide has revealed an unexpected inherent redox activity with, in some cases, an astonishing chemical reversibility.

Geographical and geological origin of natural graphite heavily influence the electrical and electrochemical properties of chemically modified graphenes.

Natural graphite is an important precursor for the production of chemically modified graphenes in bulk quantities for electrochemical applications. These natural graphites have varying fundamental properties due to the different geological processes and environments at their points of origin, which are expected to affect their chemical reactivity and hence the properties of the derived graphene materials. Four different natural graphites with known geographical and geological origins were exposed to a modified Hummers oxidation method and the resulting graphite oxides were studied.

Synthetic routes contaminate graphene materials with a whole spectrum of unanticipated metallic elements.

The synthesis of graphene materials is typically carried out by oxidizing graphite to graphite oxide followed by a reduction process. Numerous methods exist for both the oxidation and reduction steps, which causes unpredictable contamination from metallic impurities into the final material. These impurities are known to have considerable impact on the properties of graphene materials.

Graphane and hydrogenated graphene.

Graphane, the fully hydrogenated analogue of graphene, and its partially hydrogenated counterparts are attracting increasing attention. We review here its structure and predicted material properties, as well as the current methods of preparation. Graphane and hydrogenated graphenes are far more complex materials than graphene, expected to have a tuneable band gap via the extent of hydrogenation, as well as exhibit ferromagnetism.

Unscrolling of multi-walled carbon nanotubes: towards micrometre-scale graphene oxide sheets.

Chemical routes toward obtaining graphene materials are commonly used in the field, and one such preparation method is the unzipping of carbon nanotubes into long, thin graphene nanoribbons. In this work, we show that oxidative permanganate treatment of Scroll type multi-walled carbon nanotubes can lead to large, stacked sheets instead of nanoribbons. This difference is suggested to arise from the type of nanotube used, such as the Russian Doll form or Scroll form causing a change in the initial oxidation site location and ultimately leading to an alternate nanotube opening process.

Thermally reduced graphenes exhibiting a close relationship to amorphous carbon.

Graphene is an important material for sensing and energy storage applications. Since the vast majority of sensing and energy storage chemical and electrochemical systems require bulk quantities of graphene, thermally reduced graphene oxide (TRGO) is commonly employed instead of pristine graphene. The sp(2) planar structure of TRGO is heavily damaged, consisting of a very short sp(2) crystallite size of nanometre length and with areas of sp(3) hybridized carbon.

Synthesis and application of a recyclable ionic liquid-supported imidazolidinone catalyst in enantioselective 1,3-dipolar cycloaddition.

The synthesis of recyclable ionic liquid-supported imidazolidinone catalyst I and its application in 1,3-dipolar cycloaddition of nitrone with α,β-unsaturated aldehyde with high performance were described. Most importantly, the catalyst I can be recovered and recycled for up to five runs without observing significant decrease in catalytic activity.

Direct synthesis of ester-containing indium homoenolate and its application in palladium-catalyzed cross-coupling with aryl halide.

An efficient method for the synthesis of ester-containing indium homoenolate via a direct insertion of indium into β-halo ester in the presence of CuI/LiCl was described. The synthetic utility of the indium homoenolate was demonstrated by palladium-catalyzed cross-coupling with aryl halides in DMA with wide functional group compatibility.

Palladium-catalyzed cross-coupling of indium homoenolate with aryl halide with wide functional group compatibility.

An efficient palladium-catalyzed cross-coupling of indium homoenolate with aryl halide is described. The reactions proceeded efficiently in DMA at 100 °C to afford the desired products of β-aryl ketones in moderate to good yields. Various important functional groups including COR, COOR, CHO, CN, OH, and NO(2) can be well tolerated in the protocol.

Synthesis of water-tolerant indium homoenolate in aqueous media and its application in the synthesis of 1,4-dicarbonyl compounds via palladium-catalyzed coupling with acid chloride.

The first water-tolerant, ketone-type indium homoenolate was synthesized via the oxidative addition of In/InCl(3) to enones. The reaction proceeds exclusively in aqueous media. Both indium and indium(III) chloride are necessary for the smooth conversion of the reaction.