Abstract We report on the design and testing of new graphite and graphene oxide‐based extended π‐conjugated synthetic scaffolds for applications in sustainable chemistry transformations. Nanoparticle‐functionalised carbonaceous catalysts for new Fischer Tropsch and Reverse GasWater Shift (RGWS) transformations were prepared: functional graphene oxides emerged from graphite powders via an adapted Hummer's method and subsequently impregnated with uniform‐sized nanoparticles. Then the resulting nanomaterials were imaged by TEM, SEM, EDX, AFM and characterised by IR, XPS and Raman spectroscopies prior to incorporation of Pd(II) promoters and further microscopic and spectroscopic analysis. Newly synthesised 2D and 3D layered nanostructures incorporating carbon‐supported iron oxide nanoparticulate pre‐catalysts were tested, upon hydrogen reduction in situ, for the conversion of CO2 to CO as well as for the selective formation of CH4 and longer chain hydrocarbons. The reduction reaction was also carried out and the catalytic species isolated and fully characterised. The catalytic activity of a graphene oxide‐supported iron oxide pre‐catalyst converted CO2 into hydrocarbons at different temperatures (305, 335, 370 and 405 °C), and its activity compared well with that of the analogues supported on graphite oxide, the 3‐dimensional material precursor to the graphene oxide. Investigation into the use of graphene oxide as a framework for catalysis showed that it has promising activity with respect to reverse gas water shift (RWGS) reaction of CO2 to CO, even at the low levels of catalyst used and under the rather mild conditions employed at atmospheric pressure. Whilst the γ‐Fe2O3 decorated graphene oxide‐based pre‐catalyst displays fairly constant activity up to 405 °C, it was found by GC‐MS analysis to be unstable with respect to decomposition at higher temperatures. The addition of palladium as a promoter increased the activity of the iron functionalised graphite oxide in the RWGS. The activity of graphene oxide supported catalysts was found to be enhanced with respect to that of iron‐functionalised graphite oxide with, or without palladium as a promoter, and comparable to that of Fe@carbon nanotube‐based systems tested under analogous conditions. These results display a significant step forward for the catalytic activity estimations for the iron functionalised and rapidly processable and scalable graphene oxide. The hereby investigated phenomena are of particular relevance for the understanding of the intimate surface morphologies and the potential role of non‐covalent interactions in the iron oxide‐graphene oxide networks, which could inform the design of nano‐materials with performance in future sustainable catalysis applications.

Design and synthesis of a novel porphyrin-based nanohybrid, whereby the entire surface of GO is modified via supramolecular assembly, is reported by S. I. Pascu and co-workers on page 687. The Zn(II)-porphyrin@GO nanohybrid forms stable dispersions in ethanol, likely containing free and bound Zn(II)-porphyrin in a dynamic exchange. New opportunities for using uniform dispersions of tailor-made nanohybrids incorporating GO within layered materials are opened up.

The surface modification of graphene oxide (GO) is carried out via the supramolecular functionalization route using a Zn(II)‐porphyrin which is soluble in common organic solvents on basis of long alkyl chains present at the exocyclic positions. This acts as a dispersing agent and decorates the surface of the graphene oxide uniformly, giving rise to a new nanohybrid denoted Zn(II)‐porphyrin@GO. The resulting Zn(II)‐porphyrin@GO nanohybrid forms a stable dispersion in ethanol (as characterized by several different spectroscopic techniques such as UV–vis, Fourier transform infrared, Raman). The morphology of Zn(II)‐porphyrin@GO nanohybrid is investigated by atomic force microscopy (AFM) and transmission electron microscope (TEM)/selected area electron diffraction. Both TEM and AFM measurements indicate that the Zn(II)‐porphyrin self‐assemble onto the surface of graphene oxide sheets. Steady‐state and time‐resolved fluorescence emission studies in the dispersed phase, and as a thin film, point toward the strongly quenched fluorescence emission and lifetime decay, suggesting that energy transfer occurs from the singlet excited state of Zn(II)‐porphyrin unit to GO sheets.

This paper presents the effects of hygrothermal aging on the durability of a pultruded flat sheet, immersed in distilled water at 25°C, 40°C, 60°C or 80°C for a period of 224days. Elevated temperatures noticeably increase the moisture diffusion coefficient and moisture uptake behaviour. Measured changes in the tensile and in-plane shear mechanical properties were examined after 28, 56, 112 or 224days. Tensile properties remained practically unaffected by aging whereas matrix dominated shear properties revealed an initial drop which was recovered to a substantial degree after further hygrothermal aging. Visco-elastic property changes due to the superimposing mechanisms of plasticization, additional cross-linking etc. were recorded. Scanning Electron Microscopy micrographs indicate that the fibre/matrix interface remained practically intact, even after the most aggressive hot/wet aging. X-ray Energy Dispersive Spectroscopy analysis showed no chemical degradation incidents on the fibre reinforcement surfaces and infrared spectroscopy revealed superficial chemical alteration in the aging matrix. Optical microscopy revealed matrix cracking in samples aged at 80°C for 112days. Lastly, Computed Tomography scans of un-aged material showed internal imperfections that undoubtedly enhanced moisture transport. After aging at 60°C for 112days, Computed Tomography detected preferentially situated water pockets.

Oil analysis for the case of quinizarin in methyllaurate is demonstrated with a disposable carbon microsphere -polystyrene composite electrode. Oxidation and reduction of quinizarin are observed as three-phase boundary processes at the immiscible oil vertical bar water vertical bar carbon interface. Randomly packed glassy carbon microspheres (2-12 mu m diameter) held together with a polystyrene binder (ca. 0.1% by weight) are immobilized onto a pencil lead electrode and used for electrochemical oil analysis. Porefilling with oil is optimised for voltammetric detection and fluorescence spectroscopy is employed to support the mechanistic analysis based on voltammetry. Future applications for a wider range of oils and additives are proposed.

This paper studies the moisture uptake characteristics of a pultruded E-glass fibre reinforced (isophthalic polyester) polymer after long-term exposure to hot/wet conditions. Both fully exposed samples of varying aspect ratios and selectively exposed samples were immersed in distilled water at 25 degrees C, 40 degrees C, 60 degrees C and 80 degrees C for a period of 224 days. For the fully exposed condition, bulk and directional diffusion coefficient values were determined. A three-dimensional approach using Fickian theory was applied to approximate the principal direction diffusions at 60 degrees C by using mass changes from samples having different aspect ratios. This revealed that the diffusion coefficient in the longitudinal (pultrusion) direction to be an order of magnitude higher than in the transverse and through-thickness principal directions. Diffusion coefficients in the three principal directions have also been determined for the selectively exposed condition at 60 degrees C through the application of one-dimensional Fickian theory. It was found that the size and shape of the samples influences moisture uptake characteristics, and thereby the values determined for bulk and directional diffusion coefficients. Furthermore, the influence of exposure temperature on moisture uptake and mass loss with time was examined. Investigation of the water medium by means of electrical measurements suggested that decomposition of the polymeric composite initiates very early, even after the very first day of immersion. Comparison between the infrared signatures from the pultruded material and the water's residual substances revealed significant decomposition, and this behaviour is verified by Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopic (EDS) analysis as well as the recorded mass loss after 224 days of aging. (C) 2015 The Authors. Published by Elsevier Ltd.

Vacuum carbonization of organic precursors usually causes considerable structural damage and collapse of morphological features. However, for a polymer with intrinsic microporosity (PIM-EA-TB with a Brunauer-Emmet-Teller (BET) surface area of 1027 m(2)g(-1)), it is shown here that the rigidity of the molecular backbone is retained even during 500 °C vacuum carbonization, yielding a novel type of microporous heterocarbon (either as powder or as thin film membrane) with properties between those of a conducting polymer and those of a carbon. After carbonization, the scanning electron microscopy (SEM) morphology and the small-angle X-ray scattering (SAXS) Guinier radius remain largely unchanged as does the cumulative pore volume. However, the BET surface area is decreased to 242 m(2)g(-1), but microporosity is considerably increased. The new material is shown to exhibit noticeable electrochemical features including two pH-dependent capacitance domains switching from ca. 33 Fg(-1) (when oxidized) to ca. 147 Fg(-1) (when reduced), a low electron transfer reactivity toward oxygen and hydrogen peroxide, and a four-point-probe resistivity (dry) of approximately 40 MΩ/square for a 1-2 μm thick film.

Cotton-extracted cellulose nanocrystals are spin-coated from aqueous suspension (0.6wt%) onto glass slides to give ca. 40nm thick films. Impregnation with LiCl and redox active Fe(CN)63−/4− into this film gives extremely thin redox active layers (typically 170nm at 60% relative humidity), which were investigated with a 4-point or 3-point probe electrochemical system based on 250μm diameter platinum wire probes. Both voltammetry and impedance measurements were performed and effects from humidity, concentrations, and time domain on measurements are reported. Only a pico-litre volume under the working electrode was “active” to give a novel electroanalytical “spot test”.

This paper studies the moisture uptake characteristics of a pultruded E-glass fibre reinforced (isophthalic polyester) polymer after long-term exposure to hot/wet conditions. Both fully exposed samples of varying aspect ratios and selectively exposed samples were immersed in distilled water at 25 C, 40 C, 60 C and 80 C for a period of 224 days. For the fully exposed condition, bulk and directional diffusion coefficient values were determined. A three-dimensional approach using Fickian theory was applied to approximate the principal direction diffusions at 60 C by using mass changes from samples having different aspect ratios. This revealed that the diffusion coefficient in the longitudinal (pultrusion) direction to be an order of magnitude higher than in the transverse and through-thickness principal directions. Diffusion coefficients in the three principal directions have also been determined for the selectively exposed condition at 60 C through the application of one-dimensional Fickian theory. It was found that the size and shape of the samples influences moisture uptake characteristics, and thereby the values determined for bulk and directional diffusion coefficients. Furthermore, the influence of exposure temperature on moisture uptake and mass loss with time was examined. Investigation of the water medium by means of electrical measurements suggested that decomposition of the polymeric composite initiates very early, even after the very first day of immersion. Comparison between the infrared signatures from the pultruded material and the water's residual substances revealed significant decomposition, and this behaviour is verified by Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopic (EDS) analysis as well as the recorded mass loss after 224 days of aging. © 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Functionalized carbon nanoparticles (or blacks) have promise as novel active high-surface-area electrode materials, as conduits for electrons to enzymes or connections through lipid films, or as nano-building blocks in electroanalysis. With previous applications of bare nanoblacks and composites mainly in electrochemical charge storage and as substrates in fuel cell devices, the full range of benefits of bare and functionalized carbon nanoparticles in assemblies and composite (bio)electrodes is still emerging. Carbon nanoparticles are readily surface-modified, functionalized, embedded, or assembled into nanostructures, employed in bioelectrochemical systems, and incorporated into novel electrochemical sensing devices. This focus review summarizes aspects of a rapidly growing field and some of the recent developments in carbon nanoparticle functionalization with potential applications in (bio)electrochemical, photoelectrochemical, and electroanalytical processes.

It makes sense: The front cover artwork represents anion transfer of highly hydrophilic phosphate and hydroxide anions into a water-immiscible organic phase, which is driven with a manganese(II/III) redox system and facilitated with a hydrophobic oil-based boronic acid. (DOI: 10.1002/celc.201402181).

Raman spectra have been collected using three excitation wavelengths for thirteen uranyl mineral samples, including novác̆ekite, and analysed.

Commercial nano-CIGSe powder (nominal CuIn0.7Ga0.3Se2, average particle size < 100 nm) is applied to tin-doped indium oxide (ITO) electrodes in a simple "roll-on" process from n-hexanol to give thin photoelectrochemically active films. Films "as deposited" and "annealed" in selenium atmosphere at 350 degrees C are compared with the latter performing substantially better. Perhaps surprisingly, photo-transient voltammetry suggests only insignificant effects when changing aqueous electrolyte from Eu(NO3)(3) to KNO3 or when changing electrolyte concentration, most likely due to a dominating electron-quenching process caused by dissolved dioxygen. However, when under inert argon atmosphere, generator-collector phototransient voltammetry with a 50 mu m Pt collector microelectrode placed close to the CIGSe film surface proves photo-induced H-2 formation in 0.1 M KNO3 or in 0.1 M HNO3 (and it confirms electron-quenching by O-2 in the presence of air). In aqueous 0.1 M HNO3 effective electron-quenching (photo-hydrogenation) with fumaric acid is observed with current yields of ca. 60% for fumarate to succinate conversion. Detrimental loss of photoelectrochemical activity (probably via photo-corrosion) with time occurs. (C) 2013 Elsevier B.V. All rights reserved.

A novel two-photon-fluorescent N,O-heteroatom-rich carbon nanomaterial has been synthesized and characterized. The new carbon nanoparticles were produced by hydrothermal conversion from a one-photon-fluorescent poly(4-vinylpyridine) precursor (P4VP). The carbonized particles (cP4VP dots) with nonuniform particle diameter (ranging from sub-6 to 20 nm with some aggregates up to 200 nm) exhibit strong fluorescence properties in different solvents and have also been investigated for applications in cell culture media. The cP4VP dots retain their intrinsic fluorescence in a cellular environment and exhibit an average excited-state lifetime of 2.0 ± 0.9 ns in the cell. The cP4VP dots enter HeLa cells and do not cause significant damage to outer cell membranes. They provide one-photon or two-photon fluorescent synthetic scaffolds for imaging applications and/or drug delivery.

Low temperature carbonisation (500 degrees C) of poly-acrylonitrile nanofibres (typically 100 nm diameter) electrospun into a nanoweb-like deposit on tin-doped indium oxide (ITO) substrates (or as free-standing membrane over glass capillaries) yields active carbon film electrodes but with only relatively low electrochemical activity. Without resorting to higher carbonisation temperatures, substantial improvements in both electrical conductivity and electron transfer reactivity are observed after "surface-graphenisation", that is coating with graphene-oxide prior to vacuum carbonisation. Improvements in voltammetric characteristics are demonstrated for both membranes mounted on ITO substrates and free-standing membranes suspended over the end of a borosilicate glass capillaries for (i) the aqueous phase hydroquinone/benzoquinone redox system and (ii) the biphasic oil jaqueous ion transfer redox system tetraphenylpor-phyrinato-Mn(III/II) in 4-phenyl-(3-propyl)-pyridine).

A one-step method of preparing photoelectrochemically active nanostructured BiVO4 films is reported based on thermolysis (500 °C in air) of a polyethylene glycol (PEG300) “paint-on” precursor solution containing Bi3+ (as nitrate) and VO4 3− (as the metavanadate ammonium salt). Films are formed directly on tin-doped indium oxide (ITO) substrates and characterised by electron microscopy (scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS)), X-ray diffraction, Raman spectroscopy, and photoelectrochemistry. The nanocrystalline film exhibited typically up to 52 % incident photon to current efficiency (IPCE) at 1.0 V vs. saturated calomel electrode (SCE) in aqueous 0.5 M Na2SO4 with oxalate, strongly enhancing photocurrents.

Hydrous iron oxide materials with a predefined shape, photo-electrochemical activity, low density (estimated to be 0.32 g cm(-3)), and high fractal porosity (BET ca. 117 m(2) g(-1)) are formed via internal hydrolytic transformation of the crystalline metal-organic framework MIL-53(Fe) in dilute aqueous hydroxide.

Anion transfer for highly hydrophilic phosphate and hydroxide anions into a water-immiscible organic phase, 3-(4-phenylpropyl)-pyridine (or PPP), is driven with the tetraphenylporphyrinato manganese(II/III) (or TPPMn) redox system and facilitated with a hydrophobic oil-based boronic acid ((3-(1,3-dioxo-6-propylamino-1H-benzo[de]isoquinolin-2(3H)-yl)phenyl)boronic acid). Both 1)experiments with random arrays of microdroplets (transient) and 2)experiments in a gold-gold dual-plate oil-filled microtrench generator-collector configuration (approaching steady state), show that phosphate transfer is facilitated by boronic acid. At pH7.5 a switch in mechanism occurs from phosphate transfer to hydroxide transfer. Accelerated charge transport is observed lateral to the oil|water interface. Improved boronic acid facilitators and nanotrench electrodes are discussed in terms of future feasibility for phosphate sensing applications.

Coating using magnetically enhanced plasma deposition gives smooth diamond-like carbon films that increase hardness and wear resistance of nanostructures.

Single crystals of Cu2ZnSnS4 have been produced within sealed quartz ampoules via the chemical vapour transport technique using I2 as the transporting agent. The effects of temperature gradient and I2 load on the crystal habit and composition are considered. Crystals have been analyzed with XRD, SEM, and TEM for compositional and structural uniformities at both microscopic and nanoscopic levels. The synthesized crystals have suitable (I2-load dependent) properties and are useful for further solar absorber structural and physical characterizations. A new chemical vapour transport method based on longitudinally isothermal treatments is attempted. Based on a proposed simplistic mechanism of crystal growth, conditions for crystal enlargement with the new method are envisaged.