Carbon Nanotubes Generated from Polyphenyl Acetylene

The carbonization of polyphenyl acetylene in alumina matrix yields uniform, cylindrical, monodisperse carbon nanotubes with outer diameter almost equal to pore diameter of the alumina membrane used. The electrochemical characteristics reveal that the charge transfer at the composite electrode based on carbon nanotube might be higher compared to that of planar graphite, glassy carbon and composite electrode based on commercially available Vulcan XC72R carbon. Pt-Ru nanoparticles are highly dispersed inside the tube with an average particle size of 1.7 nm as revealed by HR-TEM images

Organic dyes containing coplanar dihexyl-substituted dithienosilole groups for efficient dye-sensitised solar cells

peer-reviewedA chromophore containing a coplanar dihexyl-substituted dithienosilole (CL1) synthesised for use in dye-sensitised solar cells displayed an energy conversion efficiency of 6.90% under AM 1.5 sunlight irradiation. The new sensitiser showed a similar fill factor and open-circuit voltage when compared with N719. Impedance measurements showed that, in the dark, the charge-transfer resistance of a cell using CL1 in the intermediate-frequency region was higher compared to N719 (69.8 versus 41.3 Omega). Under illumination at AM 1.5G-simulated conditions, the charge-transfer resistances were comparable, indicative of similar recombination rates by the oxidised form of the redox couple. The dye showed instability in ethanol solution, but excellent stability when attached to TiO2. Classical molecular dynamics indicated that interactions between ethanol and the dye are likely to reduce the stability of CL1 in solution form. Time-dependent density functional theory studies were performed to ascertain the absorption spectrum of the dye and assess the contribution of various transitions to optical excitation, which showed good agreement with experimental results.PUBLISHEDpeer-reviewe

Photocatalyst for use in the production of hydrogen from water or aqueous solutions of organic compounds

The photocatalyst for the use in the production of hydrogen from water or aqueous solutions of organic compounds by using light energy, comprises carbon, in addition to a semiconducting photocatalytic material. The photocatalytic apparatus for the production of hydrogen from water or aqueous solutions of organic compounds by using light energy, comprises a light source, a reactor transparent for the light of the light source (2), an inlet (4) for feeding water or aqueous solution to the reactor, a gas product outlet (6), and includes a photocatalyst containing carbon, in addition to a semiconducting photocatalytic material as a photocatalyst in the reactor. <IMAGE

Photocatalytic film of iron oxide, electrode with such a photocatalytic film, method of producing such films, photoelectrochemical cell with the electrode and photoelectrochemical system with the cell, for the cleavage of water into hydrogen and oxygen

The Photocatalytic film of semiconducting iron oxide (Fe2O3), contains an n-dopant, or a mixture of n-dopants, or a p-dopant or a mixture of p-dopants. Electrode consists of a substrate, with one ore more films or photocatalytic arrangements of film of semiconducting n-doped or p-doped iron oxide (Fe2O3) e.g. on the surface of one side of the substrate or on the surface of different sides. The photoelectrochemical cell comprises electrodes with a film or with films of the n-doped or p-doped semiconducting iron oxide (Fe2O3). The semiconducting iron oxide (Fe2O3) film can be manufactured with a spray pyrolysis process or a sol gel process. The system for the direct cleavage of water with visible light, into hydrogen and oxygen the system comprises one or more of the photoelectrochemical cells with photocatalytic films. The system can be a tandem cell system, comprising the photoelectrochemical cell with the doped iron oxide (Fe2O3) film. <IMAGE

Laboratory techniques for evaluating solid oxide fuel cells

The construction of a small solid oxide fuel cell laboratory is described in terms of required materials, measuring techniques and equipment design. Details of various electrode deposition techniques and ways of making contacts to the electrodes are also outlined

Catalysis in Solid-State Ionics

With the solid oxide-fuel cell, a technology exploiting ionic conductivity in electroceramic materials, small-scale co-generation plants for combined production of heat and electricity can achieve clean high-efficiency operation. However, with thermal activation of the cell chemistry, extremely high operating temperatures, about 1000°, are required, conditions incompatible with long term reliability using conventional structural materials. Lower-temperature operation depends decisively on the application of electrocatalysis at interfaces to the ceramic electrolyte

Photocatalytic degradation of Remazol Brilliant Blue (R) by sol-gel derived carbon-doped TiO2

A simple, cheap and reproducible method to produce a C-doped TiO2 photocatalyst is presented, which can harvest visible light. This doped catalyst is able to degrade a stable organic dye molecule, Remazol Brilliant Blue (R) (RBB), under sunlight and visible light alone and its activity is compared to P25. XPS analysis clearly showed that carbon was introduced into the TiO2 lattice but at much lower doping levels than initially added during the synthesis. BET and diffuse reflectance spectroscopy indicated that the doped catalysts had larger surface area and improved light absorption in the visible region than P25. However, under full sunlight this did not translate into improved photocatalytic activity when compared to P25. Even though the UV cut-off sunlight spectrum permitted P25 to discolor RBB, no actual dye mineralization was observed by total organic carbon (TOC) analysis. In contrast, the doped catalyst did not only achieve discoloration of RBB but also removed 70% of organic carbon. This gives the doped catalyst a clear advantage to operate with visible light alone, which can be produced in a much more economical way, and may therefore reduce treatment costs of wastewater from textile and other industries using dyes. Among several reactive dyes, RBB was particularly found to be the most recalcitrant to discoloration with TiO2 and this study opens a way to address this issue. The photocatalytic mechanism is discussed. (C) 2013 Elsevier B.V. All rights reserved