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Carbon Powder (carbon + powder)
Selected AbstractsCarbon Powder Based Films on Traditional Solid Electrodes as an Alternative to Disposable ElectrodesELECTROANALYSIS, Issue 11 2006Bogdan Yosypchuk Abstract The covering of conventional solid electrode with a film using an ink containing a conductive powder and a polymer enables to broaden the potential window of the original solid electrode. A solid silver amalgam electrode covered with such a film exhibits a potential window from ,600,mV to +1400,mV vs. SCE reference electrode. The renewal of the film is fast and simple: the electrode can be simply wiped with a filter paper to remove the old film and immersed into an ink solution or 1,2,,L of this ink solution can be applied to the surface of the electrode with a micro dispenser to form a new film. Therefore, just the inexpensive film at the electrode surface is disposable and there is no need to dispose the whole, more expensive electrode. Moreover, when a suitable electrochemical pretreatment of the film electrode is applied, the same film can be used for reproducible measurements for several days. [source] Tapered Carbon Nanotubes from Activated Carbon Powders,ADVANCED MATERIALS, Issue 2 2006Q. Hu Tapered carbon nanotubes (TCNTs) are produced from activated carbon powders via simple thermal catalytic reactions in which the carbon nanotubes grow though a Sn-catalyzed vapor,liquid,solid growth process. The tapered nanotubes are well aligned and have a length of several tens of micrometers (see Figure). [source] Copper Oxide , Graphite Composite Electrodes: Application to Nitrite SensingELECTROANALYSIS, Issue 1 2007Biljana, ljuki Abstract A simple method for the modification of carbon powder with copper oxides is presented. Carbon powder is impregnated with copper(II) nitrate by stirring carbon powder in copper(II) nitrate solution for 1 hour and subsequently thermally treated at 823,K. The modified carbon powder was characterized using electrochemical and spectroscopic techniques. The existence of both copper(I) and copper(II) oxides have been established. The copper oxide modified carbon powder was used for preparation of composite electrodes, and the electrochemical and electrocatalytic behavior of the resulting composite electrodes was studied. The copper oxide modified carbon powder , epoxy composite electrodes showed a high electrocatalytic activity for the nitrite detection in aqueous media, with the detection limit comparable or lower than detection limits obtained with other electrochemical sensors. [source] Electroreduction of Oxygen and Electrooxidation of Methanol at Carbon and Single Wall Carbon Nanotube Supported Platinum ElectrodesELECTROANALYSIS, Issue 10 2008Ahmad, Nozad Golikand Abstract The present research aimed at investigating the electrocatalytic properties and the electrochemical deposition of Pt nanoparticles on carbon powder, carbon nanotube and preparation of carbon and single wall carbon nanotube supported platinum electrodes. The Pt nanoparticles were synthesized by electroreduction of hexachloroplatinic acid in aqueous solution at ,200,mV. Electrocatalytic properties of the modified electrodes for oxygen reduction were investigated by cyclic voltammetry in O2 saturated solution containing 0.1,M HClO4. Methanol electrooxidation at the modified surfaces in 0.5,M HCLO4 was studied by cyclic voltammetry. The corresponding results showed that the Pt/SWCNT/GC electrode exhibits more improved catalytical activity than the Pt/C/GC electrode. [source] Copper Oxide , Graphite Composite Electrodes: Application to Nitrite SensingELECTROANALYSIS, Issue 1 2007Biljana, ljuki Abstract A simple method for the modification of carbon powder with copper oxides is presented. Carbon powder is impregnated with copper(II) nitrate by stirring carbon powder in copper(II) nitrate solution for 1 hour and subsequently thermally treated at 823,K. The modified carbon powder was characterized using electrochemical and spectroscopic techniques. The existence of both copper(I) and copper(II) oxides have been established. The copper oxide modified carbon powder was used for preparation of composite electrodes, and the electrochemical and electrocatalytic behavior of the resulting composite electrodes was studied. The copper oxide modified carbon powder , epoxy composite electrodes showed a high electrocatalytic activity for the nitrite detection in aqueous media, with the detection limit comparable or lower than detection limits obtained with other electrochemical sensors. [source] Effect of Activated Carbon Bed on Binder Removal from Ceramic Injection MoldingsJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 3 2001Martin Trunec Weight losses during the binder removal from ceramic injection moldings that have been placed in beds of activated carbon powder and two types of alumina powder were compared. The effect of the specimen size and shape on debinding in a bed of activated carbon was investigated. Because of the structure of its particles, activated carbon powder allowed binder losses in ceramic moldings that consisted of submicrometer-sized particles to increase at a temperature of 130°C. The binder loss in a bed of activated carbon was dependent on the ratio of surface area to volume of the body that was extracted. Renewal of the sorption abilities of the bed of activated carbon after saturation with binder increased the rate of binder removal. [source] Chemical Derivatisation of Multiwalled Carbon Nanotubes Using Diazonium Salts,CHEMPHYSCHEM, Issue 11 2004Charles G. R. Heald A facile and versatile modification strategy: A chemically activated method of covalently derivatising carbon powder, via the chemical reduction of aryl diazonium salts with hypophosphorous acid, to include the covalent derivatisation of multiwalled carbon nanotubes (MWCNTs) is demonstrated. The specific molecular environments of 1-anthraquinonyl moieties attached to MWCNTs (see picture) produce interesting effects. [source] Tapered Carbon Nanotubes from Activated Carbon Powders,ADVANCED MATERIALS, Issue 2 2006Q. Hu Tapered carbon nanotubes (TCNTs) are produced from activated carbon powders via simple thermal catalytic reactions in which the carbon nanotubes grow though a Sn-catalyzed vapor,liquid,solid growth process. The tapered nanotubes are well aligned and have a length of several tens of micrometers (see Figure). [source] Hollow Alumina Microsphere Chain NetworksJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 1 2009Weiyou Yang Hollow Al2O3 microsphere chain networks have been synthesized via a simple two-staged pyrolysis of a precursor using active carbon powders as the template. The obtained networks are characterized using scanning electron microscopy, X-ray diffraction, and transmission electron microscopy. The chain networks are formed by subsequent aggregation of the prior formed hollow Al2O3 microspheres. The obtained chain networks are promising for the applications in catalyst support, filtration, and other applications due to their lightweight and highly porous nature. [source] A New Ternary Nanolaminate Carbide: Ti3SnC2JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 8 2007Sylvain Dubois We report on the synthesis of Tin+1SnCn (MAX phases) by hot isostatic pressing starting with titanium, tin, and carbon powders. In addition to the already known Ti2SnC compound (211 MAX phase), a new 312 MAX phase, Ti3SnC2, is formed. Its lattice parameters, deduced from Rietveld analysis of X-ray diffraction patterns, are found to be a=0.31366 nm and c=1.8650 nm. [source] Synthesis of ultrafine titanium carbonitride powders,APPLIED ORGANOMETALLIC CHEMISTRY, Issue 5 2001Frederic Monteverde Abstract Titanium-carbonitride-based materials are very hard materials with increasing technical importance. They are mainly used in composites with various metal carbides and/or metallic binders (cermets) for metal cutting operations. These applications call for the synthesis of titanium carbonitride powders with homogeneous chemical composition, as small as possible grain size and narrower grain size distribution. Nowadays on the market, only commercial submicrometric (0.5,2,,m) powders are available. Starting from blends of nanosize commercial TiN or TiO2 powders mixed with different carbon powders (carbon black, active carbon), this study aimed to set up a low-cost process to synthesize fine and pure TiC1,X,NX powders with an X value close to 0.5. The morphology of the as-obtained powders and the progress of the reaction were investigated by scanning electron microscopy and X-ray diffraction. The stoichiometric parameter X was estimated on the basis of a TiC1,X,NX Raoultian solid solution together with Vegard's rule. The results are presented and discussed to assess relations between powder characteristics and processing conditions. The most encouraging results were obtained using a mixture TiN,+,10,wt%C (carbon black) processed at 1430,°C for 3,h under flowing argon. Regularly shaped particles with limited agglomeration ranged from 100 to 300,nm and an X value close to 0.5 Copyright © 2001 John Wiley & Sons, Ltd. [source] | |||||||||||||