Other Carbon Layered Materials

Trametes versicolor laccase Graphite Biosensors for phenolic compounds [81] 

Trametes hirsuta laccase Graphite Electrode for direct electrocatalytic reduction of 02 to H20 [82] 

Glucose oxidase Modified graphite Amperometric glucose biosensor [85] 

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Given the high oxidation rates of silicon-terminated multilayer films, other capping layer materials have been studied extensively. Oxidation can be appreciably reduced with protective capping layers. Extended lifetimes have been reported for ruthenium (Ru)-capped and carbon-capped ML mirrors. Ruthenium... 

The discovery that C6o (buckminsterfullerene) self-assembles from a condensing chaotic plasma causes us to look back and recognize certain misconceptions that existed over the structure of graphite and other similarly layered materials. The discovery has not only fundamentally changed our understanding of synthetic carbon chemistry, but has also opened up whole new and exciting possibilities in materials science - in particular at nanoscale dimensions. Furthermore, this new perspective also rationalizes numerous properties of bulk graphite that have hitherto been known but unexplained. 

Various other classes of catalysts have been investigated for NH3-SCR, in particular, metal-containing clays and layered materials [43 15] supported on active carbon [46] and micro- and meso-porous materials [31b,47,48], the latter also especially investigated for HC-SCR [25,3lb,48-53], However, while for NH3-SCR, either for stationary or mobile applications, the performances under practical conditions of alternative catalysts to V-W-oxides supported on titania do not justify their commercial use if not for special cases, the identification of a suitable catalyst, or combination of catalysts, for HC-SCR is still a matter of question. In general terms, supported noble metals are preferable for their low-temperature activity, centred typically 200°C. As commented before, low-temperature activity is a critical issue. However, supported noble metals have a quite limited temperature window of operation. 

Field emission displays are VFDs that use field emission cathodes as the electron source. The cathodes can be molybdenum microtips,33-35 carbon films,36,37 carbon nanotubes,38" 16 diamond tips,47 or other nanoscale-emitting materials.48 Niobium silicide applied as a protective layer on silicon tip field emission arrays has been claimed to improve the emission efficiency and stability.49 ZnO Zn is used in monochrome field emission device (FED) displays but its disadvantage is that it saturates at over 200 V.29... 

A typical lithium-ion cell consists of a positive electrode composed of a thin layer of powdered metal oxide (e.g., LiCo02) mounted on aluminum foil and a negative electrode formed from a thin layer of powdered graphite, or certain other carbons, mounted on a copper foil. The two electrodes are separated by a porous plastic film soaked typically in LiPFe dissolved in a mixture of organic solvents such as ethylene carbonate (EC), ethyl methyl carbonate (EMC), or diethyl carbonate (DEC). In the charge/ discharge process, lithium ions are inserted or extracted from the interstitial space between atomic layers within the active materials. 

The presence of the potassium atoms causes the distance between the layers of carbon atoms to increase from the value of 235 pm in graphite to 540 pm in C8K. When rubidium and cesium atoms are placed between the layers, the distances between the carbon layers are 561 and 595 pm, respectively. As would be expected for materials that contain atoms of an alkali metal, these materials are extremely reactive in air, and they react explosively with water. A large number of other intercalation compounds have been prepared that have halogens, interhalogens, or metal halides as the included substances. 

It has been known since the middle of the nineteenth century that atoms or molecules can be introduced between the carbon layers in graphite, and more recently it has been recognised that many other lamellar crystalline materials will behave in the same way. This phenomenon of "intercalation" results in modification of many of the properties of the basic crystalline material. In particular it leads to an expansion of the inter-lamellar gap, but the effect on inter-lamellar shear resistance will also depend on any effects on bonding which may arise. 

Since the discovery of the carbon nanotubes, there has been considerable work on other layered materials such as M0S2, WS2 and BN to explore the formation of nanotubes of these materials. Indeed several of them have been synthesized and characterized [21-23]. Similarly, nanowires of various inorganic materials have also been made [21]. In this chapter, we shall present the various important aspects of carbon nanotubes including their preparation, structure, mechanism of formation, chemical substitution, properties and applications. The methodologies developed for synthesizing nanowires and nanotubes of various inorganic materials as well as their salient features will also be discussed [21-24]. 

Research on other types of materials for H2 separation has been motivated by relatively high cost of Pd and possible membrane degradation by acidic gases and carbon as summarized in Tsuru et al.76 These authors examined microporous silica membranes together with an Ni catalyst layer for SMR reaction. However, this type of membrane allows the permeation of hydrogen as well as other gases in reactants and products, which markedly reduces hydrogen selectivity and limits methane... 

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