Carbon-doped oxide

Figure 4.33. Cross-section TEM image of the placement of a carbon-doped oxide (CDO) dielectric between metal interconnects. Reproduced with permission from Intel Corporation (http //www.intel.com).

State-of-the-art thin film Li" cells comprise carbon-based anodes (non-graphitic or graphite), solid polymer electrolytes (such as those formed by solvent-free membranes, for example, polyethylene oxide, PEO, and a lithium salt like LiPFe or LiCFsSOs), and metal oxide based cathodes, in particular mixed or doped oxides... 

Fig. 33. Reaction yield as a function of time for carbon monoxide oxidation at room temperature on pure and doped nickel oxides. NiO (200), A NiO(Li) (250), O NiO (250) X NiO(Ga) (250). Reprinted from (8) with permission. Copyright 1969 by Academic Press, Inc., New York.

For the electrochemical capacitors of Carbon-Ni Oxide system with aqueous KOH solution it is expedient to use carbonaceous graphite materials with expanded structure and modified surface. The best results were achieved with carbon surface doped with Boron, which makes this carbon superior than other conductive additives used in this study, due to its... 

In the case of oxide catalysts or alkali metal-doped oxide catalysts, basic surface sites can be generated by decarboxylation of a surface metal carbonate exchange of hydroxyl hydrogen ions by electropositive cations thermal dehydroxylation of the catalyst surface condensation of alkali metal particles on the surface and reaction of an alkali metal with an anion vacancy (AV) to give centers (e.g., Na + AV — Na + e ). 

A photoanode comprised of flame oxidized carbon doped n-Ti02 films have been reported to perform water splitting with high photoconversion efficiencies [65]. While chemically modified n-Ti02 can be prepared by the controlled combustion of Ti metal in a natural gas flame the authors, in investigating this technique [66], have found reproducibility to be a challenge. Various authors [67,68,69] have discussed in considerable depth issues surrounding the stated photoconversion efficiencies of [65]. 

Hsu, S. W., Yang, T. S., Chen, T. K. and Wong, M. S. (2007). Ion-assisted electron-beam evaporation of carbon-doped titanium oxide films as visible-light photocatalyst. Thin Solid Films 515(7-8), 3521-3526. 

Carbon-Doped Anatase Ti02 Powders as a Visible-Light Sensitive Photocatalyst Oxidative annealing of TiC used to afford yellow doped powders. Study focus as in Entry 5. 310... 

Spectral Photoresponses of Carbon-Doped Ti02 Film Electrodes. Raman spectra used to identify disordered carbon in the flame-formed samples in addition to lower nonstoichiometric titanium oxides identified by X-ray diffraction. 314... 

As seen earlier, the steps used to purify iron involves carbonaceous material to remove the oxide-based impurities, through exothermic formation of CO and CO2. Hence, carbon will be pervasive in a variety of concentrations throughout all phases of iron and steels, present as an interstitial dopant within these lattices. Experimental evidence shows that carbon-doped iron polymorphs are indeed interstitial solid solutions. For instance, the carbon atoms in bcc ferrite are located only on empty face-centered positions. However, very few of these positions are occupied throughout the lattice, as the maximum solubility of carbon in a-Fe is only between 0.01 and 0.02 wt%. From a metallic-bonding standpoint, the addition of carbon in the lattice acts as an electron sink, that is able to accept some of the delocalized electron... 

Chemisorption of carbon dioxide on doped oxides prepared at 250° was also studied calorimetrically. Initial heats of adsorption on NiO(10 Li)(250°) (27 kcal/mole) and on Ni0(10 Ga)(250°) (28 kcal/mole) are similar. The gallium-doped oxide chemisorbs at room temperature the same quantity of carbon dioxide (9.3 cm /gm) as NiO(250°) (9.7 cm3/gm), whereas the quantity of gas adsorbed on Ni0(10 Li)(250°) is larger (13.0 cm /gm). Lithia chemisorbs carbon dioxide at room temperature. However, the difference between the quantities of gas adsorbed on pure and lithiated oxides is not explained by the presence of lithia, as a separate phase, in the doped sample. It seems, therefore, that carbon dioxide, as oxygen, is chemisorbed at room temperature on anionic vacancies whose concentration is particularly large on lithiated oxides. 

Fia. 31. Reaction yield as a function of time for carbon monoxide oxidation at room temperature on pure and doped nickel oxides. 

The reaction order with respect to time was determined by the differential method. A fractional order (1.3) is obtained for the catalytic reaction on both doped samples. However, as in the case of the same reaction on pure oxides, the initial reaction rate does not depend upon the pressure of either reagent (order zero). Since these results are similar to those obtained on pure samples, NiO(200°) and NiO(250°), we believe that the order with respect to time is, as in the former case, apparent and that it results from the inhibition of surface sites by carbon dioxide, the reaction product. The slowest step of the reaction mechanism on doped oxides should occur, therefore, between adsorbed species. 

A Basicity of Alkali Metal Ion-doped Oxides.- In order to increase a surface basicity, different species with donor properties may be deposited. The majority of these are the alkali metal salts or salts of the alkaline earth metals. The deposition of hydroxides carbonates, nitrates, oxalates and other organic salts of L,i, Na, K, Rb, Cs, Mg, Ca, Sr, Ba on different supports has been known for years. They are said to increase the basic properties of the surface. The mechanism of the creation of these new basic centres is not clear, because the acid-base properties of a support, on which the salt has been introduced, do not change monotonically with the quantity of introduced metal ions. It is possible, that the interaction of surface groups with the metal ions leads to several reactions,... 

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