Boron-doped

Zinc—bromine storage batteries (qv) are under development as load-leveling devices in electric utilities (64). Photovoltaic batteries have been made of selenium or boron doped with bromine. Graphite fibers and certain polymers can be made electrically conductive by being doped with bromine. Bromine is used in quartz—haUde light bulbs. Bromine is used to etch aluminum, copper, and semi-conductors. Bromine and its salts are known to recover gold and other precious metals from their ores. Bromine can be used to desulfurize fine coal (see Coal conversion processes). Table 5 shows estimates of the primary uses of bromine. 

Chemical erosion can be suppressed by doping with substitutional elements such as boron. This is demonstrated in Fig. 14 [47] which shows data for undoped pyrolitic graphite and several grades of boron doped graphite. The mechanism responsible for this suppression may include the reduced chemical activity of the boronized material, as demonstrated by the increased oxidation resistance of B doped carbons [48] or the suppressed diffusion caused by the interstitial trapping at boron sites. 

Fig. 14. Chemical yield as a function of temperature for boron doped graphites.

Fig. 2. Raman spectra (T = 300 K) from various sp carbons using Ar-ion laser excitation (a) highly ordered pyrolytic graphite (HOPG), (b) boron-doped pyrolytic graphite (BHOPG), (c) carbon nanoparticles (dia. 20 nm) derived from the pyrolysis of benzene and graphitized at 2820°C, (d) as-synthesized carbon nanoparticles ( 850°C), (e) glassy carbon (after ref. [24]).

A boron-doped diamond electrode was used as prepared. 

An electrochemically oxidized boron-doped diamond electrode was used. The observed rates were concentration-dependent. 

Highly boron doped diamond film supplied by Naval Research Laboratory, USA. 

As is well known, many experimental smdies have been made extensively to search for a possibility of encapsulation of atoms by hollow fullerenes since the discovery of Cgo by Kroto et al. [143]. These methods, however, usually require high tempratures and high pressures, or ion implantation. The yields are also as low as 0.4—10 %. In this sense, the efficiency in our case is much higher and the required conditions are much milder with collison energy of 2 eV. However, the boron substimtion is a bottle neck, although Smalley and co-workers successfully synthesized boron-doped fullerenes [144]. 

This contribution Is concerned with the magnetic and Mossbauer characterization of (a) Fe/zeollte (mordenlte) systems, and that of (b) Fe and/or Ru on boron-doped carbon substrates. Some correlations between the characterization and CO hydrogenation parameters will be pointed out. Because of limitations of space, we shall present salient features of these Investigations. At the outset. It would be befitting to present a succinct background on the basic principles of magnetic and Mossbauer characterization. 

The CMC and boronated samples showed a Landau diamagnetism which changed over to almost the Langevln diamagnetism with progressive boron doping (8). The results were Interpreted in terms of the equation... 

Figure 9. Variation of the diamagnetic susceptibility as a function of boron doping.

Figure 10. The variation in the Fermi level Ep [left hand scale] and the TOF for Nco and Nci [right hand scale (xl0-3g-lpes" )], both as a function of boron doping.

Yagi I, Ishida T, et al. 2004. Electrocatal)tic reduction of oxygen to water at Au nanoclusters vacuum-evaporated on boron-doped diamond in acidic solution. Electrochem Commun 6 773-779. 

Finally, the presence of ultrasound in the electrodeposition of metals can produce both massive metal and metal colloid [75]. The reduction of AuCLt- at polycrystalline boron-doped diamond electrodes follows two pathways forming... 

Holt KB, Sabin G, Compton RG et al (2002) Reduction of tetrachloroaureate(III) at boron-doped diamond electrodes gold deposition versus gold colloid formation. Electroanalysis 14 797-803... 

Saterlay AJ, Wilkins SJ, Holt KB et al (2001) Lead dioxide deposition and electrocalysis at highly boron-doped diamond electrodes in the presence of ultrasound. J Electrochem Soc 148 E66-E72... 

Saez V, Gonzalez-Garcia J, Kulandainathan MA et al (2007) Electro-deposition and stripping of catalytically iron metal nanoparticles at boron-doped diamond electrodes. Electrochem Commun 9 1127-1133... 

Couto et al. [11] developed a flow injection system with potentiometric detection for determination of TC, OTC, and CTC in pharmaceutical products. A homogeneous crystalline CuS/Ag2S double membrane tubular electrode was used to monitor the Cu(II) decrease due to its complexation with OTC. The system allows OTC determination within a 49.1 1.9 x 103 ppm and a precision better than 0.4%. A flow injection method for the assay of OTC, TC, and CTC in pharmaceutical formulations was also developed by Wangfuengkanagul et al. [12] using electrochemical detection at anodized boron-doped diamond thin-film electrode. The detection limit was found to be 10 nM (signal-to-noise ratio = 3). 

Wangfuengkanagul and Chailapakul [9] described the electroanalysis of ( -penicillamine at a boron-doped diamond thin film (BDD) electrode using cyclic voltammetry. The BDD electrode exhibited a well-resolved and irreversible oxidation voltammogram, and provided a linear dynamic range from 0.5 to 10 mM with a detection limit of 25 pM in voltammetric measurement. In addition, penicillamine has been studied by hydrodynamic voltammetry and flow injection analysis with amperometric detection using the BDD electrode. 

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