Microcrystalline diamond thin

Ru(NH3)6, 0.1 mM IrClg, and 0.05 mM methyl viologen (MV ) at a boron-doped microcrystalline diamond thin-film electrode. Scan rate = 0.1 V/s. Electrolyte = 1 M KCl. 

Cyclic Voltammetric and Heterogeneous Electron Transfer Rate Constant Data for Four Aqueous-Based Redox Systems at Boron-Doped Microcrystalline Diamond Thin-Film Electrodes... 

Figure 18 shows typical cyclic voltammetric i-E curves for 1.0 mM (A) cadaverine (CAD), (B) putrescine (PUT), (C) spermidine (SPMD), and (D) 0.8 mM spermine (SPM) in borax buffer pH 11 (BBpHll) at a microcrystalline diamond thin film deposited from a 0.5% CH4/H2 ratio and 10 ppm B2H6. Similarly shaped curves were observed for several other amines and polyamines (e.g., methylamine, ethylamine, propylamine, ethylenediamine, 1,3-diaminopropane, 1,6-hexamethylenediamine, and... 

Figure 23B presents IR transmission spectra for (5) an optically pure and mechanically polished white diamond disc, (6) an undoped and polished (both sides) Si substrate, and (7 and 8) moderately and heavily boron-doped microcrystalline diamond thin films deposited on the undoped Si. The white diamond is relatively free of structural defects and chemical impurities. There is reduced transparency between 2500 and 1500 cm due to the two-phonon absorption. Diamond films with more... 

FIG. 23. Transmission spectra for different materials in the (A) UV/Vis and (B) IR regions of the electromagnetic spectrum. The electrodes in (A) are (1) a thin film of ITO on quartz, (2) a thin film of boron-doped nanocrystalline diamond on quartz, (3) a thin film of mechanically polished and boron-doped diamond on an optically pure, white diamond substrate, and (4) a free-standing, boron-doped, and mechanically polished diamond disc. The electrodes in (B) are (5) an optically pure and mechanically polished white diamond disc, (6) an undoped and polished (both sides) Si substrate, and (7 and 8) moderately and heavily boron-doped microcrystalline diamond thin films deposited on the undoped Si. (Reprinted with permission from Interface 2003, 12, 33. Copyright (2003) The Electrochemical Society, Inc.) (From Ref. 158.)... 

Diamond OTEs are also useful for studying the electrochemical and optical properties of important biomolecules, like cytochrome c. We recently reported that boron-doped microcrystalline diamond thin film electrodes are quite responsive for horse heart cytochrome c, exhibiting a very active and stable cyclic voltammetric response without any pretreatment or surface modification [119,124]. Heterogeneous electron-transfer... 

Fig. 3 Microcrystalline CVD diamond thin film on a cemented carbide substrate (Source Institute for Machine Tools and Factory Management (IWF), Technische Universitat Berlin)...

Fig. 5 SEM images of (a) a boron-doped microcrystalline and (b) a boron-doped nanocrystalline diamond thin film grown on Si.

There are two types of synthetic diamond thin film routinely produced microcrystalline and nanocrystalline [2]. 

The names for these two film types arise from their nominal crystallite size and morphology. Figure 5 shows scanning electron microscopy (SEM) images of the two types of boron-doped diamond thin film deposited on Si. High quality microcrystalline diamond films are deposited from CH4/H2 source gas mixtures with volumetric ratios of 0.3 to 1.0%,... 

Fig. 10 First scan-cyclic voltammetric i—E curves for the reduction of 4-nitrophenyl diazonium tetrafluoroborate at microcrystalline and nanocrystalline diamond thin-film electrodes. Scan rate = 100 mV s h...

FIG. 2. SEM images of boron-doped (A) microcrystalline and (B) nanocrystalline diamond thin films. 

IV. CHARACTERIZATION OF MICROCRYSTALLINE AND NANOCRYSTALLINE DIAMOND THIN FILM ELECTRODES... 

Figure 7 shows x-ray diffraction patterns for moderately boron-doped ( 10 cm ) microcrystalline and nanocrystalline diamond thin... 

FIG. 7. X-ray diffraction patterns for a boron-doped (a) microcrystalline and (b) nanocrystalline diamond thin film. 

Figure 8 shows visible-Raman spectra for moderately boron-doped ( — 10 cm ) microcrystalline and nanocrystalline diamond thin films. The spectrum for the microcrystalline film consists of the one-phonon diamond line centered at 1333 cm The line width (FWHM) is ca. 10 cm and, to a first approximation, is inversely related to the phonon lifetime [123,130]. The line position is negligibly shifted from that for a reference... 

Cyclic voltammetric measurements were made using well-characterized microcrystalline, boron-doped diamond thin-film electrodes to test the material s responsiveness for ferrocene as a function of scan rate, solvent. 

Bennett, J.A., Y. Show, S.H. Wang et al. 2005. Pulsed galvanostatic deposition of Pt particles on microcrystalline and nanocrystalline diamond thin-film electrodes. Journal of Electrochemical Society 152 E184-E192. 

Muna, G. W., Tasheva, N. and Swain, G. M. (2004), Electro-oxidation and amperometric detection of chlorinated phenols at boron-doped diamond electrodes A comparison of microcrystalline and nanocrystalline thin films. Environ. Sci. Technol., 38(13) 3674-3682. 

CCL-Diamond, http //www.ccl diamond.com/HTML/Products Electrodes.html Microcrystalline thin-film BDD electrodes Coated on Ti, W, Mb, Si... 

One important electrochemical technology where diamond electrodes have made a significant impact is in the area of electroanalysis. CVD diamond offers advantages over other electrodes, especially sp carbon (e.g., glassy carbon), in terms of linear dynamic range, limit of detection, response time, response precision, and response stability. Some of the reported applications of diamond in electroanalysis are highlighted below. Unless stated otherwise, all the diamond electrodes mentioned below are boron-doped, microcrystalline thin films deposited on a conducting substrate (e.g.. Si). 

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