Electrode formation

Socol Y, Abramson O, Gedanken A et al (2002) Suspensive electrode formation in pulsed sonoelectrochemical synthesis of silver nanoparticles. Lagmuir 18 4736-4740... 

This would give rise to two semicircles in the complex plane, as discussed above, together, possibly, with a Warburg region if this can be resolved. In fact this behaviour is indeed seen close to the onset of iron dissolution in acidic media but at slightly higher potentials. As the local concentration of Fe(II) rises near the electrode, formation of insoluble Fe(OH)2 takes place as ... 

Liu and Fedkiw proposed another SPE electrode formation method, in which cationic salt of platinum instead of chloroplatinic acid, which is used by Takenaka and Torikai, was first impregnated in Nafion and was later reduced chemically. a They showed that product distribution varies depending on the way of the deposition and oxidation conditions. ... 

FIGURE 2.32 The electrode formation on glass by metal lift-off technique without deposition on the channel sidewalls [141]. Reprinted with permission from Wiley-VCH Verlag. 

Chiral Electrode Formation. This was described in Section 11.3. 

Anodization — Formation of a film on an electrode by means of an anodic (oxidation) process. Electrooxidation of silver in a chloride-containing solution results in the formation of an AgCl-film because the solubility product of AgCl is rapidly surpassed upon oxidation of silver. The AgCl-coated silver is suitable for preparation of a Ag/AgCl -> reference electrode. Formation of an oxide layer on other metals (e.g., in case of aluminum) may result in improved surface properties (corrosion resistance, hardness, optical properties). 

Two major classes of technology are used for electrode formation. 

At frequencies below 63 Hz, the double-layer capacitance began to dominate the overall impedance of the membrane electrode. The electric potential profile of a bilayer membrane consists of a hydrocarbon core layer and an electrical double layer (49). The dipolar potential, which originates from the lipid bilayer head-group zone and the incorporated protein, partially controls transmembrane ion transport. The model equivalent circuit presented here accounts for the response as a function of frequency of both the hydrocarbon core layer and the double layer at the membrane-water interface. The value of Cdl from the best curve fit for the membrane-coated electrode is lower than that for the bare PtO interface. For the membrane-coated electrode, the model gives a polarization resistance, of 80 kfl compared with 5 kfl for the bare PtO electrode. Formation of the lipid membrane creates a dipolar potential at the interface that results in higher Rdl. The incorporated rhodopsin may also extend the double layer, which makes the layer more diffuse and, therefore, decreases C. ... 

One of the critical operating junctions in OFET devices is the source and drain contact to the channel. Any barrier between the contacts and the channel will appear in series and impede the flow of charge through the device. The source and drain electrode formation and structure can also influence the properties of the transistor channel itself. Crystal growth nucleated on the source and drain and the processes used to pattern the source and drain electrodes can have a significant effect on overall device performance. 

Electrode formation, adsorption of gas impurities, microstructural changes... 

Heischmann, M. and HiU, I.R. (1983) Surface-enhanced Raman scattering from silver electrodes formation and photolysis of chemisorbed pyridine species. Journal of Electroanalytical Chemistry, 146, 353. 

Figure 19.13. SEM top view and TEM side view of a nan-equilibrium impregnation-reduction electrode. Deposition conditions 0.6 mM Pt(NH3)4Cl2,1 mM NaBHi, 40 minutes impregnation time, 2 hours reduction time, 50 C [3]. (Reprinted by permission of ECS— The Electrochemical Society, from Liu R, Her W-H, Fedkiw PS. In situ electrode formation on a Nafion membrane by chemical platinization.)...

Liu R, Her W-H, Fedkiw PS. In situ electrode formation on a Nafion membrane by chemical platinization. J Electrochem Soc 1992 139 15-23. 

Multielectrode configuration allows parallelization of the assays. In this way, eight-electrode arrays are available, in a way that material employed in conventional ELISA microtiter plates (8x 12 wells) such as eight-channel micropipettes could be used. This format was employed for detection of antimicrobial sulfonamides in honey [44] or clen-buterol in livestock urine [55] with 8 or 16-electrode arrays, respectively. Apart from these arrays, dual-electrode formats in which both working electrodes share the reference and auxiliary electrodes can be employed for single [45] or multianalyte determinations [143], similarly to what happens with a four-channel SPCE (screen-printed carbon electrode) design for simultaneous bianalyte determination [70] (see also Section 9.7.1). 

Electrochemical Deposition of Mesostructured Electrodes (EASA) The Walcarius team [45] advanced mesoporous silicate-modified electrode formation by showing that cathodic deposition of mesoporous silicate film from a solution containing CTAB and TEOS at pH 3 yields predominantly hexagonal 2-D structures with pores oriented perpendicular to the supporting electrode. Figure 4.20 (modified from Reference 45) depicts a cross-sectional view and top view of the highly oriented porous structure obtained by this method. The method was termed EASA for electroassisted self-assembly. 

Undoubtedly, the quality of the electrode surface plays an important role as demonstrated (especially with quasi-uniform fields) by conditioning phenomena—cleaning and polishing of the electrodes, formation of oxide layers, flow of current modifying the initiation voltage. It has been reported often that the radius of curvature of sharp points could be appreciably modified, the observed erosion being caused by mechanisms not clearly understood (sputtering, cavitation). Similar phenomena are likely to occur on local protrusions at the surfaces of plane or spherical electrodes. 

Trombly N, Mason A (2008) Post-CMOS electrode formation and isolation for on-chip temperature-controlled electrochemical sensors. lET Electron Lett 44(l) 29-30... 

The decomposition of chloro-EC on a graphite electrode (formation of SEI) was investigated using two in situ techniques subtractively normalized interfacial Fourier transform infrared spectroscopy (SNlF ilKS) and differential electrochemical mass spectrometry (OEMS) [45]. The applied analytical methods provided conforming information about the onset of CO2 formation (2.2-2.1 Vvs. U/Li ). Hydrogen is evolved below ca 0.6 VLi/Li. ... 

Singh, S.S. and Brydon, J.E. (1969) Solubility of basic aluminium sulfates at equilibrium in solution and in the presence of montmorillonite. Soil ScL, 107, 12—16. Sipos, P., Capewell, S.G., May, P.M., Hefter, G.T, Laurenczy, G., Lukacs, F., and Roulet, R. (1997) tI-NMR and UV-Vis spectroscopic determination of the formation constants of aqueous thallium(l) hydroxo-complexes. J. Solution Chem., 26, 419-431. Srinivasan, K. and Rechnitz, G.A. (1968) Reaction rate measurements with fluoride ion-selective membrane electrode. Formation kinetics of ferrous fluoride and aluminium fluoride complexes. Anal. Chem., 40, 1818-1825. 

Studies on the interfacial microstructure via high resolution transmission electron microscopy (HRTEM) have been performed to verify the existence of dead layer between BST films and Pt or SrRuOs electrodes. Formations of misfit dislocations, planar fault, and disordered or amorphous regions have been reported [19,27,29-33], More recently, we have observed two distinct types of interfaces between BST films and Pt electrodes via HRTEM [34]. One case is the presence of interfacial layer with distorted structure (type I), as shown in Figure 1 (a). Another case, called type II, is exhibited in Figure 1 (b), in which good interfacial match with no interfacial layer is observed. 

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