Glassy carbon electrodes preparation

Yin J, Jia J, Zhu L (2008) Macroporous Pt modified glassy carbon electrode preparation and electrocatalytic activity for methanol oxidation. Int J Hydrogen Energy 33 7444-7447... 

Uestuendag Z, Solak AO (2009) EDTA modified glassy carbon electrode preparation and characterization. Electrochim Acta 54 6426-6432... 

Glassy carbon electrodes polished with alumina and sonicated under clean conditions show activation for the ferrl-/ ferro-cyanlde couple and the oxidation of ascorbic acid. Heterogeneous rate constants for the ferrl-/ ferro-cyanlde couple are dependent on the quality of the water used to prepare the electrolyte solutions. For the highest purity solutions, the rate constants approach those measured on platinum. The linear scan voltammetrlc peak potential for ascorbic acid shifts 390 mV when electrodes are activated. 

The purpose of this paper Is 1) to describe the electrochemistry of ferrl-/ferro-cyanlde and the oxidation of ascorbic at an activated glassy carbon electrode which Is prepared by polishing the surface with alumina and followed only by thorough sonlcatlon 2) to describe experimental criteria used to bench-mark the presence of an activated electrode surface and 3) to present a preliminary description of the mechanism of the activation. The latter results from a synergistic Interpretation of the chemical, electrochemical and surface spectroscopic probes of the activated surface. Although the porous layer may be Important, Its role will be considered elsewhere. 

Another electro-oxidation example catalyzed by bimetallic nanoparticles was reported by D Souza and Sam-path [206]. They prepared Pd-core/Pt-shell bimetallic nanoparticles in a single step in the form of sols, gels, and monoliths, using organically modified silicates, and demonstrated electrocatalysis of ascorbic acid oxidation. Steady-state response of Pd/Pt bimetallic nanoparticles-modified glassy-carbon electrode for ascorbic acid oxidation was rather fast, of the order of a few tens of seconds, and the linearity was observed between the electric current and the concentration of ascorbic acid. 

J. Qu, Y. Shen, X. Qu, and S. Dong, Preparation of hybrid thin film modified carbon nanotubes on glassy carbon electrode and its electrocatalysis for oxygen reduction. Chem. Commun. 1, 34—35... 

Figure 1. Cyclic voltammograms in MeCN(0.1M tetra-ethylammonium perchlorate) for the oxidation of (a) a copper electrode, (b) 3 mM "OH at a glassy carbon electrode, (c) 0.5 mM "OH at a copper electrode, and (d) 3 mM "OH at a copper electrode. Scan rate, 0. IV s"1 electrode area, 0.08 cm2 copper electrode prepared by electroplating Cu(C104) onto a glassy carbon electrode (GCE). ...

Zhao et al. prepared magnetite (FesO nanoparticles modified with electroactive Prussian Blue [44]. These modified NPs were drop-cast onto glassy-carbon electrodes. They observed the redox processes commonly observed for PB (similar to that seen in Figure 4.8), and also demonstrated that the Prussian White material produced by PB reduction at 0.2 V served as an electrocatalyst for Fi202 reduction. They also prepared LbL films in which PB NPs and glucose oxidase were alternated between PD DA layers [99]. These were demonstrated to act as electrocatalysts for Fi202 reduction. Based on the ability to sense the product of the enzymatic reaction, these structures were shown to act as glucose sensors. 

There are a few reports of poly(naphthalene) thin films. Yoshino and co-workers. used electrochemical polymerization to obtain poly(2,6-naphthalene) film from a solution of naphthalene and nitrobenzene with a composite electrolyte of copper(II) chloride and lithium hexafluoroarsenate. Zotti and co-workers prepared poly( 1,4-naphthalene) film by anionic coupling of naphthalene on. platinum or glassy carbon electrodes with tetrabutylammonium tetrafluoroborate as an electrolyte in anhydrous acetonitrile and 1,2-dichloroethane. Recently, Hara and Toshima prepared a purple-colored poly( 1,4-naphthalene) film by electrochemical polymerization of naphthalene using a mixed electrolyte of aluminum chloride and cuprous chloride. Although the film was contaminated with the electrolyte, the polymer had very high thermal stability (decomposition temperature of 546°C). The only catalyst-free poly(naphthalene) which utilized a unique chemistry, Bergman s cycloaromatization, was obtained by Tour and co-workers recently (vide infra). 

Bond and coworkers [521] have described Au(III) electroreduction and Au(0) oxidation stripping processes in dilute aqua regia utilizing platinum, rhodium, iridium, gold, and glassy carbon electrodes. Sorption of tetrachloroaureate ions on carbon paste electrode modified with montmorillonite has been performed as a preconcentration step in the determination of gold in pharmaceutical preparation [522]. 

Film Electrodes and Related Hg Electrodes Mercury films were prepared on reticulated vitreous carbon flowthrough electrodes by Hg deposition from Hg + solutions in acetic buffer [31]. Such an electrode was designed for the purposes of trace metal analysis. Mercury film de-position/oxidation on reticulated vitreous carbon and glassy carbon electrodes were compared. 

Measured by conventional cyclic voltammetry. A monolayer of 28 (R BuO prepared on water and compressed at 25 mN m, was transferred on a glassy carbon electrode by the Langmuir-Blodgen method. The markers were added as Na4[Fe(CN)J, mcthylviologen dichloride, orp-quinone (1,4-benzoquinone) (1.00 X 10 M concentration in all cases). 

A nitrate-selective potentiometric MIP chemosensor has been devised [197, 198]. For preparation of this chemosensor, a polypyrrole film was deposited by pyrrole electropolymerization on a glassy carbon electrode (GCE) in aqueous solution of the nitrate template. Potentiostatic conditions of electropolymerization used were optimized for enhanced affinity of the resulting MIP film towards this template. In effect, selectivity of the chemosensor towards nitrate was much higher than that to the interfering perchlorate ( o3 cio4 = 5.7 x 10-2) or iodide ( N03, r = x 10 2) anion. Moreover, with the use of this MIP chemosensor the selectivity of the nitrate detection has been improved, as compared to those of commercial ISEs, by four orders of magnitude at the linear concentration range of 50 pM to 0.5 M and LOD for nitrate of (20 10) pM [197]. 

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