1,721,088 research outputs found
Additional Recent Applications and Prospects
No full textA brief overview about additional recent applications and developments of scanning electrochemical microscopy (SECM) is given in order to demonstrate to the reader the large potential and flexibility that SECM, as a technique alone or in combination with other techniques, provides. The electrode-electrolyte interface changes dynamically during almost all electrochemical processes. In order to study these changes, many efforts are being made to combine electrochemical measurements with techniques that enable the spectroscopic characterization of the electrochemical interface in real time. One approach is the in situ parallel measurement of the electrochemical reactivity and of the vibrational modes of micrometric sample sites by combining SECM with Raman spectroscopy. The implementation of electrochemical impedance microscopy (EIS) in SECM measurements is known as scanning EIS (SEIM). Finally, a conclusion is drawn with an outlook on the expected future developments and applications of SECM
Surface Patterning with Fluorescent Molecules Using Click Chemistry Directed by Scanning Electrochemical Microscopy
No full textDynamic Potential-Ph Diagrams Application to Electrocatalysts for Water Oxidation
Get PDFThe construction and use of "dynamic potential-pH diagrams" (DPPDs), that are intended to extend the usefulness of thermodynamic Pourbaix diagrams to include kinetic considerations is described. As an example, DPPDs are presented for the comparison of electrocatalysts for water oxidation, i.e., the oxygen evolution reaction (OER), an important electrochemical reaction because of its key role in energy conversion devices and biological systems (water electrolyses, photoelectrochemical water splitting, plant photosynthesis). The criteria for obtaining kinetic data are discussed and a 3-D diagram, which shows the heterogeneous electron transfer kinetics of an electrochemical system as a function of pH and applied potential is presented. DPPDs are given for four catalysts: IrO(2), Co(3)O(4), Co(3)O(4) electrodeposited in a phosphate medium (Co-Pi) and Pt, allowing a direct comparison of the activity of different electrode materials over a broad range of experimental conditions (pH, potential, current density). In addition, the experimental setup and the factors affecting the accurate collection and presentation of data (e. g., reference electrode system, correction of ohmic drops, bubble formation) are discussed.Ministry of Education, University and Research PRIN 2008PF9TWZ, 2008N7CYL5Universita degli Studi di MilanoNational Science Foundation CHE-0808927Robert A. Welch Foundation F-0021Center for Electrochemistr
Direct determination of diffusion coefficients by chronoamperometry at microdisk electrodes
No full textThe chronoamperometric response at a microdisk is used for the direct determination of the diffusion coefficient of an electroactive species. The method does not require knowledge of the bulk concentration and the number of electrons participating in the electrode reaction, and requires only a value for the disk radius. Subsequent determination of the number of electrons (n) for an electrode reaction or the concentration of electroactive species is also possible. This approach is demonstrated with the evaluation of the diffusion coefficient of Fe(CN)6(4-) in KCl and that of borohydride ion in NaOH. In both cases, the values of n found remained constant over a wide time range and correspond to those expected for these processes
Scanning electrochemical microscopy - a new technique for the characterization and modification of surfaces
No full textScanning electrochemical microscopy: theory and application of the transient (chronoamperometric) SECM response
No full textA study of the transient (chronoamperometric) response of the scanning electrochemical microscope (SECM) is presented. SECM transients were simulated digitally with a novel integrator based on a Krylov algorithm. The transients observed with planar electrodes (PE), microdisks (MD), and thin-layer cells (TLC) are shown to be limiting cases that fit the simulated SECM transients at very short, intermediate, and long times, respectively. A procedure is established that, provided the tip radius is known, allows the determination of the diffusion coefficient of the species in solution independent of its concentration and the number of electrons transferred in the electrode reaction. Experimental SECM transients are reported for the electrochemical oxidation of Fe(CN)64- in KCl; the diffusion coefficient of Fe(CN)6(4-) was found to agree very well with the literature value
Electrogenerated chemiluminescence (ECL) of 2-oxa-bicyclo[3.3.0]octa-4,8-diene-3,6-dione (OBDD)
No full textSynthesis, Electrochemistry, and Electrogenerated Chemiluminescence of Azide-BTA, a D-A-pi-A-D Species with Benzothiadiazole and N,N-Diphenylaniline, and Its Nanoparticles
No full textElectrochemistry and Electrogenerated Chemiluminescence of 3,6-Di(spirobifluorene)-N-phenylcarbazole
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