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Electrochemical Windows (electrochemical + window)

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Chemistry100%

Selected Abstracts

Widening the Voltammetric Window Using Regular Arrays of Microdisk Electrodes

ELECTROANALYSIS, Issue 16 2007
Francois
Abstract This work explores, through mathematical modeling and numerical simulation, the use of regular arrays of microdisk electrodes wired in parallel as a means to increase the width of the electrochemical window in which one can carry out electrochemical experiments. [source]

Electrodeposition of Metals and Semiconductors in Air- and Water-Stable Ionic Liquids

CHEMPHYSCHEM, Issue 1 2006
Sherif Zein El Abedin Prof. Dr.
Abstract In addition to their stability, the advantages of air- and water-stable ionic liquids over chloroaluminate ionic liquids, which were intensively investigated in the past, are that they are easy to dry, purify, and handle. Moreover, some of these ionic liquids have an extremely large electrochemical window of more than 5 V, and hence they give access to the electrodeposition of many metals and semiconductors, such as Ta, Ti, Si, and Ge. The results to date for the electrodeposition of metals and semiconductors in the most popular air- and water-stable ionic liquids are presented. [source]

Fabrication, Characterization, and Application of ,Sandwich-Type' Electrode Based on Single-Walled Carbon Nanotubes and Room Temperature Ionic Liquid

ELECTROANALYSIS, Issue 17 2008
Xuzhi Zhang
Abstract The much-enhanced electrochemical responses of potassium ferricyanide and methylene blue (MB) were firstly explored at the glassy carbon electrode modified with single-walled carbon nanotubes (SWNT/GCE), indicating the distinct electrochemical activity of SWNTs towards electroactive molecules. A hydrophobic room temperature ionic liquid (RTIL), 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6), was used as electrode modification material, which presented wide electrochemical windows, proton permeation and selective extraction ability. In consideration with the advantages of SWNTs and RTIL in detecting target molecules (TMs), a novel strategy of ,sandwich,type' electrode was established with TMs confined by RTIL between the SWNT/GCE and the RTIL membrane. The strategy was used for electrochemical detection of ascorbic acid (AA) and dopamine (DA), and detection limits of 400 and 80 fmol could be obtained, respectively. The selective detection of DA in the presence of high amount of AA could also be realized. This protocol presented many attractive advantages towards voltammetric detection of TMs, such as low sample demand, low cost, high sensitivity, and good stability. [source]

Tetraalkylammonium Salts of Weakly Coordinating Aluminates: Ionic Liquids, Materials for Electrochemical Applications and Useful Compounds for Anion Investigation

CHEMISTRY - A EUROPEAN JOURNAL, Issue 8 2009
Ines Raabe Dr.
Abstract Weak and robust? Tetraalkylammonium salts of weakly coordinating fluorinated alkoxyaluminates are easily accessible, chemically robust materials that show interesting physico-chemical properties like low melting points, high electrochemical stability and electric conductivity in weakly polar solvents such as CH2Cl2, Ph-F and toluene. In this study, we investigated the tetraalkylammonium salts of the weakly coordinating fluorinated alkoxyaluminates [pftb], ([Al(O(C(CF3)3)4],), [hfip], ([Al(OC(H)(CF3)2)4],) and [hftb], ([Al(OC(CH3)(CF3)2)4],) in order to obtain information on their undisturbed spectral and structural properties, as well as to study their electrochemical behavior (i.e., conductivities in non-polar solvents and electrochemical windows). Several of the compounds qualify as ionic liquids with melting points as low as 42,°C for [NBu4]+[hfip],. Simple and almost quantitative metathesis reactions yielding these materials in high purity were developed. These [NR4]+ salts serve as model compounds for undisturbed anions and their vibrational spectra,together with simulated spectra based on quantum chemical DFT calculations,were used for the clear assignment of the anion bands. Besides, the ion volumes of the anions (Vion([pftb],)=0.736,nm3, Vion([hftb],)=0.658,nm3, Vion([hfip],)=0.577,nm3) and their decomposition pathways in the mass spectrometric measurements have been established. The salts are highly soluble in non-polar solvents (up to 1.09,mol,L,1 are possible for [NBu4]+[hftb], in CH2Cl2 and 0.41,mol,L,1 for [NBu4]+[hfip], in CHCl3) and show higher molar conductivities if compared to [NBu4]+[PF6],. The electrochemical windows of CH2Cl2, CH3CN and 1,2-F2C6H4 using the [NBu4]+ aluminate electrolytes are up to +0.5,V/,0.7,V larger than those using the standard [NBu4]+[PF6],. [source]

Cyclic Quaternary Ammonium Ionic Liquids with Perfluoroalkyltrifluoroborates: Synthesis, Characterization, and Properties

CHEMISTRY - A EUROPEAN JOURNAL, Issue 8 2006
Zhi-Bin Zhou Dr.
Abstract New cyclic quaternary ammonium salts, composed of N -alkyl(alkyl ether)- N -methylpyrrolidinium, -oxazolidinium, -piperidinium, or -morpholinium cations (alkyl=nC4H9, alkyl ether=CH3OCH2, CH3OCH2CH2) and a perfluoroalkyltrifluoroborate anion ([RFBF3],, RF=CF3, C2F5, nC3F7, nC4F9), were synthesized and characterized. Most of these salts are liquids at room temperature. The key properties of these salts,phase transitions, thermal stability, density, viscosity, conductivity, and electrochemical windows,were measured and compared to those of their corresponding [BF4], and [(CF3SO2)2N], salts. The structural effect on all the above properties was intensively studied in terms of the identity of the cation and anion, variation of the side chain in the cation (i.e., alkyl versus alkyl ether), and change in the length of the perfluoroalkyl group (RF) in the [RFBF3], ion. The reduction of Li+ ions and reoxidation of Li metal took place in pure N -butyl- N -methylpyrrolidinium pentafluoroethyltrifluoroborate as the supporting electrolyte. Such comprehensive studies enhance the knowledge necessary to design and optimize ionic liquids for many applications, including electrolytes. Some of these new salts show desirable properties, including low melting points, high thermal stabilities, low viscosities, high conductivities, and wide electrochemical windows, and may thus be potential candidates for use as electrolytes in high-energy storage devices. In addition, many salts are ionic plastic crystals. [source]