1,721,018 research outputs found
ORAL CONTRIBUTION - “Biopolytronics for the computer-assisted fabrication of bioelectronic devices” - PRESENTING AUTHOR
No full text
Hydrotalcite-like compounds as ionophores for the development of anion potentiometric sensors
No full textA double layered hydroxide anionic clay containing chloride or nitrate as the interlayer anion has been used to prepare ion-selective electrodes (ISE) for potentiometric sensing of the intercalated anionic species. The electrodes exhibited a linear range for the potential response to logarithm of concentration: from 5.0 x 10(-5) to 2.0 x 10(-1) M with an average slope equal to - 54.2 mV decade(-1) for chloride and from 2.0 x 10(-4) to 1.0 M with an average slope equal to - 48.3 mV decade-1 for nitrate. The response time was from 1 to 6 min, depending on the analyte concentration; the stability of the signal was quite satisfactory. The effect of interfering ions has been investigated and the values of the relevant selectivity constants have been determined. The lifetime of the sensors was at least 2 weeks. (C) 2000 Elsevier Science B.V. All rights reserved
International symposium on enhanced electrochemical capacitors, ISEECap 2022 foreword
Full text linkThis special issue of Electrochimica Acta is a selection of papers presented at the International Symposium on Enhanced Electrochemical Capacitors - ISEECap 2022 that was held from July 11st to 15th, 2022, in Bologna, Italy
Electrochemical synthesis and spectroscopic studies of polyalkylthiophene bearing NLO chromophoric units
No full textThe electrochemical and spectroelectrochemical redox behaviour of two different monomers, suitable for non-linear optical applications. 3-[6-(4-oxy-4'-nitrostilbene)hexyl]thiophene and 3-{6-[4-(4'-nitrophenyl-azo)phenoxy]hexyl}thiophene, are investigated by cyclic voltammetry. In addition the suitable conditions for an electrochemical synthesis of the homopolymer and copolymer with some alkylthiophenes (3-methylthiophene and 3-hexylthiophene) are studied. The polymeric films obtained are characterised by electrochemical methods, spectroelectrochemical UV-vis-NIR and FT-IR in reflectance and compared with the polymer obtained by a chemical method, cast onto Pt and ITO glass surfaces. (C) 2003 Elsevier Science B.V. All rights reserved
Electrodes Coated by Hydrotalcite-like Clays. Effect of the Metals and the Intercalated Anions on Ion Accumulation and Retention Capability
No full textThe influence of the nature of the di- and trivalent metals and of the interlayer anion of different hydrotalcite-like (HT) clays on the anion-exchange ability is investigated. In view of the application of similar clays as electrode coatings in electroanalysis and electrocatalysis, the responses of electrodes modified with the different HT to electroactive species in solution constitute the primary source of information. However, XRD measurements have proved to be invaluable tools when coupled with the electrochemical data. Two organic and one inorganic anion with reversible redox behaviour, i.e. anthraquinone mono-and disulphonates and hexacyanoferrate(II), have been chosen as electroactive species
Anionic clay modified electrode for detection of alcohols. An electrocatalytic amperometric sensor
No full textThe mechanism of the electrocatalytic oxidation towards a wide series of alcohols, by an electrode covered with the [Ni/Al-Cl] hydrotalcyte-like clay, has been analyzed in the different steps it consists of. Such a clay has been reported to be electrically conductive via a mechanism that shows similarities with that of the redox polymers. The overall process occurs in quite a complicated physical system that is completely different both from a classical electrode-solution one and from an electrode covered with a film of heterogeneous catalyst. By varying the characteristics of the substrate, in terms of steric hindrance and dipole moment of the molecule, the factors affecting the redox mediator-substrate reaction have been studied. The concentration ranges where the amperometric response varies linearly have been determined for the different substrates considered
Modification of Electrodes with Porphirin-functionalysed Conductive Polymers
No full textA new thiophene derivative has been synthesised, in which a porphyrin moiety has been inserted in the beta position of the heterocyclic ring. The homopolymer deriving from this monomer has been prepared by chemical oxidation and subsequently deposited on a glassy carbon electrode, while the copolymer with dithiophene has been generated electrochemically directly on the electrode surface. Both materials have been characterised by SEM, and by UV-visible and IR spectroscopies. The electrochemical behaviour of the relevant coatings has been studied and the complexing ability of the polymer chains has been investigated with respect to the Ni(II) ion
Electrocatalytic Properties of Nickel(II) Hydrotalcyte-type Anionic Clay. Application to Methanol and Ethanol Oxidation.
No full textGlassy carbon electrodes modified with a [Ni/Al-Cl] hydrotalcite-type anionic clay have been studied with respect to the electrochemical oxidation of the NI(II) centres. The oxidation of Ni(II) is quasi-reversible and the presence in the hydrotalcite lattice of nickel with mixed oxidation states increases the conductivity of the coverage strongly. It has been verified that these nickel redox systems may act as redox mediators for the oxidation of alcohol substrates (methanol and ethanol have been tested) which are not oxidised at the bare electrode in the potential window available. For both alcohols the height of the current responses in linear sweep voltammetry is roughly linear with varying concentration in solution up to a limit of ca. 3000 ppm, with a detection limit of 3-4 ppm
- …
