Search results for "electrochemical"

Grand canonical rate theory for electrochemical and electrocatalytic systems I: General formulation and proton-coupled electron transfer reactions

2020

A generally valid rate theory at fixed potentials is developed to treat electrochemical and electrocatalytic potential-dependent electron, proton, and proton-coupled electron reactions. Both classical and quantum reactions in adiabatic and non-adiabatic limits are treated. The applicability and new information obtained from the theory is demonstrated for the gold catalyzed acidic Volmer reaction.

Nanosized hydrophobic gels: Advanced supramolecules for use in electrochemical bio- and immunosensing

2018

Abstract Nanosized hydrogels have emerging as versatile supramolecules materials with application in various electrochemical biosensing devices. This review reports a systematic study of the usefulness of nano-sized hydrogels in the different steps of the process of development of electrochemical biosensing systems. The advantages offered by nano-sized hydrogels in detection of analytes are illustrated with representative recent examples that highlight the scientific interest in widening the use of hydrogel nanoparticles in electrochemical biosensing methods. In this review, different types of hydrogel nanoparticles-based electrochemical biosensors, such as enzyme, protein, and nucleic acid…

Nanostructured electrodes for hydrogen production in alkaline electrolyzer

2018

Abstract Ever-widespread employment of renewable energy sources, such as wind and sun, request the simultaneous use of effective energy storage systems owing to the intermittent and unpredictable energy generation by these sources. The most reliable storage systems currently under investigation are batteries and electrochemical cells for hydrogen production from water splitting. Both systems store chemical energy which can be converted on demand. The low power density is the weakness of the batteries while the high production cost limits currently the wide use of hydrogen from electrochemical water splitting. In this work, attention was focused on the use of nanostructured Ni as a cathode f…

Influence of applied strain on the microstructural corrosion of AlMg2 as-cast aluminium alloy in sodium chloride solution

2012

International audience; The corrosion behavior of ISO AlMg2 (AA5052) was studied at the microscale using the Electrochemical Microcell Technique. The influence of plastic deformation on the corrosion resistance of this alloy was also examined. After polishing, pitting at small copper-enriched precipitates and structural etching were observed. After deformation, numerous slip bands were found in grains. After 5.5% plastic strain, the global electrochemical behavior of samples was significantly affected. Pitting potential was decreased in sites containing slip bands or in sites with large strain gradients (measured using microgauges deposited by lithography).

Dismantling and electrochemical copper recovery from Waste Printed Circuit Boards in H2SO4–CuSO4–NaCl solutions

2019

Abstract The worldwide growing of electrical and electronic equipment makes increasingly urgent to find environmentally friendly treatments for e-waste. In this paper, the attention has been focused on i) the eco-friendly dismantling of the electronic components from Waste Printed Circuit Boards and ii) recovering of pure metallic copper, which is the most abundant metal and one of the most valuable in Printed Circuit Boards. After an experimental optimization study, we found that a solution containing 0.5 M H2SO4, 0.4 M CuSO4, and 4 M NaCl can be successfully used to disassemble the electronic components from the boards by leaching of all exposed metals. Air was blown into the leaching sol…

Leaded Bronze Alloy as a Catalyst for the Electroreduction of CO 2

2019

A nanostructured sensor of hydrogen peroxide

2017

Abstract A nanostructured electrochemical sensor of hydrogen peroxide was fabricated growing self-standing Pd nanowires (Pd NWs) into polycarbonate (PC) membranes through a simple metal galvanic deposition. Conditions of deposition were adjusted in order to attain 2–5 μm long Pd wires. Characterization of Pd-NWs was performed by scanning electrode microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction. Properties of the nanostructured sensor were studied by cyclic voltammetry and chronoamperometry in phosphate buffer—ethanol solution. Addition of pure ethanol to the test solution was essential in order to increase wettability of the nanostructures. Sensing features were comp…

Pulsed-current versus constant-voltage light-emitting electrochemical cells with trifluoromethyl-substituted cationic iridium(iii) complexes

2013

We report on five cationic iridium(III) complexes with cyclometalating 2-(3′-trifluoromethylphenyl)pyridine and a diimine, [(C⁁N)2Ir(N⁁N)](PF6), N⁁N = 4,4′-R2-2,2′-dipyridyl or 4,7-R2-1,10-phenanthroline (R = H, Me, tert-Bu, Ph), and characterize three of them by crystal structure analysis. The complexes undergo oxidation of the Ir–aryl fragment at 1.13–1.16 V (against ferrocene couple) and reduction of the N⁁N ligand at −1.66 V to −1.86 V, and have a redox gap of 2.84–2.99 V. The complexes exhibit bluish-green to green-yellow phosphorescence in an argon-saturated dichloromethane solution at room temperature with a maximum at 486–520 nm, quantum yield of 61–67%, and an excited-state lifetim…

Influence of Anodic and Thermal Barrier Layers on Physicochemical Behavior of Anodic TiO2 Nanotubes

2011

Electrochemical and photo-electrochemical behavior of self-organized TiO2 nanotubes formed in organic solvents have been studied by taking into account the formation of new barrier layers beneath nanotubes either due to the anodic polarization in aqueous solutions or air exposure during high temperature annealing. It has been shown that before annealing, electrochemical and photoelectrochemical answers are dominantly controlled by the physicochemical properties of the anodic barrier layer. Annealing in air at sufficiently high temperatures changes the initial amorphous structure of as-prepared nanotubes and forms a new oxide layer below them due to thermal oxidation of underneath titanium. …

Photoelectrochemical removal of chlorfenvinphos by using WO3 nanorods: Influence of annealing temperature and operation pH

2019

[EN] A visible-light driven photoelectrochemical degradation process has been applied to a solution polluted with the organophosphate insecticide chlorfenvinphos. Different WO3 nanosheets/nanorods have been used as photoanodes. These nanostructured electrodes have been fabricated by anodization of tungsten and, subsequently, they have been subjected to a thermal treatment (annealing). The combined influence of annealing temperature (400¿°C and 600¿°C) and operation pH (1 and 3) on the photoelectrocatalytic behavior of these nanorods has been examined through a statistical analysis. Morphological, structural and photoelectrochemical characterizations have also been carried out. The chlorfenv…