articles+ search results

General chemistry, physical chemistry, Chimie générale, chimie physique, Energy, Énergie, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Biophysique moleculaire, Molecular biophysics, Chimie physique en biologie, Physical chemistry in biology, Electrochimie, Electrochemistry, Agent surface cationique, Cationic surfactant, Agente superficie catiónico, Anode, Anodo, Biofilm, Bioélectrochimie, Bioelectrochemistry, Bioelectroquímica, Carbone, Carbon, Carbono, Catalyse enzymatique, Enzymatic catalysis, Catálisis enzimática, Electrocatalyse, Electrocatalysis, Electrocatálisis, Electrode microorganisme, Microbial electrode, Electrodo microorganismo, Formation, Formación, Matériau modifié, Modified material, Material modificado, Matériau électrode, Electrode material, Material electrodo, Microorganisme immobilisé, Entrapped microorganism, Microorganismo inmovilizado, Traitement surface, Surface treatment, Tratamiento superficie, Ammonium(hexadécyl triméthyl) bromure, Bioelectrochemical systems, Biofilm formation, Carbon felt, Cetyltrimethylammonium bromide, Surface modification, and Surfactant

This study reports a simple and effective method to make carbon felt surface hydrophilic and positively-charged by means of cetyltrimethylammonium bromide (CTAB) soaking. X-ray photoelectron spectroscopy and cyclic voltammetry indicated that CTAB could form a surfactant layer on carbon felt surface with the polar heads exposing outwardly. In an acetate-fed bioanode, the start-up time of current production and the time to reach stable current output at the CTAB-treated felt anodes were 36.1% and 49.4% shorter than the untreated anodes, respectively. Moreover, the maximum current output with these treated electrodes was 23.8% higher than the untreated counterparts. These results indicate that the CTAB treatment of carbon felt accelerates the anodic biofilm formation and enhances current output of BESs.

General chemistry, physical chemistry, Chimie générale, chimie physique, Energy, Énergie, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Electrochimie, Electrochemistry, Electrodes: préparations et propriétés, Electrodes: preparations and properties, Autres électrodes, Other electrodes, Chimie analytique, Analytical chemistry, Méthodes électrochimiques, Electrochemical methods, Acide carboxylique, Carboxylic acid, Acido carboxílico, Analyse chimique, Chemical analysis, Análisis químico, Analyse quantitative, Quantitative analysis, Análisis cuantitativo, Cadmium II Composé, Cadmium II Compounds, Cadmio II Compuesto, Carbone, Carbon, Carbono, Composé du diazonium, Diazonium compounds, Diazonio compuesto, Cuivre II Composé, Copper II Compounds, Cobre II Compuesto, Dérivé du benzène, Benzene derivatives, Benceno derivado, Détecteur électrochimique, Electrochemical detector, Detector electroquímico, Electrode, Electrodes, Electrodo, Elément trace, Trace element, Elemento traza, Métal lourd, Heavy metal, Metal pesado, Plomb II Composé, Lead II Compounds, Plomo II Compuesto, Préparation, Preparation, Preparación, Relation structure propriété, Property structure relationship, Relación estructura propiedad, Traitement surface, Surface treatment, Tratamiento superficie, Voltammétrie redissolution anodique, Anodic stripping voltammetry, Voltametría redisolución anódica, Electrode sérigraphiée, Screen-printed electrode, Greffage électrochimique, Electrochemical grafting, Carbon-screen-printed electrode, Carboxylic diazonium salt, Environmental analysis, and Trace element detection

The electrochemically induced functionalization of carbon-based screen-printed-electrodes (SPEs) by phenyl groups, having one or two carboxylic functions, was achieved by reduction of in situ generated diazonium salts in aqueous media. The corresponding diazonium cations of 4-aminobenzoic acid, 4-aminophthalic acid, 3-(4-aminophenyl) propionic acid, 3-(4-aminophenyl)-2-propenoic acid and 5-aminoisophthalic acid were generated in situ with sodium nitrite in aqueous H2SO4. The electrochemical detection of Pb(II) with the grafted SPEs was investigated using Pb(II) 5 × 10-8 M solutions. The performances of the grafted SPEs were found to be dependent on the number of carboxylic groups, on their position on the phenyl ring, on the olefinic or the aliphatic character of the chain bearing the carboxylic group. The performances of mono-4-carboxyphenyl and 3,5-dicarboxyphenyl grafted SPEs for Cd(II) and Cu(II) trace detection were tested and compared.

General chemistry, physical chemistry, Chimie générale, chimie physique, Energy, Énergie, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Electrochimie, Electrochemistry, Electrodes: préparations et propriétés, Electrodes: preparations and properties, Autres électrodes, Other electrodes, Métal transition, Transition metal, Metal transición, Antioxydant, Antioxidant, Antioxidante, Carbone, Carbon, Carbono, Cathode, Cátodo, DMF, N,N-Dimethylformamide, Dimetilformamida, Débromation, Debromination, Desbromación, Dérivé de l'anthraquinone, Anthraquinone derivatives, Antraquinona derivado, Electrode stationnaire, Stationary electrode, Electrodo estacionario, Graphène, Graphene, Intercepteur radical, Radical scavenger, Interceptor radical, Matériau modifié, Modified material, Material modificado, Matériau électrode, Electrode material, Material electrodo, Or, Gold, Oro, Quinone, Quinona, Réaction radicalaire, Free radical reaction, Reacción radicalar, Réaction électrochimique, Electrochemical reaction, Reacción electroquímica, Réduction chimique, Chemical reduction, Reducción química, Solvant organique, Organic solvent, Solvente orgánico, Traitement surface, Surface treatment, Tratamiento superficie, Ammonium(tétrabutyl) tétrafluoroborate, Anthraquinone(2-bromométhyl), Greffage électrochimique, Electrochemical grafting, 2-Bromomethylanthraquinone, Anthraquinone electrodes, Gold redox surfaces, and Graphene-gold interface

Gold (smooth or covered with a thin layer of graphene) is an efficient free-radical scavenger when used as cathode material. This first work points out the immobilization of anthraquinone (AQ) in organic polar solvents containing tetraalkylammonium salts. It appears that Au and graphene, when negatively polarized (E > — 1.0 V vs. Ag/AgCl), may react towards 2-bromomethylantraquinone (AQ―CH2―Br) in different ways: with Au, a fast adsorption followed by one-electron transfer leads to a robust radical modification of the interface, whereas the presence of graphene permits the formation of a benzyl-type radical readily trapped by the graphene layer. Two different redox stable electrodes are thus produced. Additionally, stability of gold―graphene―AQ electrodes could be successfully tested in aqueous buffered solutions.

General chemistry, physical chemistry, Chimie générale, chimie physique, Energy, Énergie, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Electrochimie, Electrochemistry, Electrodes: préparations et propriétés, Electrodes: preparations and properties, Autres électrodes, Other electrodes, Alkylation, Alquilación, Article synthèse, Review, Artículo síntesis, Carbone, Carbon, Carbono, Carboxylation, Carboxilación, Etat vitreux, Glassy state, Estado vitreo, Fonctionnalisation, Functionalization, Funciónalización, Matériau électrode, Electrode material, Material electrodo, Mécanisme SN2, SN2 mechanism, Mecanismo SN2, Mécanisme réaction, Reaction mechanism, Mecanismo reacción, Nucléophile, Nucleophile, Nucleófilo, Traitement surface, Surface treatment, Tratamiento superficie, Glassy carbon, Poly-nucleophile, and Surface modification via SN2

During the last decade, various carbon modifications were achieved via radical addition of substituted aryl radicals produced at the surface by chemical or/and electrochemical reduction of corresponding aryldiazonium salts. Very recently, surface reactivity of carbons toward electrophilic halo-derivatives with long alkyl chains had been developed. Surface nucleophilicity of carbons was induced by their specific cathodic charge (at E < — 1.7 V in nonaqueous electrolytes) affecting the nano-crystallites (mainly graphite) contained in glassy carbons due to the mode of its manufacturing (high temperature carbonization of phenolic resins). This new paradigm of surface decoration was successfully applied using alkyl halides, carbon dioxide, dioxygen, sulfonyl chlorides etc. and proved efficient with allotropic varieties of carbon (in particular graphites and graphene).

General chemistry, physical chemistry, Chimie générale, chimie physique, Energy, Énergie, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Electrotechnique. Electroenergetique, Electrical engineering. Electrical power engineering, Matériel électrique divers, Various equipment and components, Condensateurs. Résistances. Filtres, Capacitors. Resistors. Filters, Acide sulfurique, Sulfuric acid, Sulfúrico ácido, Capacité électrique, Capacitance, Capacitancia, Chimie surface, Surface chemistry, Condensateur électrochimique, Electrolytic capacitor, Condensador electroquímico, Délaminage, Delamination, Delaminación, Insertion, Inserción, Matériau modifié, Modified material, Material modificado, Rayon X, X ray, Rayos X, Solution acide, Acidic solution, Solución ácida, Solution électrolyte, Electrolyte solution, Solución electrólito, Spectrométrie photoélectron, Photoelectron spectrometry, Espectrometría fotoelectrón, Structure 2 dimensions, Two dimensional structure, Estructura 2 dimensiones, Titane Carbure, Titanium Carbides, Titanio Carburo, Traitement surface, Surface treatment, Tratamiento superficie, Electrochemical capacitors, Two-dimensional materials, and XPS

The electrochemical behavior of Ti3C2, a two-dimensional titanium carbide from the MXene family, in H2SO4 electrolyte is reported. To demonstrate the effect of surface chemistry on capacitive performance, Ti3C2 was modified by delamination or intercalation treatments. Electrochemical testing revealed an increase in capacitance, which was attributed to oxygen-containing functional groups. An extraordinary high intercalation capacitance of 415 F·cm―3 at 5 A·g―1 was obtained from electrodes with a specific surface area of just 98 m2·gv―1. Values up to 520 F·cm―3 were recorded for delaminated MXene films at 2 mV·s―1. This study highlights that the behavior of materials from the large family of two-dimensional MXene can be tuned by suitable modification of their surface chemistry.

General chemistry, physical chemistry, Chimie générale, chimie physique, Energy, Énergie, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Electrotechnique. Electroenergetique, Electrical engineering. Electrical power engineering, Electroénergétique, Electrical power engineering, Conversion directe et accumulation d'énergie, Direct energy conversion and energy accumulation, Conversion électrochimique: piles et accumulateurs électrochimiques, piles à combustibles, Electrochemical conversion: primary and secondary batteries, fuel cells, Accumulateur électrochimique, Secondary cell, Acumulador electroquímico, Caractérisation, Characterization, Caracterización, Caractéristique électrique, Electrical characteristic, Característica eléctrica, Cathode, Cátodo, Cycle charge décharge, Discharge charge cycle, Ciclo carga descarga, Diffraction RX, X ray diffraction, Difracción RX, Lithium Oxyde, Lithium Oxides, Litio Óxido, Manganèse Oxyde, Manganese Oxides, Manganeso Óxido, Matériau électrode, Electrode material, Material electrodo, Microscopie électronique transmission, Transmission electron microscopy, Microscopía electrónica transmisión, Morphologie, Morphology, Morfología, Pentaoxyde de phosphore, Phosphorus oxide, Fósforo pentaóxido, Phosphore Oxyde, Phosphorus Oxides, Fósforo Óxido, Rayon X, X ray, Rayos X, Rendement courant, Current efficiency, Rendimiento corriente, Réaction gaz solide, Gas solid reaction, Reacción gas sólido, Spectrométrie IR, Infrared spectrometry, Espectrometría IR, Spectrométrie photoélectron, Photoelectron spectrometry, Espectrometría fotoelectrón, Structure lamellaire, Lamellar structure, Estructura lamelar, Structure surface, Surface structure, Estructura superficie, Traitement surface, Surface treatment, Tratamiento superficie, Traitement thermique, Heat treatment, Tratamiento térmico, Transformation Fourier, Fourier transformation, Transformación Fourier, Batterie lithium ion, Lithium ion batteries, FT IR, Cathode materials, Li-rich layered oxides, Lithium-ion batteries, P2O5 heat-treatment, and Surface modification

Rate capability and charge/discharge coulombic efficiency of Li-rich layered oxides was greatly improved by surface modification with P2O5 through a gas-solid reaction. The P2O5 treatment results in forming a uniform nanoscale coating layer of ionically conductive Li3PO4 and spinel-like material on Li-rich layered oxide particles. The resulting material delivers a charge/discharge coulombic efficiency of 90% compared with 81% of the pristine sample during the first cycle. The treated electrode also exhibits improved rate capability with a reversible capacity of 148 mAh g-1 at 4 C-rate vs. 269 mAh g-1 at 0.1 C-rate between 2.0 and 4.8 V.

General chemistry, physical chemistry, Chimie générale, chimie physique, Energy, Énergie, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Electrochimie, Electrochemistry, Etude des interfaces, Study of interfaces, Dépôt électrolytique, Electrodeposition, Métal transition, Transition metal, Metal transición, Amination, Aminación, Ammoniac liquide, Liquid ammonia, Amoníaco líquido, Bore, Boron, Boro, Diamant, Diamond, Diamante, Dépôt par oxydoréduction, Electroless plating, Depósito por oxidorreducción, Matériau dopé, Doped materials, Matériau modifié, Modified material, Material modificado, Microscopie électronique balayage, Scanning electron microscopy, Microscopía electrónica barrido, Morphologie, Morphology, Morfología, Mécanisme réaction, Reaction mechanism, Mecanismo reacción, Nanoparticule, Nanoparticle, Nanopartícula, Or, Gold, Oro, Persulfate, Persulfates, Rayon X, X ray, Rayos X, Réaction électrochimique, Electrochemical reaction, Reacción electroquímica, Spectrométrie photoélectron, Photoelectron spectrometry, Espectrometría fotoelectrón, Structure surface, Surface structure, Estructura superficie, Traitement surface, Surface treatment, Tratamiento superficie, BDD, Diamond films, Gold nanoparticles, and XPS

Diamond presents many interesting properties in terms of biocompatibility, chemical inertness and is attractive for applications notably in the biosensor field. The formation of amine functional groups at the diamond surface is of great interest for biomolecule's immobilization. In this work, we present for the first time, the electroless amination of diamond surfaces exposed to a liquid ammonia solution containing persulfate. Chemical surface modifications were followed by XPS analyses, while the distribution of amino-groups was studied by gold nanoparticles immobilization. This combined approach proved the growth of amino groups at the diamond surface during the electroless treatment.

General chemistry, physical chemistry, Chimie générale, chimie physique, Energy, Énergie, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Electrochimie, Electrochemistry, Electrodes: préparations et propriétés, Electrodes: preparations and properties, Autres électrodes, Other electrodes, Fer Composé organique, Iron Organic compounds, Hierro Compuesto orgánico, Acétonitrile, Acetonitrile, Acetonitrilo, Benzène(nitro), Carbone, Carbon, Carbono, Carboxylate, Carboxilato, Composé acétylénique, Acetylenic compound, Compuesto acetilénico, Composé aliphatique, Aliphatic compound, Compuesto alifático, Composé nitro, Nitro compound, Compuesto nitro, Composé éthylénique, Ethylenic compound, Compuesto etilénico, Electrode, Electrodes, Electrodo, Etat vitreux, Glassy state, Estado vitreo, Ferrocène, Ferrocene, Fonctionnalisation, Functionalization, Funciónalización, Métallocène, Metallocene, Metaloceno, Oxydation, Oxidation, Oxidación, Réaction Heck, Heck reaction, Reacción Heck, Réaction électrochimique, Electrochemical reaction, Reacción electroquímica, Solvant organique, Organic solvent, Solvente orgánico, Traitement surface, Surface treatment, Tratamiento superficie, Ammonium(tétrabutyl) hexafluoroborate, Chimie clic, Click chemistry, Greffage électrochimique, Electrochemical grafting, Pent-4-ynoate, Pent-4-énoate, Carbon surface, Carboxylates, Grafting, Modified electrodes, and Non-Kolbe

The covalent modification of glassy carbon electrodes by oxidation of unsaturated aliphatic carboxylates is reported in this work. It is shown that the presence of π-bonds on the hydrocarbon structure is essential to develop the grafting process, which does not occurs with totally saturated carboxylates. In this way, the glassy carbon surface modification with aliphatic chains containing alkene and alkyne groups was performed and the presence of such groups was demonstrated through a Heck and a Click reaction, allowing respectively a further functionalization with nitrobenzene and ferrocene groups.

General chemistry, physical chemistry, Chimie générale, chimie physique, Energy, Énergie, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Electrochimie, Electrochemistry, Electrodes: préparations et propriétés, Electrodes: preparations and properties, Autres électrodes, Other electrodes, Fer Composé organique, Iron Organic compounds, Hierro Compuesto orgánico, Platinoïde, Platinoid, Platinoide, Alkylation, Alquilación, Benzène(bromo), Carbone, Carbon, Carbono, Catalyse redox, Redox catalysis, Catálisis redox, DMF, N,N-Dimethylformamide, Dimetilformamida, Electrocatalyse, Electrocatalysis, Electrocatálisis, Electrode, Electrodes, Electrodo, Etat vitreux, Glassy state, Estado vitreo, Graphène, Graphene, Matériau composite, Composite material, Material compuesto, Matériau modifié, Modified material, Material modificado, Microscopie électronique balayage, Scanning electron microscopy, Microscopía electrónica barrido, Morphologie, Morphology, Morfología, Métal transition, Transition metal, Metal transición, Métal zérovalent, Zerovalent metal, Metal cerovalente, Métallocène, Metallocene, Metaloceno, Palladium, Paladio, Réaction électrochimique, Electrochemical reaction, Reacción electroquímica, Réduction chimique, Chemical reduction, Reducción química, Solvant organique, Organic solvent, Solvente orgánico, Structure surface, Surface structure, Estructura superficie, Traitement surface, Surface treatment, Tratamiento superficie, Ammonium(tétrabutyl) tétrafluoroborate, Ferrocène dérivé, Greffage électrochimique, Electrochemical grafting, Alkyl radical trapping, Chemically modified electrodes, Ferrocene grafting, and Graphene electrodes

When glassy carbon (GC) is mechanically covered with micrometric layers of graphene, the reduction of primary alkyl halides (RX) can shift to the catalytic mode due to the fact that cathodically charged graphene may act as a redox reducing agent triggering a classical redox catalytic process with a moderate gain (<0.2 V) in potential. Alternatively, the injection of very small amounts of transition metals (not only Pd, but also Au, Ag or Pt) at zero-valent state into the graphene layer may induce catalytic reduction of RIs and RBrs that allows the formation of free radicals R● and their concomitant grafting, not only at the GC/graphene interface but also in bulk graphene that plays the role of a three-dimensional radical scavenger. Therefore, by use of this simple process, GC/graphene layers could be converted into a 3D active interface. In order to quantify the global grafting/insertion of R●, ferrocene and aryl probes (Fc-n-alkyl-1 and pyrene-CH2-Br) were used, attesting to significant modification of the interface. Thus, for the first time, a bulky graphene-ferrocene layer (a redox system fully usable as a 3D modified electrode) was built. This model could quite hopefully be envisaged for electrochemically incorporating many other redox centers in graphene within the potential range of - 2 V to +1 V vs. Ag/AgCl.

General chemistry, physical chemistry, Chimie générale, chimie physique, Energy, Énergie, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Electrochimie, Electrochemistry, Electrodes: préparations et propriétés, Electrodes: preparations and properties, Autres électrodes, Other electrodes, Métal transition, Transition metal, Metal transición, Argent, Silver, Plata, Codépôt, Codeposition, Codeposición, Diffraction RX, X ray diffraction, Difracción RX, Diffraction électron sélection aire, SAED, Dépôt électrophorétique, Electrophoretic deposition, Depósito electroforético, Electrode ITO, Indium tin oxide electrode, Electrodo ITO, Electrode optiquement transparente, Optically transparent electrode, Electrodo ópticamente transparente, Matériau poreux, Porous material, Material poroso, Microscopie électronique balayage, Scanning electron microscopy, Microscopía electrónica barrido, Microscopie électronique transmission, Transmission electron microscopy, Microscopía electrónica transmisión, Morphologie, Morphology, Morfología, Mésoporosité, Mesoporosity, Mesoporosidad, Méthode ablation laser, Laser ablation technique, Nanoparticule, Nanoparticle, Nanopartícula, Or, Gold, Oro, Particule colloïdale, Colloid particle, Partícula coloidal, Particule sphérique, Spherical particle, Partícula esférica, Spectrométrie RX dispersion énergie, Energy-dispersive X-ray spectrometry, Espectrometría RX dispersión energía, Spectrométrie SERS, Surface Enhanced Raman Spectrometry, Espectrometría SERS, Structure surface, Surface structure, Estructura superficie, Traitement surface, Surface treatment, Tratamiento superficie, Au nanoparticles, Electrophoresis deposition, Mesoporous film, and Selective etching

A simple and facile strategy is presented to fabricate mesoporous Au spherical nanoparticle films based on the combination of co-electrophoresis deposition in the mixed colloidal solutions of Au and Ag and selective etching of the Ag nanoparticles which act as a sacrificial metal. The film is homogeneous in the macroscale but with numerous nanoscaled pores. The film configuration can be easily tuned by the size of Au colloidal nanoparticles and the amount of Ag colloidal solution mixed. Importantly, such structured mesoporous film exhibits strong surface-enhanced Raman scattering activity with good reproducibility and repeatability. Additionally, this study provides a novel method for the controllable construction of other mesoporous films from simple metals to multicomponent hybrids, by using nanoparticles as building blocks.

General chemistry, physical chemistry, Chimie générale, chimie physique, Energy, Énergie, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Electrotechnique. Electroenergetique, Electrical engineering. Electrical power engineering, Electroénergétique, Electrical power engineering, Conversion directe et accumulation d'énergie, Direct energy conversion and energy accumulation, Conversion électrochimique: piles et accumulateurs électrochimiques, piles à combustibles, Electrochemical conversion: primary and secondary batteries, fuel cells, Accumulateur électrochimique, Secondary cell, Acumulador electroquímico, Aire surface spécifique, Specific surface area, Anode, Anodo, Attaque chimique, Chemical etching, Ataque químico, Caractéristique électrique, Electrical characteristic, Característica eléctrica, Carbonisation, Carbonization, Carbonización, Couche autoportée, Free-standing film, Cycle charge décharge, Discharge charge cycle, Ciclo carga descarga, Electrofilage, Electrospinning, Electrohilado, Fibre carbone, Carbon fiber, Fibra carbón, Imide polymère, Polyimide, Imida polímero, Matériau poreux, Porous material, Material poroso, Matériau électrode, Electrode material, Material electrodo, Microscopie électronique balayage, Scanning electron microscopy, Microscopía electrónica barrido, Microscopie électronique transmission, Transmission electron microscopy, Microscopía electrónica transmisión, Morphologie, Morphology, Morfología, Nanostructure, Nanoestructura, Propriété surface, Surface properties, Propiedad superficie, Préparation, Preparation, Preparación, Silice, Silica, Sílice, Structure surface, Surface structure, Estructura superficie, Traitement surface, Surface treatment, Tratamiento superficie, Batterie lithium ion, Lithium ion batteries, Nanofibre carbone, Electrospining, Lithium-ion battery, and Porous carbon nanofiber

Highly porous carbon nanofibers (PCNFs) were prepared by electrospining polyimide and sacrificial SiO2 nanoparticles, along with the subsequent carbonization and post-etching. The PCNFs exhibited interconnected nanofibrous morphology with large specific surface area (950 m2 g―1) and well-developed microporous structure. The electrochemical performance measurements indicated that the PCNFs as self-standing anodes of rechargeable lithium―ion batteries (LIBs) showed outstanding lithium―ion storage capacity (730 mAh g―1), good cycling stability and superior rate capability. These intriguing characteristics make the PCNFs materials as promising anode candidates for high-performance LIBs.

General chemistry, physical chemistry, Chimie générale, chimie physique, Energy, Énergie, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Electrochimie, Electrochemistry, Généralités, General, Acide sulfurique, Sulfuric acid, Sulfúrico ácido, Appareillage, Instrumentation, Instrumentación, Attaque chimique, Chemical etching, Ataque químico, Cystine, Cistina, Electrode, Electrodes, Electrodo, Gallium Arséniure, Gallium Arsenides, Galio Arseniuro, Microscopie force atomique, Atomic force microscopy, Microscopía fuerza atómica, Microscopie électronique balayage, Scanning electron microscopy, Microscopía electrónica barrido, Microusinage, Micromachining, Micromaquinado, Morphologie, Morphology, Morfología, Méthacrylate de méthyle polymère, Methyl methacrylate polymer, Metacrilato de metilo polímero, Semiconducteur type n, n type semiconductor, Semiconductor tipo n, Sodium Bromure, Sodium Bromides, Sodio Bromuro, Solution acide, Acidic solution, Solución ácida, Structure surface, Surface structure, Estructura superficie, Traitement surface, Surface treatment, Tratamiento superficie, Trame microlentille, Microlens arrays, Red microlente, Usinage électrochimique, Electrochemical machining, Mecanizado electroquímico, Technique CELT, Confined etchant layer technique, CELT, Electrochemical instrument, Electrochemical micromachining, and n-GaAs microlens array

High-quality products come from high-quality instrument. We present here an optimized instrument for electrochemical micromachining, in which a granite bridge base, a macro-micro dual driven positioning stage and a force-displacement sensing module are combined to promote dramatically the tool-workpiece alignment, in-situ monitoring and product quality. As a testing experiment, a polymethylmethacrylate (PMMA) microlens array with a diameter of 110 μm and a height of 3.5 μm has been transferred successfully onto the surface of an n-GaAs wafer by the confined etchant layer technique (CELT). The machining tolerance is about 3.4 nm and the surface roughness is lower than 8.0 nm. Moreover, the presented techniques have significance in the precise electrochemical instruments for not only micromachining but also scanning electrochemical probe techniques.

General chemistry, physical chemistry, Chimie générale, chimie physique, Energy, Énergie, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Electrochimie, Electrochemistry, Electrodes: préparations et propriétés, Electrodes: preparations and properties, Autres électrodes, Other electrodes, Arylation, Arilación, Carbone, Carbon, Carbono, Cation organique, Organic cation, Catión orgánico, Composé du diazonium, Diazonium compounds, Diazonio compuesto, Couple redox, Redox couple, Pareja redox, Electrode, Electrodes, Electrodo, Etat vitreux, Glassy state, Estado vitreo, In situ, Liquide ionique, Ionic liquid, Líquido iónico, Réaction électrochimique, Electrochemical reaction, Reacción electroquímica, Réaction électrode, Electrode reaction, Reacción electrodo, Réduction chimique, Chemical reduction, Reducción química, Sodium Nitrite, Sodium Nitrites, Sodio Nitrito, Solution acide, Acidic solution, Solución ácida, Traitement surface, Surface treatment, Tratamiento superficie, Transfert électron, Electron transfer, Transferencia electrón, Voltammétrie cyclique, Cyclic voltammetry, Voltametría cíclica, Greffage électrochimique, Electrochemical grafting, Imidazolium(1-méthyl-3-[4-nitrophénéthyl]) amidure(bis[trifluoromésyl]), Anion exchange, Aryl imidazolium, In situ diazonium, and Surface modification

Electrochemical reduction on carbon electrode of 1-nitrophenylethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ionic liquid in acidic media containing sodium nitrite has been investigated. As a consequence, the corresponding diazonium was generated in situ in the vicinity of the electrode, then electroreduced onto the electrode surface inducing the attachment of phenyl imidazolium groups. The electrochemical behavior of the modified electrodes toward various redox probes was investigated. As a result, the attached layer acts as barrier against the electron transfer when using neutral and positively charged redox probes while, electron transfer transparency is obtained when using negatively charged redox species. The positively charged imidazolium attached onto the surface exhibits a selective electron transfer toward redox probe molecules. Finally, the capability to perform anion exchange within the immobilized layer was evaluated by incorporating a redox active counter anion.

General chemistry, physical chemistry, Chimie générale, chimie physique, Energy, Énergie, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie analytique, Analytical chemistry, Généralités, appareillage, General, instrumentation, Alumine, Alumina, Alúmina, Anodisation, Anodizing, Anodización, Capteur humidité, Moisture sensor, Sensor humedad, Diagramme Nyquist, Nyquist diagram, Diagrama Nyquist, Diffraction RX, X ray diffraction, Difracción RX, Microscopie électronique balayage, Scanning electron microscopy, Microscopía electrónica barrido, Morphologie, Morphology, Morfología, Oxydation, Oxidation, Oxidación, Réaction électrochimique, Electrochemical reaction, Reacción electroquímica, Schéma équivalent, Equivalent circuit, Esquema equivalente, Sensibilité, Sensitivity, Sensibilidad, Spectrométrie impédance électrochimique, Electrochemical impedance spectroscopy, Stabilité, Stability, Estabilidad, Structure surface, Surface structure, Estructura superficie, Traitement surface, Surface treatment, Tratamiento superficie, Al2O3, Humidity sensor, and Micro-arc oxidation

Humidity sensor based on thin micro-arc oxidation alumina (MOA) film was fabricated by a transient self-feedback control (TSFC) technique for the first time. The MOA film consisted of a polycrystalline nature of α and γ-Al2O3 phases, while high surface/volume ratio led to remarkable adsorption of the MOA film. Moreover, the humidity performance of the MOA sensor indicated good sensitivity of 8045.55 at 98% RH. Fast response and recovery times of the MOA sensor were 90 s and 30 s, respectively, at 20 °C and 1000 Hz. Exposing the MOA sensor to different humidities for longer durations indicated an excellent stability due to the α-Al2O3 phase in the MOA film. The mechanism in the sensor, to humidity, was explained by using equivalent circuits of (RC) and (C(RZ)). In the low RH range, the process was mainly dominated by the migration of protons through the adsorbed water molecule layer on the surface of the MOA film; while, in the high RH range, the process was due to the faster diffusion of protons in the single or multiple layers that were formed on the materials surface.

General chemistry, physical chemistry, Chimie générale, chimie physique, Energy, Énergie, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Electrochimie, Electrochemistry, Généralités, General, Métal transition, Transition metal, Metal transición, Détecteur électrochimique, Electrochemical detector, Detector electroquímico, Formation motif, Patterning, Formacíon motivo, Hydrogel, Hidrogel, Lithographie, Lithography, Litografía, Microélectrode, Microelectrode, Microeléctrodo, Or, Gold, Oro, Réseau (arrangement), Array, Red, Technique rapide, Rapid technique, Técnica rápida, Traitement surface, Surface treatment, Tratamiento superficie, Voltammétrie, Voltammetry, Voltametría, Au microband pattern, Hydrogel etching, Microelectrode arrays, and Voltammetric detection

In this communication, we describe a facile technique to reproducibly fabricate regular Au microband electrode arrays with one kind of soft lithography, i.e. hydrogel etching. Au microband arrays were formed by closely contacting the micropatterned hydrogel stamp soaked with a solution of water-based etching solution with Au film sputtered on a glassy chip. Scanning electron microscopy results demonstrate that the formed Au microband arrays are uniform and had good resolution. Electrochemical results show that the Au microband arrays exhibit fast mass transport and low charging current, suggesting that the Au microband arrays fabricated with soft lithography behave like a microelectrode array (MEA). These electrochemical properties of the Au band MEA essentially made it very attractive for sensitive electroanalysis, which was illustrated by voltammetric determination of ferricyanide and dopamine down to submicromolar level.

General chemistry, physical chemistry, Chimie générale, chimie physique, Energy, Énergie, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Electrochimie, Electrochemistry, Electrodes: préparations et propriétés, Electrodes: preparations and properties, Autres électrodes, Other electrodes, Carbonate organique, Organic carbonate, Carbonato orgánico, Carbone, Carbon, Carbono, Chimie surface, Surface chemistry, Dérivé de l'acétophénone, Acetophenone derivatives, Acetofenona derivado, Electrode, Electrodes, Electrodo, Enolisation, Enolization, Enolización, Etat vitreux, Glassy state, Estado vitreo, Halogénocétone, Haloketone, Halocetona, Matériau modifié, Modified material, Material modificado, Réaction électrochimique, Electrochemical reaction, Reacción electroquímica, Réduction chimique, Chemical reduction, Reducción química, Solvant aprotique, Aprotic solvent, Solvente aprótico, Traitement surface, Surface treatment, Tratamiento superficie, 1,3-Dioxolan-2-one(méthyl), Ammonium(tétraalkyl) iodure, Enol radical grafting, Glassy carbon, Modified electrodes, and ω-Bromomethylarylketones

The cathodic reduction of ω-bromomethylarylketones in aprotic organic solvents (such as propylene carbonate) containing tetraalkylammonium iodides achieved at smooth glassy carbon (GC) permits through a selective one-electron reduction, the scission of the C-Br bond. Quite unexpectedly, the free radical thus formed is prior attached to the carbon surface in its enolic form (GC―O―(Ar)C=CH2). Successive radical addition processes may lead to a redox polymer based on the one-electron oxidation of enol ethers. The average superficial enol concentration at the carbon surface (found to be about 2.5 x 10―8 mol cm―2) was assessed by the halogen index (iodine or bromine) via halogen addition to the double bonds followed by the micro-coulometric reduction of the resulting vicinal di-halo compounds.

General chemistry, physical chemistry, Chimie générale, chimie physique, Energy, Énergie, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Electrochimie, Electrochemistry, Généralités, General, Enzyme, Enzima, Métal transition Complexe, Transition metal Complexes, Metal transición Complejo, Métal transition, Transition metal, Metal transición, Oxidoreductases, Anion minéral, Inorganic anion, Anión inorgánico, Azide, Organic azide, Azida orgánica, Complexe aqua, Aqua complex, Complejo aqua, Coordinat organique, Organic ligand, Ligando orgánico, Couche autoassemblée, Self-assembled layer, Capa autoensamblada, Couche monomoléculaire, Monolayer, Capa monomolecular, Cuivre Complexe, Copper Complexes, Cobre Complejo, Degré recouvrement, Coverage rate, Grado recubrimiento, Dérivé de la pyridine, Pyridine derivatives, Piridina derivado, Electrocatalyse, Electrocatalysis, Electrocatálisis, Matériau modifié, Modified material, Material modificado, Modèle, Models, Modelo, Nitrite reductase, Nitrite, Nitrites, Nitrito, Or, Gold, Oro, Réaction biomimétique, Biomimetic reaction, Reacción biomimética, Réaction électrochimique, Electrochemical reaction, Reacción electroquímica, Réduction chimique, Chemical reduction, Reducción química, Solution acide, Acidic solution, Solución ácida, Traitement surface, Surface treatment, Tratamiento superficie, Chimie clic, Click chemistry, Greffage électrochimique, Electrochemical grafting, Click, Copper nitrite reductase model, and Self-assembled monolayers

A biomimetic copper complex has been attached as SAMs onto an azidoundecanethiol-modified gold electrode by the self-induced electroclick procedure. The immobilized complex electrocatalyzes efficiently the reduction of nitrite ions in an acidic medium. The in-situ control of the surface coverage during the grafting process by the electroclick approach has been exploited to rationalize the influence of surface concentration on the electrocatalytic properties of the immobilized Cu complex. The voltammetric analysis shows an enhancement of the catalytic rate when the surface coverage is decreased, as a consequence of steric and electronic effects.

General chemistry, physical chemistry, Chimie générale, chimie physique, Energy, Énergie, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Electrochimie, Electrochemistry, Electrodes: préparations et propriétés, Electrodes: preparations and properties, Autres électrodes, Other electrodes, Carbonate organique, Organic carbonate, Carbonato orgánico, Carbone, Carbon, Carbono, Electrode, Electrodes, Electrodo, Etat vitreux, Glassy state, Estado vitreo, Mécanisme radicalaire, Radical mechanism, Mecanismo radicalar, Quinone, Quinona, Réaction électrochimique, Electrochemical reaction, Reacción electroquímica, Réduction chimique, Chemical reduction, Reducción química, Solvant organique, Organic solvent, Solvente orgánico, Traitement surface, Surface treatment, Tratamiento superficie, 1,3-Dioxolan-2-one(méthyl), Ammonium(tétrabutyl) iodure, Antraquinone(2-bromométhyl), Greffage électrochimique, Electrochemical grafting, 9,10-Anthraquinone, Immobilization, and Radical grafting

We report here a new and very efficient method for the coverage of different carbon materials with 9,10-anthraquinone attached via a methylene linker. The method is based on one-electron reduction of 2-(bromomethyl)anthraquinone (AQ-CH2-Br) to a free radical AQ―CH2• which was readily achieved using propylene carbonate (PC) as solvent containing tetrabutylammonium iodide. This way, the radical AQ―CH2• adds to the abovementioned carbons forming very stable and dense covalently bound anhraquinonyl methane layers (Γ≈2×10―9 mol cm―2). The grafting could be performed by constant potential electrolyses (q<0.5× 10―3 C mm―2).

General chemistry, physical chemistry, Chimie générale, chimie physique, Energy, Énergie, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Electrochimie, Electrochemistry, Electrodes: préparations et propriétés, Electrodes: preparations and properties, Autres électrodes, Other electrodes, Acétonitrile, Acetonitrile, Acetonitrilo, Carbone, Carbon, Carbono, Cathode, Cátodo, DMF, N,N-Dimethylformamide, Dimetilformamida, Electrode, Electrodes, Electrodo, Electrophilicité, Electrophilicity, Electrofilicidad, Etat vitreux, Glassy state, Estado vitreo, Fonctionnalisation, Functionalization, Funciónalización, Hydrocarbure iodé, Iodocarbon, Hidrocarburo iodado, Hydroperoxyde, Hydroperoxide, Hidroperóxido, Oxygène, Oxygen, Oxígeno, Peroxydation, Peroxidation, Peroxidación, Peroxyde organique, Organic peroxide, Peróxido orgánico, Solvant organique, Organic solvent, Solvente orgánico, Solvant polaire, Polar solvent, Disolvente polar, Traitement surface, Surface treatment, Tratamiento superficie, Alcane(iodo), Ammonium(tétraalkyl) tétrafluoroborate, Carbon cathodes, Carbon functionalization, Hydroperoxides, Oxygen grafting, and Peroxides

The reduction of oxygen of the air at carbon electrodes in organic aprotic polar solvents in the presence of organic electrophiles such as alkyl iodides may reveal the formation of films of surface-attached alkyl peroxides. Electrochemical charge of carbons (glassy carbon, graphite, industrial coke) in the presence of tetraalkylammonium salt TAAX permits the building of poly-nucleophilic materials that may spontaneously react with air during the work up. This way, a TAA+ hydroperoxydate layer immobilized at the solid surface can be obtained. The existence of such layers is supported by the reaction with a large number of organic electrophiles in order to generate attached organic peroxides capable (i) to be cleaved (two-electron scission of the O―O bond) or (ii) to obtain by grafting of π-acceptors and/or π-donors, specific redox responses at those modified surfaces. Such modification procedure (essentially green: electrolytic solutions are totally re-usable with the main reagent being air) is expected to yield a material easily transformed into a stable poly-hydroxylated solid. At this stage, a large panel of simple chemical transformations can be imagined from classical organic and inorganic chemistry.

General chemistry, physical chemistry, Chimie générale, chimie physique, Energy, Énergie, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Electrochimie, Electrochemistry, Généralités, General, Métal transition, Transition metal, Metal transición, Platinoïde, Platinoid, Platinoide, Activité catalytique, Catalyst activity, Actividad catalítica, Adsorption, Adsorción, Bismuth, Bismuto, Electrode, Electrodes, Electrodo, Glycérol, Glycerol, Glicerol, Matériau modifié, Modified material, Material modificado, Microscopie électronique transmission, Transmission electron microscopy, Microscopía electrónica transmisión, Morphologie, Morphology, Morfología, Nanosphère, Nanosphere, Nanosfera, Nanostructure, Nanoestructura, Or, Gold, Oro, Orientation cristalline, Crystal orientation, Orientación cristalina, Oxydation, Oxidation, Oxidación, Palladium, Paladio, Réaction électrochimique, Electrochemical reaction, Reacción electroquímica, Structure surface, Surface structure, Estructura superficie, Traitement surface, Surface treatment, Tratamiento superficie, Adatoms, Glycerol oxidation, Nanocubes, and Nanospheres

Syntheses, surface modification by bismuth adatoms and activity towards glycerol electro-oxidation of preferentially-shaped Pd nanoparticles are described. High activity of {100} surface nanodomains is demonstrated, as well as changes in activity and selectivity induced by the presence of Bi adatoms.