Publications de Hubert Girault

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This tutorial review aims at presenting the concept of electrolysis with a bipolar electrode stack reactor. This design approach is commonly used industrially both for alkaline and PEM water electrolysis for hydrogen production. The goal here is notably to present and discuss the concept of shunt, parasitic and reverse currents, and to show how they affect the faradaic and the energy efficiencies of the electrolysis. These electrolyser design issues largely explain the difficulty to build very large industr

Photo-ionic cells are a simple and scalable concept for direct solar energy storage, where the redox fuels produced by the photoreaction are separated in different phases to prevent recombination. The presence of chaotropic agents such as urea, that break ...

Scanning electrochemical microscopy potentiometric determination of local hydrogen concentration and its flux next to the liquid|liquid interface was demonstrated. This method is based on the shift of open circuit potential of Pt-based reversible hydrogen ...

A solar energy conversion concept based on the photo-induced separation of a pair of redox species in a biphasic liquid cell is presented. The redox pair is subsequently discharged in an electrochemical flow cell to generate electricity. To illustrate this ...

The size dependence of electron-phonon coupling rate has been investigated by femtosecond transient absorption spectroscopy for gold nanoparticles (NPs) wrapped in a shell of sulfate with diameter varying from 1.7 to 9.2 nm. Broad-band spectroscopy gives a ...

We report the mapping of biocatalytically active surfaces, particularly on an express search for optimal immobilization conditions of the enzyme lactate oxidase by means of scanning electrochemical microscopy (SECM). With this aim, soft stylus SECM probes ...

Investigating and understanding dynamic biofilm growth mechanisms is challenging, often because state-of-the-art optical characterization tools provide limited information. Micrometric electrochemical imaging of Escherichia coli biofilms using Soft-Probe-S ...

The photochemical reactivity of osmocene in a biphasic water-organic solvent system has been investigated to probe its water splitting properties. The photoreduction of aqueous protons to hydrogen under anaerobic conditions induced by osmocene dissolved in ...

A new approach to assess the orthogonality of two-dimensional (2-D) separation systems based on conditional entropy is developed. It considers the quantitative distribution of peaks in the entire separation space such that the orthogonality obtained is independent of the number of peaks observed for each separation technique. Therefore, it can be used to compare the orthogonality of different 2-D separation protocols for a given sample. Herein, the developed method has been employed to estimate the orthogon

Copper-b-amyloid 16 (Aβ16) complexes were investigated by electrospray ionization mass spectrometry (ESI-MS). Copper(I) and (II) complexes were formed on-line in a microchip electrospray emitter by using a sacrificial copper electrode as the anode in posit ...

Gold nanoparticle (Au NP) mirrors, that exhibit both high reflectance and electrical conductance, were self-assembled at a [heptane + 1,2-dichloroethane]/water liquid/liquid interface. The highest reflectance, as observed experimentally and confirmed by fi ...

The redox properties of metallic nanoparticles are discussed, in particular the relationships between excess charge, size and the Fermi level of the electrons. The redox potentials are derived using simple electrostatic models to provide a straightforward ...

For effective monitoring and prevention of the food allergy, one of the emerging health problems nowadays, existing diagnostic procedures and allergen detection techniques are constantly improved. Meanwhile, new methods are also developed, and more and mor ...

RATIONALE: The perfume market is growing significantly, and it is easy to find imitative fragrances of probably all types of perfume. Such imitative fragrances are usually of lower quality than the authentic ones, creating a possible threat for perfume com ...

A target plate for enhanced matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) analysis of intact biological entities. The target plate comprises an electrically conductive substrate (1) covered at least partially with immobilised pho ...

The photosensitized reduction of carbon dioxide by the molecular catalyst [Ru(bpy)2(CO)L] is studied in a biphasic liquid-condensed gas system. Increasing pressure is shown to enhance the initial production rate and turnover number of the catalyst before d ...

We present soft spider array for gentle contact mode scanning electrochemical microscopy (SECM) imaging of tissues. The spider array contains up to eight completely individual, parallel, and flexible carbon microelectrodes designed to scan square centimeter sized areas on reasonable time scales while avoiding sample aging and electrode fouling. The contact mode enables the scanning of largely curved samples at a constant distance. The spider array is applied for the SECM imaging of the distribution of certa

Finite element simulations were used to investigate the effect of a smooth variation of permittivity across a polarized liquid/liquid interface on the differential capacitance. The results show that a relative permittivity profile can account for the varia ...

Currently two types of chip systems are used in conjunction with MS: out-of-plane devices, where hundreds of nozzles, nanospray emitters are integrated onto a single silicon substrate from which electrospray is established perpendicular to the substrate, a ...

Here, we report hydrogen peroxide generation at 2-nitrophenyloctyl ether (NPOE)-water interface with decamethylferrocene as an electron donor. The progress of this reaction was detected by the observation of color change of the organic and aqueous phases i ...

Hubert Girault

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Bipolar plates in water electrolysis stacks: understanding basics and electrochemical aspects impacting the energy efficiency during operation

Chaotropic Agents Boosting the Performance of Photo-ionic Cells

Scanning electrochemical microscopy determination of hydrogen flux at liquid|liquid interface with potentiometric probe

Photo-Ionic Cells: Two Solutions to Store Solar Energy and Generate Electricity on Demand

Size Dependence of Investigations of Hot Electron Cooling Dynamincs in Metal/Adsorbates Nanoparticles

Rapid optimisation of a lactate biosensor design using soft probes scanning electrochemical microscopy

Soft-probe-scanning electrochemical microscopy reveals electrochemical surface reactivity of E. coli biofilms

Biphasic water splitting by osmocene

Orthogonality of Two-Dimensional Separations Based on Conditional Entropy

Copper(I) and copper(II) binding to β-amyloid 16 (Aβ16) studied by electrospray ionization mass spectrometry

Conductive Gold Nanoparticle Mirrors at Liquid/Liquid Interfaces

Charging and Discharging at the Nanoscale: Fermi Level Equilibration of Metallic Nanoparticles

Bioanalytical methods for food allergy diagnosis, allergen detection and new allergen discovery

Electrostatic-spray ionization mass spectrometry sniffing for perfume fingerprinting

Maldi device and methods of preparation and use thereof

Photoreduction of CO2 Using [Ru(bpy)2(CO)L]n+ Catalysts in Biphasic Solution/Supercritical CO2 Systems

Soft Probe Scanning Electrochemical Microscopy with Spider Array for Visualizing Biomarkers and Redox Active Proteins in Animal Tissues

Differential capacitance of liquid/liquid interfaces of finite thicknesses: a finite element study

Chip electrospray mass spectrometry for carbohydrate analysis

H2O2 generation at carbon paste electrode with decamethylferrocene solution in 2-nitrophenyloctyl ether as a binder. The catalytic effect of MoS2 particles