Publications by authors named "Marie-Anne Dourges"

Article Synopsis
  • A manganese-cobalt asbolane material was synthesized from birnessite using low-temperature cationic exchange with cobalt nitrate, enabling a high active mass loading for use in supercapacitors.
  • The material features a unique structure with MnO-type slabs and Co(OH) islands, confirmed through electronic transmission microscopy, showing two interlocking hexagonal sublattices.
  • Electrochemical tests demonstrated impressive capacitance of up to 180 F g, revealing effective charge storage mechanisms synergizing the properties of both components, along with promising long-term performance durability.
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High internal phase emulsions (HIPEs) have templated self-standing porous carbonaceous materials (carboHIPEs) while employing Kraft Black Liquor, a paper milling industry byproduct, as a carbon precursor source. As such, the starting emulsion has been prepared through a laboratory-made homogenizer, while native materials have been characterized at various length scales either with Raman spectrometry, X-ray diffraction (XRD), mercury intrusion porosimetry, and nitrogen absorption. After thermal carbonization, specific surface areas ranging from ∼600 m g to 1500 m g have been reached while maintaining a monolithic character.

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In the energy storage field, an electrode material must possess both good ionic and electronic conductivities to perform well, especially when high power is needed. In this context, the development of composite electrode materials combining an electrochemically active and good ionic conductor phase with an electronic conductor appears as a perfectly adapted approach to generate a synergetic effect and optimize the energy storage performance. In this work, three layered MnO phases with various morphologies (veils, nanoplatelets and microplatelets) were combined with electronic conductor cobalt oxyhydroxides with different platelet sizes (∼20 nm 70 nm wide), to synthesize 6 different composites by exfoliation and restacking processes.

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Alkylation of aromatic hydrocarbons is among the most industrially important reactions, employing acid catalysts such as AlCl, HSO, HF, or HPO. However, these catalysts present severe drawbacks, such as low selectivity and high corrosiveness. Taking advantage of the intrinsic high acid strength and Lewis and Brønsted acidity of niobium oxide, we have designed the first series of NbO-SiO(HIPE) monolithic catalysts bearing multiscale porosity through the integration of a sol-gel process and the physical chemistry of complex fluids.

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A new straightforward synthetic strategy has been elaborated to achieve star-shaped triazatrinaphthylene and, for the first time, triazatrianthrylene derivatives. Their solution- and solid-state properties were thoroughly characterized by cyclic voltammetry, UV-vis absorption spectroscopy, X-ray diffraction, and density functional theory calculations. Original hexagonal molecular arrangements were found in the crystal phase, which opens a new pathway for designing materials with improved three-dimensional charge-transport properties.

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Nanostructuration is one of the most promising strategies to develop performant electrode materials for energy storage devices, such as hybrid supercapacitors. In this work, we studied the influence of precipitation medium and the use of a series of 1-alkyl-3-methylimidazolium bromide ionic liquids for the nanostructuration of β(III) cobalt oxyhydroxides. Then, the effect of the nanostructuration and the impact of the different ionic liquids used during synthesis were investigated in terms of energy storage performances.

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Increased levels of nitrate (NO) in the environment can be detrimental to human health. Herein, we report a robust, cost-effective, and scalable, hybrid material-based colorimetric/luminescent sensor technology for rapid, selective, sensitive, and interference-free NO detection. These hybrid materials are based on a square-planar platinum(II) salt [Pt(tpy)Cl]PF (tpy = 2,2';6',2″-terpyridine) supported on mesoporous silica.

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Carbon from biomass as an active material for supercapacitor electrodes has attracted much interest due to its environmental soundness, abundance, and porous nature. In this context, activated carbon prepared from coconut shells a simple activation process (water or steam as activation agents) was used as an active material in electrodes for eco-friendly supercapacitors. X-ray diffraction (XRD), Raman spectroscopy, conductivity, scanning electron microscopy (SEM), N sorption and thermogravimetry coupled to mass spectrometry (TGA-MS) studies revealed that activated carbon produced by this approach exhibit a graphitic phase, a high surface area, and large pore volume.

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Magnets derived from inorganic materials (e.g., oxides, rare-earth-based, and intermetallic compounds) are key components of modern technological applications.

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In this work, we report a convenient method of grafting non-leachable bioactive amine functions onto the surface of bacterial cellulose (BC) nanofibrils, via a simple silylation treatment in water. Two different silylation protocols, involving different solvents and post-treatments were envisaged and compared, using 3-aminopropyl-trimethoxysilane (APS) and (2-aminoethyl)-3-aminopropyl-trimethoxysilane (AEAPS) as silylating agents. In aqueous and controlled conditions, water-leaching resistant amino functions could be successfully introduced into BC, via a simple freeze-drying process.

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This paper reports on an innovative and efficient approach based on the use of ionic liquids to govern the nano-structuration of HCoO, in order to optimize the porosity and enhance the ionic diffusion through the electrode materials. In this work, we show that (1-pentyl-3-methyl-imidazolium bromide (PMIMBr) and 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF)) ionic liquids (ILs) used as templates during the synthesis orientate the nanoparticle aggregation which leads to increase of the porosity and the average pore size of the electrode material. It is also demonstrated that the ILs are strongly bonded to the HCoO surface, leading to surface functionalized HCoO materials, also called nanohybrids.

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Non-thermal atmospheric plasma of the gliding arc type was used as a tool for goethite-on-biochar hybrid material preparation. Biochars were first prepared by carbonizing raffia bamboo (the leafstalk of raffia palm) pith at 300 °C (BC3), 500 °C (BC5) and 700 °C (BC7). A suspension of each biochar in Fe aqueous solution was then exposed to a plasma discharge burning in humid air.

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Several stable non-aqueous apolar-in-polar medium internal phase emulsions (MIPEs) containing divinyl adipate and pentaerythritol in the continuous phase are formulated by varying the nature of the hydrocarbon. Polycondensation is then conducted either under conventional heating or microwave irradiation after addition of a commercially available organocatalyst. Solvent elimination and drying lead to the corresponding polyester polyMIPEs.

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Tin dioxide (SnO) nanoparticles were straightforwardly synthesized using an easily scaled-up liquid route that involves the hydrothermal treatment, either under acidic or basic conditions, of a commercial tin dioxide particle suspension including potassium counterions. After further thermal post-treatment, the nanomaterials have been thoroughly characterized by Fourier transform infrared and Raman spectroscopy, powder X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and nitrogen sorption porosimetry. Varying pH conditions and temperature of the thermal treatment provided cassiterite SnO nanoparticles with crystallite sizes ranging from 7.

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