Structure, electrochemical properties and functionalization of amorphous CN films deposited by femtosecond pulsed laser ablation

Amorphous carbon nitride (a-C:N) material has attracted much attention in research and development. Recently, it has become a more promising electrode material than conventional carbon based electrodes in electrochemical and biosensor applications. Nitrogen containing amorphous carbon (a-C:N) thin films have been synthesized by femtosecond pulsed laser deposition (fs-PLD) coupled with plasma assistance through Direct Current (DC) bias power supply. During the deposition process, various nitrogen pressures (0 to 10 Pa) and DC bias (0 to ¿ 350 V) were used in order to explore a wide range of nitrogen content into the films. The structure and chemical composition of the films have been studied by using Raman spectroscopy, electron energy-loss spectroscopy (EELS) and high-resolution transmission electron microscopy (HRTEM). Increasing the nitrogen pressure or adding a DC bias induced an increase of the N content, up to 21 at.%. Nitrogen content increase induces a higher sp2 character of the film. However DC bias has been found to increase the film structural disorder, which was detrimental to the electrochemical properties. Indeed the electrochemical measurements, investigated by cyclic voltammetry (CV), demonstrated that a-C:N film with moderate nitrogen content (10 at.%) exhibited the best behavior, in terms of reversibility and electron transfer kinetics. Electrochemical grafting from diazonium salts was successfully achieved on this film, with a surface coverage of covalently bonded molecules close to the dense packed monolayer of ferrocene molecules. Such a film may be a promising electrode material in electrochemical detection of electroactive pollutants on bare film, and of biopathogen molecules after surface grafting of the specific affinity receptor.This work is produced with the financial support of the Future Program Lyon Saint-Etienne (PALSE) from the University of Lyon (ANR-11-IDEX-0007), under the “Investissements d'Avenir” program managed by the National Agency Research (ANR)

Low-cost 3D-nanoflowers electrode for energy charge storage to pseudocapacitor device

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High Magnetic Moment of FeCo Nanoparticles Produced in Polyol Medium

International audienceHigh magnetization Fe55Co45 alloy nanoparticles have been successfully synthesized by the polyol reduction process followed by annealing under argon. The diethylene glycol (DEG) was used as solvent and reducing agent simultaneously in this process. All the synthesized samples of FeCo nanoparticles were annealed at 873K for different times. The alloy formation processes, the evolution of the microstructure, and the magnetic properties have been investigated before and after samples annealing. The X-ray diffraction of the synthesized product before annealing shows that a cobalt ferrite is spinel structure of crystallite size of about 10 nm. X-ray diffraction analysis of the samples annealed at 873K for different times also shows that of the FeCo alloy has been obtained by reducing the cobalt ferrite. It has been confirmed the formation of a body-centered-cubic (bcc) single phase structure where the wt.% increases with annealing times leading to a pure phase after annealing during 4h. These results are confirmed by transmission electron microscopy study. The saturation magnetization of the Fe-Co alloys increases with annealing time, indicating an increasing homogeneity in composition and the single bcc FeCo phase formation. The highest saturation magnetization of 235 Am2.kg−1 with a low coercivity of 7.5 mT was obtained for the Fe55Co45 nanoparticles annealed during 4h. The anisotropy constant K has been extracted and we have shown that increases with the annealing time

Experimental design approach for the synthesis of 3D-CoFe2O4 nanoflowers thin films by low-cost process

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High Magnetic Moment CoFe Nanoparticles

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Synthesis of (2D) MNPs nanosheets of nickel ferrite using a low-cost co-precipitation process

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High Magnetic Moment CoFe Nanoparticles

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Un incidentalome surrenalien inhabituel: le ganglioneurome

Le ganglioneurome est une tumeur neurogène bénigne, rare, qui se développe à partir des cellules ganglionnaires sympathiques. Elle se localise essentiellement dans la région rétropéritonéale. La localisation surrénalienne est rare. Nous rapportons un cas de ganglioneurome surrénalien chez une femme âgée de 42 ans, asthmatique et atteinte de dilatation des bronches. La tumeur est découverte fortuitement sur un scanner thoraco-abdominal demandé dans le cadre du bilan étiologique de sa dilatation des bronches. Le diagnostic a été confirmé par l’examen anatomopathologique