Search

Your search keyword '"Dris Ihiawakrim"' showing total 4 results
Start Over Author "Dris Ihiawakrim" Publisher elsevier bv
4 results on '"Dris Ihiawakrim"'

1. A compact photoreactor for automated H2 photoproduction: Revisiting the (Pd, Pt, Au)/TiO2 (P25) Schottky junctions

Author

Pablo Jimenéz-Calvo, Mario J. Muñoz-Batista, Mark Isaacs, Vinavadini Ramnarain, Dris Ihiawakrim, Xiaoyan Li, Miguel Ángel Muñoz-Márquez, Gilberto Teobaldi, Mathieu Kociak, Erwan Paineau, Laboratoire de Physique des Solides (LPS), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Universidad de Granada = University of Granada (UGR), HarwellXPS EPSRC, Department of Chemistry [University College of London], University College of London [London] (UCL), Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), School of Science and Technology [Camerino], Università degli Studi di Camerino = University of Camerino (UNICAM), Scientific Computing Department, STFC, University of Southampton, ANR-18-CE09-0001,C3PO,Confinement et photocatalyse dans des nanotubes polarisés(2018), ANR-10-EQPX-0050,TEMPOS,Microscopie electronique en transmission sur le plateau Palaiseau Orsay Saclay(2010), and European Project: 101068996,LASERION

Subjects
photocatalytic hydrogen, [CHIM.GENI]Chemical Sciences/Chemical engineering, General Chemical Engineering, Photonic profile, co-catalysts, Photoreactor, Environmental Chemistry, [CHIM.CATA]Chemical Sciences/Catalysis, General Chemistry, Schottky junctions, Industrial and Manufacturing Engineering
Abstract

International audience; The configuration and geometry of chemical reactors underpins the accuracy of performance evaluation for photocatalytic materials and, accordingly, the development and validation of thermodynamic and kinetic model reactions. The lack of accurate photonic, mass, and heat transport profiles for photochemical reactors hinder standardization, scale-up, and ultimately comparison between different experiments. This work proposes two contributions at the interface between engineering of chemical process and materials science: (A) an automated compact stainless-steel photoreactor with 40 cm3 and 65 cm2 of volume and area, respectively, for hydrogen photoproduction as a model reaction and (B) the synthesis, characterization, and performance of TiO2 Schottky junctions, using Pd, Pt, or Au nanoparticles (ca. 0.5, 1, 2wt.% loadings each) to validate the operation of the reactor. A photonic profile methodology is implemented to the studied reactor to obtain the local light absorption profile, opening up for evaluation of the local quantum yield calculation for the selected materials. A combination of transmission electron microscopy, (X-ray/ultraviolet) photoelectron/electron, energy loss/infrared spectroscopies, X-ray scattering, inductively coupled plasma atomic emission spectroscopy, and ultraviolet-visible spectrophotometry is employed to determine the distinctive surface and bulk properties to build structure-function correlations. The (Pd, Pt, Au)/TiO2 Schottky junction exhibits H2 production rates slightly higher than previous studies, with quantum yields almost 2-fold higher than reported values. These results, demonstrate that the proposed novel geometry of the photoreactor improves the photonic, heat, and mass profiles. An in-depth analysis of the Au plasmon was investigated coupling electron energy loss spectroscopy, UV-vis, and transmission electron microscope, resulting in insightful information about the Au NP mode at the TiO2 interface.

Published
2023
Full Text
View/download PDF

2. The effect of basic pH on the elaboration of ZnFe2O4 nanoparticles by co-precipitation method: Structural, magnetic and hyperthermia characterization

Author

M. Benaissa, Omar Mounkachi, Walid Baaziz, Dris Ihiawakrim, Ovidiu Ersen, M.A. Ait Kerroum, M. Hamedoun, Abdelilah Benyoussef, Cristian Iacovita, A. Essyed, Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), Institut de chimie et procédés pour l'énergie, l'environnement et la santé (ICPEES), and Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010302 applied physics, Materials science, Spinel, Analytical chemistry, Nanoparticle, 02 engineering and technology, engineering.material, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Magnetostatics, 01 natural sciences, Electronic, Optical and Magnetic Materials, [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, Magnetization, Magnetic hyperthermia, Transmission electron microscopy, 0103 physical sciences, engineering, Magnetic nanoparticles, 0210 nano-technology, Superparamagnetism
Abstract

The present study reports on the synthesis and characterization of zinc iron oxide ZnFe2O4 magnetic nanoparticles (MNPs) using the co-precipitation method. Particular attention has been paid to study the influence of the pH in the range between 9 and 12 on both structural and magnetic properties of the MNPs. X-ray diffraction analysis shows the presence of a single phase of partially invers cubic spinel ferrites ZnFe2O4. Transmission Electron Microscopy (TEM) analysis shows the formation of highly crystalline MNPs and a change of shape from a polyhedral shape at pH 9 to a spherical-like shape for a pH 12. The MNPs mean-size increases from 19 to 33 nm with the increase of pH value. The ZnFe2O4 MNPs are superparamagnetic at room temperature displaying a magnetization of 12 emu/g at the maximum applied static magnetic field. The heating efficiency of spherical zinc ferrites MNPs was evaluated for hyperthermia application and displays a linear increment of the specific absorption rate (SAR) up to 125 (W/gFe) under an alternating magnetic field ranging from 5 to 65 kA/m and operating at a frequency of 355 kHz.

Published
2019
Full Text
View/download PDF

3. Anions and cations distribution in M 5+ /N 3- co-alloyed TiO 2 nanotubular structures for photo-electrochemical water splitting

Author

Valérie Keller, Dris Ihiawakrim, Thomas Favet, Thomas Cottineau, Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Institut de chimie et procédés pour l'énergie, l'environnement et la santé (ICPEES), and Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Nanostructure, Materials science, Anodizing, Mechanical Engineering, Doping, Analytical chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, Thermal treatment, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Electrochemistry, 01 natural sciences, 0104 chemical sciences, chemistry.chemical_compound, chemistry, X-ray photoelectron spectroscopy, 13. Climate action, Mechanics of Materials, Titanium dioxide, Water splitting, General Materials Science, 0210 nano-technology, ComputingMilieux_MISCELLANEOUS
Abstract

Co-alloyed (M,N) titanium dioxide nanotubes were synthesized by a simple anodization process with M-Ti alloys (M = Ta or Nb), followed by a thermal treatment in ammonia to introduce nitrogen in those nanostructure. The photo-electrochemical performances of these co-alloyed samples was compared with the ones of N doped and undoped TiO 2 NTs. Different conditions of thermal treatment under ammonia were studied in order to control the amount of nitrogen introduced in the TiO 2 structure and tend to achieve a balance of charges between Ta 5+ /Nb 5+ cations and N 3- anions. The structure and composition of these materials were characterized by X-Ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS) and Transmission Electron Microscopy (TEM) EDX mapping. This combination of methods confirm the successful introduction of doping atoms, and allowed us to estimate the amount of M 5+ cations and N 3- anions in the TiO 2 NTs. TEM EDX mapping indicates a heterogeneous distribution of Nb 5+ and Ta 5+ cations in the nanotubes that can originate from the use of highly concentrated alloys. External quantum efficiency measurements were used to determine the photo-electrochemical activity of our samples in different spectral domains. A significant improvement of activity in the visible region of the solar spectra was observed for co-alloyed TiO 2 samples when compared to undoped nanotubes but also when compared to N doped TiO 2 . The obtained results indicate that the parameters of the NH 3 thermal treatments should be finely controlled to improve the conversion efficiency in the visible domain for the co-alloyed samples by introducing a precise amount of N 3- in substitution of oxygen in the TiO 2 lattice and to avoid the damaging of the nanotubular structure.

Published
2018
Full Text
View/download PDF

4. Structural, optical, and magnetic properties of polycrystalline Co-doped TiO2 synthesized by solid-state method

Author

Dris Ihiawakrim, A. Derory, Abdelhamid Bouaine, and Guy Schmerber

Subjects
Materials science, Band gap, Mechanical Engineering, Doping, Aucun, Analytical chemistry, Physics::Optics, Magnetic semiconductor, Condensed Matter Physics, Condensed Matter::Materials Science, Tetragonal crystal system, Magnetization, Paramagnetism, Ferromagnetism, Mechanics of Materials, Condensed Matter::Superconductivity, Physics::Atomic and Molecular Clusters, Condensed Matter::Strongly Correlated Electrons, General Materials Science, Crystallite
Abstract

We have used a solid-state method to synthesize polycrystalline Co-doped TiO 2 diluted magnetic semiconductors (DMSs) with Co concentrations of 0, and 0.5 at.%. X-ray diffraction patterns reveal that Co doped TiO 2 crystallizes in the rutile tetragonal structure with no additional peaks. Transmission electron microscopy (TEM) did not indicate the presence of magnetic parasitic phases and confirmed that Co ions are uniformly distributed inside the samples. Optical absorbance measurements showed an energy band gap which decreases after doping with the Co atoms into the TiO 2 matrix. Magnetization measurements revealed a paramagnetic behavior for the as-prepared Co-doped TiO 2 and a ferromagnetic behavior for the same samples after annealed under a mixture of H 2 /N 2 atmosphere.

Published
2012
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results