title: Synthesis and properties of ZnO-HMD@ZnO-Fe/Cu core-shell as advanced material for hydrogen storage.
abstract: In this paper, a new synthetic strategy towards functionalized ZnO-HMD@ZnO-Fe/Cu core-shell using sol-gel process modified by chemical grafting of hexamethylenediamine (HMD) on the core and in-situ dispersion of Cu0/Fe0as metallic nanoparticles (M-NPs) on the shell. The as-prepared core-shell materials were fully characterized by transmission electron microscopy, X-ray powder diffractometry, diffuse reflectance and FT-IR spectrophotometery, photoluminescence, and complexes impedance spectroscopy measurements. The XRD patterns agreed with that of the ZnO typical wurtzite structure, indicating good crystallinity of ZnO-HMD@ZnO-Fe/Cu, with the presence of Fe0and Cu0phases. Hexamethylenediamine grafting and M-NPs insertion were highly activated and enhanced the core and shell interface by the physiochemical interaction. After functionalization, luminescence intensities and electrical properties of both core and core-shell nanoparticles are improved, indicating the effects of the surface groups on the charge transfer of ZnO-HMD@ZnO-Fe/Cu. The hydrogen capacity retention was depended strongly on the composition and structure of the obtained core-shell. Iron/Copper-loaded ZnO-HMD@ZnO materials exhibited the highest capacity for hydrogen storage. The excellent stability and performance of the ZnO-HMD@ZnO-Fe/Cu core-shell make it an efficient candidate for hydrogen storage.
authors.affiliation: Research Unit: Environment, Catalyzes and Process Analysis, ENIG, University of Gabes, Tunisia; Normandie Université, COBRA, UMR6014 et FR3038, Université de Rouen, INSA de Rouen, CNRS, 55, rue Saint Germain, 27000 Evreux, France; Nanoqam, Department of Chemistry, University of Quebec at Montreal, QC H3C 3P8, Canada. Electronic address: bouazizi.nabil@hotmail.fr.
authors.forename: N
authors.initials: N
authors.lastname: Bouazizi
authors.affiliation: Useful Materials Valaorization Laboratory, Borj Cedria, Tunis, Tunisia.
authors.forename: T
authors.initials: T
authors.lastname: Boudharaa
authors.affiliation: Normandie Université, COBRA, UMR6014 et FR3038, Université de Rouen, INSA de Rouen, CNRS, 55, rue Saint Germain, 27000 Evreux, France.
authors.forename: R
authors.initials: R
authors.lastname: Bargougui
authors.affiliation: Normandie Université, COBRA, UMR6014 et FR3038, Université de Rouen, INSA de Rouen, CNRS, 55, rue Saint Germain, 27000 Evreux, France. Electronic address: julien.vieillard@univ-rouen.fr.
authors.forename: J
authors.initials: J
authors.lastname: Vieillard
authors.affiliation: Department of Chemistry, Faculty of Sciences, University of Gabes, Tunisia.
authors.forename: S
authors.initials: S
authors.lastname: Ammar
authors.affiliation: Normandie Université, COBRA, UMR6014 et FR3038, Université de Rouen, INSA de Rouen, CNRS, 55, rue Saint Germain, 27000 Evreux, France.
authors.forename: F
authors.initials: F
authors.lastname: Le Derf
authors.affiliation: Nanoqam, Department of Chemistry, University of Quebec at Montreal, QC H3C 3P8, Canada. Electronic address: azzouz.a@uqam.ca.
authors.forename: A
authors.initials: A
authors.lastname: Azzouz
keywords: Copper nanoparticles; Hexamethylenediamine; Hydrogen storage; Iron nanoparticles; Surface modification