In the depth understanding of reversible ionic transfers of layered double hydroxides by in operando electrochemical and gravimetric measurements coupled with grazing incidence wide angle X-ray scattering - Laboratoire Interfaces et Systèmes Electrochimiques Accéder directement au contenu
Communication Dans Un Congrès Année : 2019

In the depth understanding of reversible ionic transfers of layered double hydroxides by in operando electrochemical and gravimetric measurements coupled with grazing incidence wide angle X-ray scattering

Résumé

A layered double hydroxide (LDH) material consists of a stacking of positively charged brucitic layers due to the substitution of some divalent cations M(II) with trivalent cations M(III). The charge compensation is managed by the ionic species intercalated into the interlayer spacing i.e. water and anions A n-­‐ . This leads to the general formula: [M(II) 1-­‐ x M(III) x (OH) 2 ]x+ (An-­‐x/n ).mH2 O. As a consequence, LDHs provide a high capacity for anion exchange. For wide applications in terms of energy storage device or water treatment, the reversibility of the ion transfer between the electrolyte and the interlayer spacing of the LDH needs to be further investigated. Tuning the oxidation state of the electroactive metallic sites with electrochemistry reversibly modifies the positive charge excess within the layers. The low electronical conductivity performance of the LDH is promoted by preparing thin films coated on a working electrode surface. The related ion transfer is probed by coupling electrochemistry with a quartz crystal microbalance sensitive to the ng (EQCM). Here, we investigate for the first time the nature, kinetics, exchanged concentration and mass of each ion species transferred from the electrolyte to the material related to the oxidation and reduction of the electroactive components of the LDHs. This is made possible with the ac-­‐electrogravimetry technique, developed at LISE, that couples electrochemical impedance and mass/potential transfer functions measurements. The in situ grazing-­‐incident-­‐wide-­‐angle-­‐X-­‐ray-­‐scattering (GIWAXS, 20 keV) coupled with EQCM at synchrotron enables to measure the change in the interlayer spacing of the LDH as well as the mass variation of the material in solution during cyclic oxidation/reduction of the metal sites. It confirms and demonstrates further the mechanisms of the ionic transfers between the electrolyte and the interlayer distance.

Domaines

Chimie
Fichier non déposé

Dates et versions

hal-04013423 , version 1 (03-03-2023)

Identifiants

  • HAL Id : hal-04013423 , version 1

Citer

Elise Duquesne, Stéphanie Betelu, Denis Limagne, Michel Goldmann, Cyrille Bazin, et al.. In the depth understanding of reversible ionic transfers of layered double hydroxides by in operando electrochemical and gravimetric measurements coupled with grazing incidence wide angle X-ray scattering. International Conference on Clay Science and Technology (EUROCLAY), GFA, Jul 2019, Paris, France. ⟨hal-04013423⟩
18 Consultations
0 Téléchargements

Partager

Gmail Facebook X LinkedIn More