Electroactive Area from Porous Oxide Films Loaded with Silver Nanoparticles: Electrochemical and Electron Tomography Observations

Autor: Laurence Bois, Fernand Chassagneux, Nelly Couzon, Lucian Roiban, Arnaud Brioude, Mathieu Maillard
Přispěvatelé: Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Matériaux, ingénierie et science [Villeurbanne] (MATEIS), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)
Rok vydání: 2019
Předmět:
Zdroj: ACS Applied Materials & Interfaces
ACS Applied Materials & Interfaces, Washington, D.C. : American Chemical Society, 2019, 11 (40), pp.37270-37278. ⟨10.1021/acsami.9b11581⟩
ISSN: 1944-8252
1944-8244
DOI: 10.1021/acsami.9b11581⟩
Popis: Electrochemical studies of nanomaterial-based electrodes have been widely developed for catalyst and energy-harvesting applications. The evolution of these electrodes over time and their efficiency have been extensively studied and analyzed in order to optimize their performance. However, the electrochemical responses of electrodes are rarely studied in terms of the position of the active species within these electrodes. In this paper, we highlight that the spatial location of silver nanoparticles (NPs) embedded inside semiconductive porous films, TiO2 or Fe2O3, is crucial for the electrochemical response. In fact, by using cycling voltammetry and electron tomography experiments, we show the existence of an "electroactive area", corresponding to a reduced thickness of the sample in close vicinity to a fluorine-doped tin oxide substrate where most of the electrochemical responses originate. Our results demonstrate that, for a film thickness of several hundred nanometers, only less than 30 nm close to the substrate responds electrochemically. However, cyclic voltammetry empties the electroactive area of silver NPs. Therefore, application of chronoamperometry coupled to irradiation allowed regeneration of this area thanks to an increased diffusion of silver species. In this paper, we also show the significant diffusion of silver species within the film during electrochemical experiments, a phenomenon even increased by irradiation. These results are therefore an important step that shows the importance of the localization of active species within a porous film and help in understanding and increasing the durability of nanomaterial-based electrodes.
Databáze: OpenAIRE
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