Electrochemical Properties of Silver Nanoparticles in Mesoporous Silica and Titania Films: Specific Behavior of Titania Composite

Abstract

Electrochemical behavior of silver nanoparticles in mesoporous oxides electrodes is investigated. Mesoporous SiO 2 and TiO 2 films deposited on FTO (fluorine-doped tin oxide) and containing Ag nanoparticles (NPs) are used as electrodes. The study of voltammetric curves (CVs) and the diffusion of Ag + ions out of the films highlight the importance of the retention of Ag + ions by the TiO 2 films. By varying several factors such as the speed rate or the initial potential, we observe the existence of the two potentials' anodic peaks. These are explained by the nature of two silver NP populations created in two distinct areas in the film and with different size distributions, as shown by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations. The size distributions of the two NP populations allow the position and shape of each of the oxidation peaks in the CVs to be adequately simulated.