Chemical Stability of Mesoporous Oxide Thin Film Electrodes Under Electrochemical Cycling: From Dissolution to Stabilization

SEBASTIÁN ALBERTI; HEINZ AMETISCH; PAULA ANGELOMÉ; GUSTAVO GIMENEZ; PAULA STEINBERG; PAULA STEINBERG; OMAR AZZARONI; GABRIEL YBARRA; GABRIEL YBARRA; SEBASTIÁN ALBERTI; GALO SOLER-ILLIA; GALO SOLER-ILLIA; HEINZ AMETISCH; GUSTAVO GIMENEZ; PAULA ANGELOMÉ; OMAR AZZARONI

LANGMUIR

AMER CHEMICAL SOC

Lugar: Washington; Año: 2019 vol. 35 p. 6279 - 6287

0743-7463

Mesoporous oxide thin films (MOTF) present very high surface areas andhighly controlled monodisperse pores in the nanometer range. These features spurred theirpossible applications in separation membranes and permselective electrodes. However,their performance in real applications is limited by their reactivity. Here, we perform a basicstudy of the stability of MOTF toward dissolution in aqueous media using a variety ofcharacterization techniques. In particular, we focus in their stability behavior under theinfluence of ionic strength, adsorption of electrochemical probes, and applied electrodepotential. Mesoporous silica thin films present a limited chemical stability afterelectrochemical cycling, particularly under high ionic strength, due to their high specific surface area and the interactions between the electrochemical probes and the surface. In contrast, TiO2 or Si0.9Zr0.1O2 matrices present higher stability; thus, they are an adequate alternative to produce accessible, sensitive, and robust permselective electrodes or membranes that perform under a wide variety of conditions.