A Molecular Approach to RuO2-Based Thin Films: Sol-Gel Synthesis and Characterization

RuO2-based materials are attractive candidates for a variety of technological applications, especially in catalysis andelectrocatalysis. In this field, much research is nowadays focused on the development of nanosystems, especially as thinlayers, with tailored compositional and microstructural properties. In the present study, RuO2-based coatings wereprepared by a sol-gel route. RuO2 nanocrystalline films were obtained by dip-coating from alcoholic solutions ofRu(OEt)3 and subsequent thermal treatments in air or N2 between 100 and 400 C. Mixed RuO2-SiO2 coatings weresynthesised starting from solutions of RuCl3 and [NH2(CH2)2NH(CH2)3Si(OMe)3]. The silicon compound was usedeither as precursor for the silica matrix or as complexing agent for the Ru ions, to synthesise ruthenium oxide-basednanoaggregates directly in the SiO2 glass. The microstructure of the systems was studied by X-ray diffraction, whiletheir surface and in-depth chemical composition was analysed by X-ray photoelectron spectroscopy. Furthermore, thethermal evolution of RuO2-SiO2 coatings was investigated by optical absorption.