Abstract

Highly stable suspensions of monodispersed ruthenia nanoparticles have been prepared via a sustainable aqueous oxidative pathway. The nanoparticles (2 nm) have been thoroughly characterized by TEM, XRD, XPS, MS-TGA and thermodiffraction. The addition of hydrogen peroxide in the RuCl 3 solution provokes a fast oxidation of Ru(iii) ions into Ru(iv). This increases the rate of the hydrolysis/condensation reactions and further promotes the nucleation over the growth of the particles. The very high stability conditions of the colloidal suspension have been studied. This aqueous one-step process, which uses no organic solvent or toxic pollutant additive, is quick and produces calibrated ruthenia nanoparticles in high yields. It presents a green alternative to the preparation and use of ruthenia. As examples, two applications are presented. In the first, RuO 2 coatings have been tested for their electrical capacitance. In the second, RuO 2/TiO 2 catalysts, prepared from the controlled deposition of ruthenia nanoparticles on TiO 2 particles, have been proven to be highly effective for the production of methane from CO 2. This journal is © The Royal Society of Chemistry.