Mixed RuO2/TiO2 uniform microspheres synthesized by low-temperature ultrasonic spray pyrolysis and their advanced electrochemical performances

Uniformly-shaped, spherical RuO₂/TiO₂ particles were synthesized exclusively by one-step ultrasonic spray pyrolysis (USP) of a mixture of n-butylorthotitanate and ruthenium chloride acidic aqueous solutions. The USP temperature was 200 °C – quite below the typical conversion temperatures of the precursors to the oxides. Basic electrochemical properties of RuO₂/TiO₂ USP powders (as-prepared or additionally dried and/or thermally treated) in the form of a thin layer applied onto glassy carbon electrode are investigated and compared to the properties of powder synthesized at quite higher temperature of 800 °C. The coatings of activated titanium anode (ATA) were prepared from RuO₂/TiO₂ USP powders in order to check the anode electrolysis stability and to correlate the anode properties to those of native USP powders. Low-temperature material showed much better performances than high-temperature one. ATA obtained from low-temperature USP powder showed considerably higher stability. The obtained results are found to be in close correlation to the powder and coating structure, composition and morphology affected by subsequent thermal treatment of the material synthesized at low USP temperature.