Ion transport and capacitive properties of RuO2-SnO2 binary films

This paper reports the RuO2-SnO2 binary film synthesis and the influence of the SnO2 composition increase in the ion transport and pseudocapacitive properties of RuO2. The binary oxide was synthesized by polymeric precursors method followed deposition on a titanium substrate. XRD analysis showed the phases formed and the crystallites size of the samples. SEM allowed studying the morphology variation of the films with the addition of SnO2. The material obtained was evaluated by electrochemical techniques in 1 M H2SO4 electrolyte solution. The voltammograms showed that the pseudocapacitive characteristic of the RuO2 - SnO2 binary film remained even for greater amount of SnO2 in the binary mixture. The electrochemical impedance spectroscopy results are discussed in terms of complex capacitance and complex power. The relaxation time constant of the systems and capacitance values at low frequency, were determinate from complex capacitance plots.