Microstructure, morphology and electrochemical property of RuO270SnO230 mol% and RuO230SnO270 mol% coatings

The DSA anodes based on RuO₂–SnO₂ oxides are most employed in chlorine-alkali cells. Their properties are strongly influenced by the mixed-oxide coating structures. In this paper, two RuO₂–SnO₂/Ti DSA anodes with different Ru and Sn molar ratios were prepared through a sol–gel technique. The nano-structure, morphology, grain structure and composition of the coatings were investigated by means of XRD, SEM and TEM. XRD analysis indicates two rutile-type solid solutions are formed. Peak profile analysis shows that in the solid solution where SnO₂ is the major component smaller crystallites (about 20–30 nm) are formed than in those where RuO₂ is the major component (about 100–200 nm). The SEM images reveal the coating with high level of SnO₂ possesses more accumulated and compact structures. The EDS analysis indicates that two DSA anodes coatings in which SnO₂ is similar to the designed concentration are prepared by the sol–gel method. TEM characterization shows the polygonal crystallites are present in the obtained RuO₂–SnO₂ coatings. The voltages of Cl₂-evolution and O₂-evolution suggest both RuO₂–SnO₂/Ti DSA anodes have a good electrochemical performance and can be used for the chlorite industrial productions.