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.