Stable Ti/RuO2–Sb2O5–SnO2 electrodes for O2 evolution

RuO2-based electrodes are generally known to be unstable for O2 evolution. In this paper, a stable type of RuO2-based electrode, Ti/RuO2–Sb2O5–SnO2, is demonstrated for O2 evolution. In the ternary oxide coating, RuO2 serves as the catalyst, SnO2 as the dispersing agent, and Sb2O5 as the dopant. The accelerated life test showed that the Ti/RuO2–Sb2O5–SnO2 electrode containing 12.2 molar percent of RuO2 nominally in the coating had a service life of 307 h in 3 M H2SO4 solution under a current density of 0.5 A cm−2 at 25 °C, which is more than 15 times longer than other types of RuO2-based electrodes. Instrumental analysis indicated that RuO2–Sb2O5–SnO2 was a solid solution with a compact structure, which contributed to the stable nature of the electrode.