LaCoO 3 -modified RuO 2 –TiO 2 /Ti electrode as an efficient electrocatalyst for oxygen evolution reaction

A RuO 2 –TiO 2 /Ti electrode modified with LaCoO 3 was successfully fabricated by thermal decomposition and its electrochemical properties were evaluated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and stability tests. In contrast with an unmodified RuO 2 –TiO 2 /Ti electrode, the LaCoO 3 –RuO 2 –TiO 2 /Ti electrode displays a more uniform layer with smaller microparticles. This electrode also displays higher OER performance with lower overpotential (289 mV vs. 348 mV) at a current density of 10 mA cm −2 and lower Tafel slope (87 mV dec −1 vs. 104 mV dec −1 ) than the unmodified RuO 2 –TiO 2 /Ti electrode. The modified LaCoO 3 –RuO 2 –TiO 2 /Ti electrode possesses larger current density, higher specific voltammetric charge, and lower charge transfer resistance ( R ct ) than the unmodified RuO 2 –TiO 2 /Ti electrode does in a KOH solution, according to CV and EIS studies. The LaCoO 3 –RuO 2 –TiO 2 /Ti electrode is very stable. The results show that the modified LaCoO 3 –RuO 2 –TiO 2 /Ti electrode presents higher electrocatalytic activity and good stability for OER. Graphic abstract