Hierarchical TiO2@Ru0.9Ir0.1O2 as Highly-durable Electrocatalyst for Oxygen Evolution Reaction

Hierarchical acid-durable TiO2@Ru0.9Ir0.1O2 electrodes were designed and fabricated through the combination of in-situ hydrothermal method and thermal pyrolysis. The evolution of intermediate layers for electrodes were realized from nanosheets and nanosheet-nanowire hybrids to nanowires through regulating the hydrothermal time. Then morphology effects of TiO2 nanostructures were investigated. Results show that the crystal planes of (101) and (110) of rutile-phase RuO2 are exposed. The oxygen evolution potential of TiO2-nanowire@Ru0.9Ir0.1O2 is about 51 mV lower than that of Ti-matrix electrode with a current density of 30 A g(-1). Chronoamperometric results tested at 1.541 V vs RHE that the response current of TiO2-nanowire@Ru0.9Ir0.1O2 is 10.9 times as much as that of Ti-matrix electrode (4.46 vs 0.41 A g(-1)), while the electrochemically active surface area of TiO2-nanowire matrix electrode is much higher than that of Ti-matrix one (9.115 vs 1.896 mF). Cyclic durability results of electrodes tested in the acid solution show that the. Thus the introduction of TiO2 nanostructures benefits to enhance the long-term durability of electrode materials.