CoO/TiN nanowires array as an effective self-supported catalyst for oxygen evolution reaction

Abstract A nanowires array with CoO/TiN heterostructure has been constructed and applied as the binder- and conductive-agent-free anode for oxygen evolution reaction. A well-aligned CoO/TiN nanowires composite array was obtained by electrodeposition and subsequently thermal treatment. Such an anode reveals overpotential of 270 mV at current density of 10 mA cm−2 in 1.0 M KOH solution, which is much lower than comparison catalysts. Moreover, CoO/TiN catalyst exhibits good stability which can maintain the vast majority of OER activities (more than 90% of initial current densities) for a 15 h long-termed chronoamperometry test. The enhanced performance should be attributed to the synergistic effect of heterostructure and advantages of the well-aligned CoO/TiN nanowires morphology which could largely increase the amount of contact areas between electrolyte and active sites.