Interconnected Copper Cobaltite Nanochains as Efficient Electrocatalysts for Water Oxidation in Alkaline Medium.

The present work is focused on the protective-agent-free synthesis of interconnected copper cobaltite (Cu0.3 Co2.7 O4 ) nanochains by temperature-controlled solvothermal method followed by post-thermal treatment of the precursors. Furthermore, Cu0.3 Co2.7 O4 interconnected nanochains are employed as electrocatalyst for water oxidation in alkaline medium for the first time. Extensive studies of physiochemical properties showed the formation of interconnected 1D nanochains of Cu0.3 Co2.7 O4 exhibiting a larger specific surface area (139.5 m2 g-1 ) and enhanced electrochemical water oxidation ability. It delivered excellent mass activity (∼50.0 A g-1 ), high anodic current density (∼124.9 mA cm-2 at 1.75 V versus reversible hydrogen electrode), and turnover frequency (∼4.26 × 10-2 s-1 ) in 1.0 M KOH. These Cu0.3 Co2.7 O4 nanochains also demonstrated low overpotential (∼351 mV) and good cycling stability (1000 cycles) in strong alkaline media. The fabricated Cu0.3 Co2.7 O4 nanochains could be a good alternative to the commercial OER electrocatalysts (RuO2 and IrO2 ) and also advantageous to the development of efficient, cost-effective, and durable electrocatalysts for electrochemical water splitting.