ZnO templated selenized and phosphorized cobalt-nickel oxide microcubes as quick-witted alkaline water oxidation electrocatalyst.

Abstract

Oxygen electrocatalysis is of remarkable significance for electrochemical energy storage and conversion technologies, together with fuel cells, metal-air batteries and water splitting devices. Substituting noble metal-based electrocatalysts by decidedly effective and low-cost\xa0 metal-based oxygen electrocatalysts is imperative for the commercial application of these technologies. Herein, we present a novel strategy to fabricate selenized and phosphorized porous cobalt-nickel oxide microcubes through sacrificial ZnO sphere template and employed it as OER electrocatalyst. The selenized samples manifest desirable and robust OER performance, with comparable overpotential at 10 mA cm -2 (312 mV) as RuO2 (308 mV) and better activity when the current reaches 13.7 mA cm -2 . The phosphorized samples exhibit core-shell structure with low-crystalline oxides inside amorphous phosphides, which ensures superior activity towards RuO2 with the same overpotential (at 10 mA cm -2 ) yet lower Tafel slope. Such surface doping method possibly will give many\xa0inspirations for engineering electrocatalysts applied in water oxidation.