Hierarchical microspheres of Co2CrO4 nanoplates for electrocatalytic water oxidation

Abstract

Co2CrO4 microspheres were hydrothermally synthesized as new electrocatalyst for water oxidation/oxygen evolution reaction (OER). SEM and TEM analyses revealed the hierarchical morphology of the microspheres which are assembly of nanoplates formed by the assembly of individual nanoparticles with ca. 17 nm size. BET analyses showed that this new material has very large surface area (125 m2 g−1). Co2CrO4 microspheres were then used to modify glassy carbon electrode for electrocatalytic investigations in alkaline medium. The results revealed that this new material has promising catalytic performance toward OER with an onset potential of 1.52 V vs. RHE and an overpotential of 456 mV at 10 mA cm−2 current density. In addition, the microspheres presented very good stability during long-term constant potential electrolysis. In general, the catalytic performance of Co2CrO4 microspheres is comparable to the one of benchmark RuO2 with an advantage of being more stable and cost-effective.