Non-precious cobalt oxalate microstructures as highly efficient electrocatalysts for oxygen evolution reaction

Well-defined cobalt oxalate (CoC2O4 center dot 2H(2)O) microstructures with controllable morphologies have been successfully synthesized by a simple solvothermal process. The resulting CoC2O4 center dot 2H(2)O microrods (MRs) and micropolyhedrons (MPs) can be easily controlled by rationally tuning the composition of solvents. It is experimentally demonstrated that CoC2O4 center dot 2H(2)O microstructures as nonprecious metal based electrocatalysts exhibit remarkable activity for catalyzing OER in alkaline medium. Such performance is found to be closely dependent on the morphology of CoC2O4 center dot 2H(2)O microstructures. The MRs with higher aspect ratio and more active Co sites manifest a small OER onset potential, large anodic current and long-term durability, which are superior to the MPs, derived Co3O4 MRs, and previously reported cobalt oxalate electrocatalysts, and even compare favorably with most previously reported Co-based OER electrocatalysts.