Homogeneous nanosheet Co₃O₄ film prepared by novel unipolar pulse electro-deposition method for electrochemical water splitting

A unipolar pulse electro-deposition (UPED) method is used to prepare nanosheet Co₃O₄ film on a carbon rod substrate in aqueous solution and compared with other conventional methods, i.e., the cyclic voltammetry (CV) method, potentiostatic method (PM) and pulse potentiostatic method (PPM). Co₃O₄ films prepared by the UPED method show a more uniform structure on carbon rod and higher catalytic activity than those by other methods, and oxygen evolution reaction over it with an overpotential of 275 ± 2.3 mV results in a current density of 10 mA cm^-2 in 1.0 mol L^-1 KOH. Such an excellent performance should be attributed to its highly porous nanosheet structure with honeycomb-like morphology.