Development of nickel-cobalt bimetallic/conducting polymer composite used as a catalyst in the oxygen evolution reaction (OER)

This paper discusses results on the development of nickel-Cobalt Bimetallic/conducting polymer composite layer used as a catalyst in the Oxygen evolution reaction (OER). Based on cost, corrosion stability and over-potential, nickel is an advantageous material for the anode in alkaline water electrolysis. However, the use of this metal is associated with two main difficulties: the progressive deactivation of the anode occurs at higher potentials, presumably due to the modification of the active nickel species into inactive ones, and the potential becomes unavoidably increasingly positive over time, thus decreasing the efficiency of the electrode. Nickel-based bimetallic catalysts, such as Ni-Ir, Ni-Co, Ni-Mn, Ni-Fe, usually obtained by electrodeposition, have been widely studied in recent years in the search for catalysts that improve the activity of nickel towards the OER. However, polymeric films were used by several researchers to incorporate various metal complexes, with an aim of improving the activity and stability of electrodes surfaces. Modified electrodes obtained by these polymeric films are characterized by good ionic conductivity and permeability. These as well, we conducted a study of the oxygen evolution reaction in the basic medium on electrodes modified by polymerization of aniline and electrodeposition of (Nickel-Cobalt) bimetallic. In the present work, the electrodeposition technique has been adopted to introduce different amounts of cobalt into the nickel. Surface morphologies of the electrodeposits and their electrocatalytic properties have been studied for the oxygen evolution reaction in NaOH solutions. The Ni-Co bimetallic film is much more reactive than Ni for the OER. Co has a significant effect on the OER. The effect of Co deposited with NiO film depends on its content. (paper)