Extensive water oxidation to reduction of ultra-durable non-precious electrocatalysts for alkaline water electrolysis

摘要

The in-situ hybridization of an electrochemical catalyst-current collector has a low reaction barrier in water electrolysis while being active and functions as a highly stable electrode. A self-formed Ni_3Se_2/NF electrode made of inexpensive and non-precious metal found in large amounts has the oxygen-generating anode current density of 100 mA/cm^2 at an overvoltage of 315 mV, being relative to reversible hydrogen electrode, at 1 M KOH. At a constant current density of 100 mA/cm^2, the Ni_3Se_2/NF electrode shows a slight potential loss of 5.5% in a strong alkaline electrolyte while having high oxygen evolution reaction (OER) stability for 285 hours. Accordingly, alkaline water electrolysis cells constructed with Ni_3Se_2/NF and NiCo_2S_4/NF need 1.58 V to generate a current with the current density of 10 mA/cm^2 when being driven continuously for 500 hours at 1 M KOH. In the alkaline water electrolysis cells, the mineral oil water degradation using solar cell panels can be a promising approach to promote independence from electricity in terms of improving the hydrogen fuel cost efficiency. Overall, the method can simplify an apparatus and various processes to be used as an energy-efficient method for lowering the cost of a water decomposition apparatus.