Preparation of the electrode using NiFe2O4 powder for the alkaline water electrolysis

The coin electrode was prepared by mixing the binder (polyethylene glycol or styrene butadiene rubber) and NiFe2O4 powder which was synthesized by a co-precipitate method, to use in the alkaline water electrolysis. The over-potential of the prepared coin electrode was measured in 7 mol L−1 KOH solution for an oxygen evolution reaction (OER) and a hydrogen evolution reaction (HER). From the data, it was estimated that the prepared coin electrode is useful for the electrode in the alkaline water electrolysis with its low over-potential (1.57 V and 2.20 V for OER and HER, respectively, at the current density of 0.41 A cm−2).