A highly efficient water electrolyser cell assembled by asymmetric array electrodes based on Co, Fe-doped Ni(OH)2 nanosheets

Hydrogen is an ideal clean sustainable energy source if it is produced via water electrolyser using power generated by renewable energy systems (RES) such as solar panels and wind turbines. In this study, cobalt (Co) and iron (Fe) doped nickel (Ni) hydroxide nanosheets directly formed onto the surface of Ni foam are synthesized and developed for use as hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) catalysts. When Co-doped nickel hydroxide is used as HER catalyst, it exhibited a high HER activity with a durability better than Pt/C. The as-prepared Fe-doped nickel hydroxide show an OER activity, which is even higher than that of RuO2. When Fe-doped nickel hydroxide and Co-doped nickel hydroxide are both used as HER and OER catalysts in a water electrolyser cell, a current density of 10 mA cm(-2) at a cell voltage of 1.59 V is observed, a similar value than that obtained for a water electrolyser based on state-of-the-art RuO2 and Pt/C catalysts. Moreover, the as-prepared Fe, Co doped nickel hydroxide also exhibit a good durability when compared to RuO2 and Pt/C under water electrolyser conditions.