Fe-doped CoNi0.5P Hierarchical Arrays as Efficient Bifunctional Electrocatalysts for Overall Water Splitting: Evolution of Morphology and Coordination of Catalytic Performance

Design and synthesis of bifunctional electrocatalysts with high efficient and durability for electrolytic water splitting still remain an important matter for the research of renewable energy systems. Herein, a series of CoNi0.5FexP/CC (x=0, 0.08, 0.125, 0.25, 0.5) catalysts have been successfully prepared by a simple hydrothermal and phosphorization process, and directly used as bifunctional electrocatalysts for OER and HER. Benefiting from the suitable Fe element doping content and novel nanowire-nanosheet co-existent hierarchical nanostructure, the optimal CoNi0.5Fe0.125P/CC catalyst shows an outstanding bifunctional catalytic performance, with 344 mV low overpotential to reach at 100 mA cm(-2) during OER process and 74 mV overpotential to reach at 10 mA cm(-2) during HER process. The water electrolysis device employing CoNi0.5Fe0.125P/CC as cathode and anode at the same time, it only requires as low as 1.61 V of voltage to achieve the current density of 10 mA cm(-2) in alkaline solution, implying a great practical application value of this novel hierarchical nanostructured material for overall water splitting.