Polarized Electronic Configuration in Transition Metal–Fluoride Oxide Hollow Nanoprism for Highly Efficient and Robust Water Splitting

Metal–fluoride possesses a high potential as new high-performance water oxidation catalysts due to a highly polarized electronic configuration. However, low conductivity, related to high iconicity in metal–fluorine bonds, and instability of metal–fluoride in alkaline solution act as major roadblocks for using metal–fluoride as a highly efficient electrocatalyst. Here, we first disclose a novel strategy to design the electrochemically active and stable metal–fluoride electrocatalysts, nickel–cobalt fluoride oxide (NCFO), for water oxidation. The incorporation of F leads to substantial increase of the number of surface active sites with unsaturated electronic structure, which is beneficial for boosting electrocatalytic activity.