Polymetallic Prussian blue analogues with hierarchical structure for high efficiency oxygen evolution reactions.

For the catalyst for water splitting, low overpotential and longer stability is very important. Here, we developed a simple strategy to prepare an efficient catalyst for oxygen evolution by partially phosphating NiFe-LDH and then etching and growing Prussian blue analogues on it. Benefiting from its unique hierarchical structure, the synthesized NiFeCo PBA-NiFeP catalyst showed excellent electrocatalytic performance in 1 M KOH. At 100 mA/cm2, the overpotential of the oxygen evolution reaction (OER) is only 245 mV and exhibits stability for over 50 h. This is superior to most of the OER catalysts reported so far. Its excellent performance is due to its unique hierarchical structure and the synergistic effect between polymetals, which enables it to have abundant active sites and efficient electron transfer. This controllable and universal strategy will provide a new idea for developing interfacial composites and preparing high efficiency electrocatalysts. • A new NiFeCo-PBA-NiFeP composite was prepared by hydrothermal-phosphating-etching process. • The unique hierarchical structure facilitates gas release and contact between the active site and the solution. • The synergistic effect between multiple metals improves the OER properties of the materials. • The combination of NiFeP and NiFeCo PBA improves the OER performance of the material. [ABSTRACT FROM AUTHOR]