Design of Trimetallic NiMoFe Hollow Microspheres with Polyoxometalate‐Based Metal‐Organic Frameworks for Enhanced Oxygen Evolution Reaction

Abstract Design of efficient and inexpensive oxygen evolution reaction (OER) catalysts is the key to realizing the wide application of water electrolysis in industrial production. Herein, we synthesized trimetallic hollow microspheres composed with FeNi nanoparticles and nitrogen‐doped carbon‐based Ni 2 Mo 3 N (NiMoFe@NC700) using a “PBA@POMOF” strategy. In order to synthesize the precursor with ideal morphology and structure in the least steps, a polyoxometalate based metal‐organic framework (POMOF) is used as a substrate to grow a Ni−Fe‐based Prussian blue analogue (NiFePBA) on it. Benefiting from the hollow sphere structure formed by stacking flakes, better charge transfer performance and the synergistic effect between Ni 2 Mo 3 N and Fe 0.64 Ni 0.36 , the final product, NiMoFe@NC700, exhibits low overpotentials of 288 and 360 mV to achieve current densities of 10 and 50 mA cm −2 for OER in 1 M KOH, respectively, which is superior to the benchmark IrO 2 catalyst. This work proposes a facile and effective strategy to synthetize carbon‐based polymetallic OER electrocatalysts based on PBA@POMOF.