Bio-inspired NiCoP/CoMoP/Co(Mo3Se4)4 @C/NF multi-heterojunction nanoflowers：Effective catalytic nitrogen reduction by driving electron transfer

Electrochemical nitrogen reduction reaction can be adopted to generate renewable ammonia. That is recognized as a sustainable alternative to the Haber-Bosch process. However, the limited electrocatalytic activity remains the primary obstacle against viable application of the electrocatalytic ammonia fixation. Herein, a biomimetic three-dimensional NiCoP/CoMoP/Co(Mo 3 Se 4 ) 4 @C/NF electrocatalyst is designed to have excellent NRR performance with an NH 3 yield rate of 24.54 μg h −1 cm −2 and Faradaic efficiency of 23.15%. Based on the experimental and theoretical results, NiCoP/CoMoP/Co(Mo 3 Se 4 ) 4 @C/NF electrocatalyst perfectly simulates the structural characteristics of biological nitrogenase, where Co(Mo 3 Se 4 ) 4 acts as the major active center while NiCoP and CoMoP contribute to controlling the electron transfer during NRR. Additionally, the coexistence of the three different heterojunction interfaces induces more effective electronic structure modulation compared with the single interface, thereby optimizing the reaction energy barrier of intermediates. This work has developed a synergistic strategy to boost the reaction kinetics via introducing multiple heterojunction interfaces. • NiCoP/CoMoP/Co(Mo 3 Se 4 ) 4 @C/NF have excellent N 2 reduction performance. • NiCoP/CoMoP/Co(Mo 3 Se 4 ) 4 @C/NF simulates the structure of nitrogenase. • Multiple heterojunction interfaces induce effective electron redistribution. • Multiple heterojunction interfaces optimize the reaction energy barrier.