Constructing Well-dispersed Active Phase via Spontaneous Redox for Electrochemical Nitrate Reduction to Ammonia

In this study, a distinctive multiple core-shell structure of Co nanoparticles inserted into N-doped carbon dodecahedron@Co hydroxide (Co/NCD@Co(OH)2) was synthesized via a spontaneous redox reaction between metallic Co and NO3-, ultimately materializing the fine dispersion and exposure of the active sites. The electronic interaction existing between the Co/NCD core and the Co(OH)2 shell brings a synergistic effect, conspicuously lessens the overpotential, and reinforces the yield-rate and Faradaic efficiency of NH3 for electrochemical nitrate-ammonia conversion. This study underlines the spontaneous redox between catalysts and substrate, rendering it as a synthetic strategy for designing genuine and well-dispersed active sites.