Bio‐Inspired Aerobic‐Hydrophobic Janus Interface on Partially Carbonized Iron Heterostructure Promotes Bifunctional Nitrogen Fixation.

Competition from hydrogen/oxygen evolution reactions and low solubility of N2 in aqueous systems limited the selectivity and activity on nitrogen fixation reaction. Herein, we design an aerobic‐hydrophobic Janus structure by introducing fluorinated modification on porous carbon nanofibers embedded with partially carbonized iron heterojunctions (Fe3C/Fe@PCNF‐F). The simulations prove that the Janus structure can keep the internal Fe3C/Fe@PCNF‐F away from water infiltration and endow a N2 molecular‐concentrating effect, suppressing the competing reactions and overcoming the mass‐transfer limitations to build a robust "quasi‐solid–gas" state micro‐domain around the catalyst surface. In this proof‐of‐concept system, the Fe3C/Fe@PCNF‐F exhibits excellent electrocatalytic performance for nitrogen fixation (NH3 yield rate up to 29.2 μg h−1 mg−1cat. and Faraday efficiency (FE) up to 27.8 % in nitrogen reduction reaction; NO3− yield rate up to 15.7 μg h−1 mg−1cat. and FE up to 3.4 % in nitrogen oxidation reaction). [ABSTRACT FROM AUTHOR]