Electrocatalytic production of ammonia: Biomimetic electrode–electrolyte design for efficient electrocatalytic nitrogen fixation under ambient conditions

Abstract

Electrocatalytic nitrogen reduction offers a vital approach for nitrogen fixation in a green and sustainable way, but the low solubility of nitrogen and the competitive hydrogen evolution reaction still impede its further development. Inspired by the structure of gas-trapping hydrophobic hair on a subaquatic spider and the function of hemocyanin in its blood, in the present work, an aerophilic-hydrophilic heterostructured electrode is constructed by using aerophilic ultrathin porous Bi5O7I nanotubes and hydrophilic carbon spheres. Besides, the electrolyte is functionalized with suspended ultrathin porous Bi5O7I nanotubes. The Faradaic efficiency is increased from 5.19 % to 13.42 %, and the ammonia yield is boosted from 7.96 to 31.46 mg h−1m-2 by the new way at -0.4 V versus reversible hydrogen electrode under ambient conditions. Furthermore, the highest yield rate of 85.45 mg h−1 m-2 is achieved with a configured flow cell. This work presents a promising biomimetic strategy to boost electrocatalytic N2 fixation proceed from electrode and electrolyte. © 2020 Elsevier B.V.