Fabricating freestanding electrocatalyst with bismuth‐iron dual active sites for efficient ammonia synthesis in neutral media

Abstract

Abstract Electrocatalytic N 2 reduction (NRR) has been regarded as a promising approach for environment‐friendly and sustainable ammonia (NH 3 ) synthesis. However, developing cost‐effective electrocatalysts with high NRR efficiency at low overpotential in neutral media remains a great challenge. In this paper, a freestanding NRR electrocatalyst, BiFeO/FCC, has been developed by in situ growth of bismuth ferrite (Bi 25 FeO 40 ) on functionalized carbon cloth (FCC), which exhibits high NRR activity with a maximum NH 3 yield of 3.88 μg h −1 cm −2 (at −0.40 V vs. reversible hydrogen electrode [RHE]) and a Faradaic efficiency of 12.71% (at −0.45 V vs. RHE) in 0.1 M Na 2 SO 4 . The synergistic effect of the abundant exposed bismuth and iron dual active sites confined in the lattice, the binder‐free nature of the electrode and the excellent conductivity of the carbon substrate enable the easy adsorption/activation of N 2 and accelerate the electron transfer simultaneously, thus boosting its NRR performance. This work is significant to design low‐cost, and high‐efficient NRR catalysts for large‐scale electrocatalytic NH 3 synthesis.