Nano‐Ferric Oxide Embedded in Graphene Oxide: High‐performance Electrocatalyst for Nitrogen Reduction at Ambient Condition
Fei Wang, Lixue Xia, Xin Li, Weixiang Yang, Yan Zhao, Jian Mao
Abstract
Nitrogen (N 2 ) fixation at ambient condition by electrochemical N 2 reduction reaction (NRR) is energy‐efficient and eco‐friendly as compared to the traditional Harber–Bosch process, but it is extremely challenging. Development and design of high‐performance NRR electrocatalysts are indispensable to achieve the goal. In this work, a strongly coupled hybrid of nano‐Fe 3 O 4 with reduced graphene oxide (rGO) is synthesized via an in situ redox hydrothermal approach, and the synthesized Fe 3 O 4 @rGO hybrid has excellent activity, selectivity, and stability as an NRR catalyst. The NH 3 yield rate of 28.01 μg h ‐1 mg ‐1 at −0.3 V and the Faradaic efficiency (FE) of 19.12% at −0.1 V are obtained in 0.1 M Na 2 SO 4 solutions at ambient conditions. The superior NRR performance is attributed to the chemical coupling effect between rGO and nano‐Fe 3 O 4 particles, which leads to the enhancement of the binding affinity to N 2 molecules, improvement of the conductivity, and lowering the free energy of reaction for the limiting reaction step. This work provides a facile route in fabricating hybrid NRR catalysts with superior performance and shed lights on the reaction mechanism with theoretical mechanistic calculations.