Two-dimensional ultrathin nanosheets over mackinawite FeS for efficient electrochemical N2 reduction

Electrocatalytic N-2 reduction reaction (NRR) has been considered as a promising and alternative strategy for the synthesis of NH3, which will contribute to the goal of carbon neutrality and sustainability. However, this process often suffers from the barrier for N-2 activation and competitive reactions, resulting in poor NH3 yield and low Faraday efficiency (FE). Here, we report a two-dimensional (2D) ultrathin FeS nanosheets with high conductivity through a facile and scalable method under mild condition. The synthesized FeS catalysts can be used as the work electrode in the electrochemical NRR cell with N-2-saturated Na2SO4 electrolyte. Such a catalyst shows a NH3 yield of 9.0 mu g<middle dot>h(-1)<middle dot>mg(-1) (corresponding to 1.47 x 10(-4) mu mol<middle dot>s(-1)<middle dot>cm(-2)) and a high FE of 12.4%, which significantly outperformed the other most NRR catalysts. The high catalytic performance of FeS can be attributed to the 2D mackinawite structure, which provides a new insight to explore low-cost and high-performance Fe-based electrocatalysts, as well as accelerates the practical application of the NRR.