Defective carbon-doped boron nitride nanosheets for highly efficient electrocatalytic conversion of N2 to NH3

In industry, ammonia (NH3) is currently produced by Haber-Bosch technology, which suffers from the drawbacks of high energy consumption and CO2 emission. Artificial N2 fixation in aqueous solution under ambient conditions has been recently pushed forward by developing electrocatalysts with high efficiency and high selectivity for NH3 production. Herein, we demonstrate that defective carbon-doped boron nitride nanosheets (C-BN) show excellent electrocatalytic activity and durability in N2 fixation. To be used as a cathode catalyst, C-BN achieves an NH3 production rate of 36.7 μg h-1 mgcat-1 at -0.55 V vs a reversible hydrogen electrode (RHE), which is much higher than that of the synthesized and exfoliated boron nitride nanosheets. The faradic efficiency of C-BN attains 6.51% at -0.55 V vs RHE, which indicates excellent selectivity of the N2 reduction reaction (NRR). Furthermore, the catalysts show great stability during electrolysis and recycling tests. In principle, carbon doping and the defective structure contribute to the promoted NRR performance of C-BN.