Carbon-doped boron nitride nanosheets: A high-efficient electrocatalyst for ambient nitrogen reduction

h-BN -based electrocatalysts with low-cost and high efficiency have a great potential for electrochemical nitrogen reduction reaction (NRR). The carbon-doped boron nitride ( C-BN ) nanosheets are proposed as the excellent metal-free electrocatalysts for converting nitrogen to ammonia (NH 3 ). In 0.1 M Na 2 SO 4 solution, it obtains NH 3 yield of 44.59 ± 1.79 μg h −1 mg cat −1 at − 0.9 V vs reversible hydrogen electrode (RHE), with a high faradaic efficiency (FE) of 13.27 ± 0.42 % at − 0.7 V vs RHE, and an outstanding electrochemical durability. Density functional theory (DFT) calculations reveal that carbon-doping dramatically reduces the band gap to 1.40 eV and induces charge accumulation on carbon atom to facilitate N 2 adsorption. The synergistic interaction of C and B atoms at the double-active-site of C-BN significantly decreases the energy barrier (from *NH-NH to *NH-NH 2 ) for the potential-determining step. The results confirm that C-BN has the potential as an efficient metal-free NRR electrocatalyst in neutral media. The NRR performance of h-BN can be dramatically improved by introducing C atoms. C-BN nanosheets can achieve a brilliant NH 3 yield of 44.59 μg h −1 mg cat −1 at − 0.9 V vs RHE in neutral media compared with h-BN (23.72 μg h −1 mg cat −1 ). • The carbon-doped boron nitride ( C-BN ) nanosheets exhibit a brilliant NH 3 yield and a superior FE in neutral media. • The carbon doping improves the electronic conductivity of pure h-BN dramatically. • The charge accumulation on carbon atom activates the N 2 molecule effectively and facilitates the subsequent NRR process.