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 (NH3). In 0.1 M Na2SO4 solution, it obtains NH3 yield of 44.59 +/- 1.79 mu g h-1 mgcat -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 N2 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-NH2) for the potential-determining step. The results confirm that C-BN has the potential as an efficient metal-free NRR electrocatalyst in neutral media.

Automated summary

The carbon-doped boron nitride (C-BN) nanosheets show great potential as low-cost and efficient electrocatalysts for electrochemical nitrogen reduction reaction (NRR) to convert nitrogen into ammonia (NH3). Experimental results demonstrate that C-BN exhibits high faradaic efficiency and outstanding electrochemical durability in neutral media. Density functional theory (DFT) calculations reveal that carbon-doping reduces the band gap and facilitates N2 adsorption, while the synergistic interaction of carbon and boron atoms at the double-active-site significantly decreases the energy barrier for the potential-determining step.