Industrial production of NH₃ from N₂ and H₂ significantly relies on Haber-Bosch process, which suffers from high energy consume and CO₂ emission. As a sustainable and environmentally-benign alternative process, electrochemical artificial N₂ fixation at ambient conditions, however, is highly required efficient electrocatalysts. In this study, we demonstrate that hexagonal boron nitride nanosheet (h-BNNS) is able to electrochemically catalyze N₂ to NH₃. In acidic solution, h-BNNS catalyst attains a high NH₃ formation rate of 22.4 μg·h^-1·mg^-1_cat. and a high Faradic efficiency of 4.7% at -0.75 V vs. reversible hydrogen electrode, with excellent stability and durability. Density functional theory calculations reveal that unsaturated boron at the edge site can activate inert N₂ molecule and significantly reduce the energy barrier for NH₃ formation.

Development of earth-abundant electrocatalysts, particularly for high-efficiency hydrogen evolution reaction (HER) under benign conditions, is highly desired, but still remains a serious challenge. Herein, we report a high-performance amorphous CoMoS₄ nanosheet array on carbon cloth (CoMoS₄ NS/CC), prepared by hydrothermal treatment of a Co(OH)F nanosheet array on a carbon cloth (Co(OH)F NS/CC) in (NH₄)₂MoS₄ solution. As a three-dimensional HER electrode, CoMoS₄ NS/CC exhibits remarkable activity in 1.0 M phosphate buffer saline (pH 7), only requiring an overpotential of 183 mV to drive a geometrical current density of 10 mA·cm^–2. This overpotential is 140 mV lower than that for Co(OH)F NS/CC. Notably, this electrode also shows outstanding electrochemical durability and nearly 100% Faradaic efficiency. Density functional theory calculations suggest that CoMoS₄ has a more favorable hydrogen adsorption free energy than Co(OH)F.