Ni2P nanosheet array for high-efficiency electrohydrogenation of nitrite to ammonia at ambient conditions

Ni2P nanosheet array supported on nickle foam enables ambient electrochemical NO2– reduction to NH3, achieving a large NH3 yield rate of 2692.2 ± 92.1 μg h−1 cm−2 (3282.9 ± 112.3 μg h−1 mgcat.−1), a high Faraday efficiency of 90.2 ± 3.0%, and selectivity of 87.0 ± 1.7% at –0.3 V versus a reversible hydrogen electrode in 0.1 M phosphate buffer saline with 200 ppm NO2–.