Oxygen vacancies in Co3O4nanoarrays promote nitrate electroreduction for ammonia synthesis

Oxygen vacancy-enriched Co 3 O 4 nanosheet arrays enable ambient electrosynthesis of NH 3 via nitrate reduction, achieving a faradaic efficiency of 96.9% and a NH 3 yield of 12 157 μg h −1 cm −2 in 0.1 M NaOH with 0.1 M NO 3 − .