Accelerating electrosynthesis of ammonia from nitrates using coupled NiO/Cu nanocomposites

Herein, we report a nanocomposite electrocatalyst with coupled Cu and NiO, showing a high Faraday efficiency of 97% and excellent ammonia production rate (450 mg h^-1 cm^-2) for nitrate reduction. In situ UV-vis spectroscopic studies confirmed that the synergy between NiO and Cu could avoid NO₂^- enrichment and promote tandem nitrate reduction to ammonia synthesis.