Porous Cu nanosheets for efficient ammonia production via nitrate electroreduction

The electrochemical nitrate reduction (NO3RR) offers a promising alternative synthetic route for sustainable ammonia (NH3) production, effectively removing nitrate (NO3−) from wastewater under mild operating conditions. Copper (Cu) nanomaterials are considered to be effective catalysts for NO3RR. This study reports the simple synthesis of a porous Cu nanosheets via a two-step reaction, which are obtained from the electrochemical reduction of CuO nanosheets. The porous Cu nanosheets exhibit a high selectivity and activity for NO3RR, achieving an NH3 yield of 42.5 mg·h-1·mgcat-1 and a Faradaic efficiency of 97% for the conversion from NO3− to NH3 at the potential of −0.7 V (vs. RHE). The prominent electrocatalytic activity can be ascribed to porous architecture, high surface area, and low mass transfer resistance.