CoNi layered double hydroxides grown on Ag nanowires for high-efficient nitrate-to-ammonia conversion

Electrocatalytic reduction of nitrate to ammonia is a promising technology. The sluggish rate of the nitrate-tonitrite reduction is the core issue. By reducing the energy barrier of this step, the reactivity can be greatly promoted. Here, we have documented Co2Ni1 layered double hydroxide (LDH) on Ag nanowire (NW) that demonstrates efficient catalytic activity in electro-reducing nitrate to ammonia under a diverse set of application conditions. It achieves a high ammonia yield (2.50 mmol h(-l) cm(-2)) and Faradaic efficiency (99.6 %) at -0.7 V versus a reversible hydrogen electrode (VRHE). Through comparative experiments, it has been proven that the selective reduction of nitrate to nitrite on Ag NW is the key. This series of Ag NW heterostructure electrodes provides new insights into the design principles of high-performance and high-durability nitrate reduction electrodes under environmentally relevant wastewater conditions.