Ambient ammonia production via selective electroreduction of nitrite by NiCu@TiO2 nanoribbon array

Electrochemical nitrite (NO2−) reduction has the dual nature of alleviating NO2− pollution in water and converting it into beneficial ammonia (NH3). But highly active electrocatalysts are needed to overcome the slow kinetics of six-electron transfer. Herein, we report a nickel-copper bimetallic nanoparticle-decorated TiO2 nanoribbon array on a titanium plate (NiCu@TiO2/TP) as a high-efficiency catalyst for NH3 production. As expected, such an electrocatalyst displays a maximum Faradaic efficiency (FE) of 96.25% and a high NH3 yield of 688.97 μmol/h/cm2 at −0.5 V. Moreover, NiCu@TiO2/TP shows remarkable durability and stability during recycling tests. And the reaction mechanism is also investigated by theoretical calculations.