Ambient Electroreduction of Nitrite to Ammonia over Ni Nanoparticle Supported on Molasses-Derived Carbon Sheets

Electrochemical nitrite (NO2–) reduction is a promising approach for ambient ammonia (NH3) synthesis and simultaneous mitigation of NO2– contaminant in wastewater. Herein, we report Ni nanoparticle supported on molasses-derived carbon sheets (Ni@MDC) as an earth-abundant electrocatalyst for NO2–-to-NH3 conversion. When tested in alkaline solutions with 0.1 M NO2–, such Ni@MDC obtains a high NH3 yield of 6.3 mg h–1 mgcat–1 with a Faradaic efficiency of 65.4% at −0.8 V versus reversible hydrogen electrode under ambient conditions. Furthermore, it shows remarkable electrochemical stability during long-term electrolysis and cycling tests.