Fig. 3: Electrochemical performance of catalysts.

\({{{\mbox{FE}}}}_{{{{\mbox{NH}}}}_{3}}\)and \({{{\mbox{FE}}}}_{{{{\mbox{NO}}}}_{2}^{-}}\) of NO₃⁻RR (a), bias-current density and products yield for NH₃ (b), and the ratio of NO₂⁻ to NH₃ generated (c) for different Cu/Co ratio at 0 V in 100 mM KNO₃ + 1 M KOH electrolyte (catalysts loading was 5 mg cm⁻²). \({{{\mbox{FE}}}}_{{{{\mbox{NH}}}}_{3}}\) (d) and NH₃ product yield (e) at different electrode potentials on Cu₅₀Co₅₀, pure Cu and pure Co catalysts modified Ni foam (catalysts loading was 5 mg cm⁻²). Comparison of the electrocatalytic NO₃^-RR performances of Cu₅₀Co₅₀ modified Ni foam with other extensively reported electrocatalysts (f). \({{{\mbox{FE}}}}_{{{{\mbox{NH}}}}_{3}}\) and \({{{\mbox{Yield}}}}_{{{\mbox{mass}}}-{{{\mbox{NH}}}}_{3}}\) on Cu₅₀Co₅₀/Ni foam under the applied potential of −0.2 V during 10 periods of 1 h electrocatalytic NO₃^-RR (g) (catalysts loading was 5 mg cm⁻²). The time-dependent concentration of NO₃⁻, NO₂⁻ and NH₃ and corresponding FE over Cu₅₀Co₅₀ modified Ni foam at −0.1 V (h) (catalysts loading was 5 mg cm⁻²). Error bars represent the standard deviations calculated from three independent measurements.