Figure 4.

Electrochemical evaluation of as-prepared catalysts for NO₃RR

(A) Linear sweep voltammetry (LSV) at 5.0 mV s⁻¹ in 0.5 M K₂SO₄ with and without 0.1 M KNO₃, In 0.5 M K₂SO₄ and 0.1 M KNO₃ electrolyte: (B) corresponding Tafel plot of nitrate reduction kinetics; (C) Electrochemical impedance spectroscopy (EIS) with 5 mV alternating current amplitude at an applied potential of −0.6 V vs. RHE; (D) Double-layer capacitance (C_dl) measurement for determining electrochemically active surface area; (E) Faradaic efficiency (FE) and (F) yield rate of NH₃ as a function of overpotential for different catalysts. Error bars represent the standard deviation in yield rate and FE calculated after three tests for repeatability.