fig3

Figure 3. The exceptional electrochemical catalytic activity of the HS-LFP electrode toward nitrate reduction. (A) LSV curves of HS-LFP, LFP, and FP electrodes recorded in 1 M KOH and 1 M KOH + 0.1 M KNO₃; (B) Nyquist plots of HS-LFP, LFP, and FP electrodes; (C) Determination of double-layer capacitance from plots of capacitive current density versus scan rate; (D) Chronoamperometric curves of the HS-LFP electrode at different potentials in 1 M KOH + 0.1 M KNO₃; (E) Faradaic efficiency for NH₃ production on HS-LFP, LFP, FP electrodes at different applied potentials; (F) NH₃ yield rates of different electrodes as a function of applied potential; (G) Performance comparison with representative nitrate-to-ammonia electrocatalysts reported in the literature^[35-48]. Error bars represent the standard deviation of three independent measurements (n = 3). FP: FePO₄; LFP: LiFePO₄; FE: Faradaic Efficiency; LSV: linear sweep voltammetry.