Fig. 3: Electrocatalytic performance of ZnPc MDE for NO₃RR.

a LSV curves of NO₃RR performance with bare CNT, ZnPc MDE, and ZnPc AE. Scan rate, 20 mV s⁻¹. The inset shows their j_NH2OH at −0.55 V. R_u of CNT, ZnPc MDE and ZnPc AE are 4.9 ± 0.3 Ω, 4.8 ± 0.1 Ω, and 6.1 ± 0.8 Ω. b The FE values of various NO₃RR products at the applied potential of −0.55 V. c Schematic diagram shows the variation of the NO₃RR pathway on ZnPc MDE with different ZnPc loadings. The black ball represents the N atom, the pale blue ball represents the O atom, and the grey ball represents the H atom. The black items with hexagonal structures represent the CNT substrate, and the items with light blue molecular structure and orange center represent the ZnPc molecules. d FE(NH₂OH)s for NO₃RR by ZnPc MDE with varying Zn contents at −0.55 V. R_u of ZnPc MDE with metal content of 0, 0.3, 0.6 and 0.9 wt.% are 4.9 ± 0.3 Ω, 4.8 ± 0.1 Ω, 4.4 ± 0.1 Ω, and 4.3 ± 0.2 Ω. e The FE values of various NO₃RR products at different applied potentials by ZnPc MDE(H). f The NH₂OH production rate and j_NH2OH at different applied potentials by ZnPc MDE(H). All electrocatalysis measurements were conducted in an Ar-protected 1.0 M KOH + 1.0 M KNO₃ electrolyte. Three individual measurements were taken with various working electrodes, and the average (mean) values are presented with the standard deviation as error bars.