Aqueous electrocatalytic properties of nitrogen-doped carbon electrodes synthetized by innovative electrochemical process in molten NaCl-KCl

This work presents the development of CN X electrodes by simple electrooxidation of nitride ions (N 3− ) into nitrogen on carbon surface in molten eutectic NaCl-KCl at 750 °C with Li 3 N (2 mol kg 1 ) as nitrogen precursor. The influence of electrolysis parameters such as the N-amount doped, the electrodeposition rate and the thermic post-treatment applied was studied and electrocatalytic properties obtained were compared in aqueous solutions with Fe (II) /Fe (III) redox system at room temperature. It appears that increasing the amount of nitrogen deposited induced an increase of electrocatalytic properties with the record of highest current peak densities and the highest capacitive currents. Furthermore, decreasing the electrodeposition rate or apply a thermic post-treatment consisting of leaving the CN X electrode at 750 °C during 1 h, leaded to a decrease of capacitive current and an increase of electron transfer rate. • Electrooxidation of nitride ions into nitrogen on carbon surface in molten NaCl-KCl at 750 °C. • Study of influence of N-amount, N-electrodeposition rate and thermic post-treatment at 750 °C. • Characterization of CN X properties in aqueous solutions at room temperature.