Impregnation of silver in graphite carbon using solid reaction: Electrocatalysis and detection of 4-nitroaniline

In the present study, the proposed sensor was prepared by silver microparticles-impregnated carbon paste electrode (Ag-CPE) and used for electrocatalytic reduction of 4-nitroaniline (4-NA). The effect of the amount of silver into carbon paste on the peak potential shift was investigated. Electrochemical impedance spectroscopy (EIS) analyses were realized in the presence of [Fe(CN)6]3−/4− and KCl as a redox probe. The cell-electrolyte resistance (Rs), charge transfer resistance (Ret), and electron-transfer rate constant (kapp) were calculated for different modified electrode. The electrocatalysis of 4-nitroaniline by silver microparticles as a redox was studied in aqueous media at the surface of a carbon paste electrode using cyclic voltammetry (CV) and chronoamperometry methods. In addition to that, the Ag-CPE exhibits excellent electrocatalytic activity indicating that the modification with silver can greatly accelerate the electron transfer. The catalytic rate constant and diffusion coefficient for 4-nitroaniline were found to be 1.36 × 10−2 mol−1 L s−1 and 3.35 × 10−6 cm2 s−1 respectively.