Prussian blue/ superactivated carbon composite-modified electrode for detection of <em>p</em>-phenylenediamine

Abstract

A novel approach for the selective determination of <em>p-</em>phenylenediamine in aqueous solution using Prussian blue (PB)/ superactivated carbon (SAC) composite-modified glassy carbon electrodes is reported. The chemical constitution and microstructure of PB/SAC composites are studied by SEM, BET and IR data. Due to its unique structure and properties originating from Prussian blue in the superactivated carbon frame, PB/SAC composites show high electrocatalytic activity towards the oxidation of <em>p-</em>phenylenediamine. A special chemical reaction and electron transfer process on the surface of PB/SAC composite-modified GC electrode is proposed and evaluated by cyclic voltammetry and AC impedance in the presence of <em>p</em>-phenylenediamine. The current value of differential pulse voltammetry increases linearly with the <em>p-</em>phenylenediamine concentration in the range 2×10^-7−1×10^-3M with a detection limit of 6.47×10^-8 M (<em>S</em>/<em>N</em> = 3). The relative standard deviation of the waste water samples is < 6% and the recovery rate is 97−104%. These results suggest that the modified electrode has high selection for <em>p-</em>phenylenediamine, good repeatability, and operational stability. The modified electrode has been successfully used to analyze the amount of <em>p</em>-phenylenediamine in water samples.