Direct electrocatalytic reduction of p-nitrophenol at room temperature ionic liquid modified electrode

Direct electrochemical reduction of p-nitrophenol (PNP) was investigated on a room temperature ionic liquid N-butylpyridinium hexafluorophosphate (BPPF(6)) modified carbon paste electrode (CILE). The cathodic peak potential was positively shifted and the peak currents were increased compared to that obtained on traditional carbon paste electrode (CPE). The results indicated that the presence of ionic liquid BPPF6 on the electrode surface showed excellent catalytic ability to the electrochemical reduction of PNP. The electrochemical behaviors of PNP on the CILE were investigated by cyclic voltammetry and the conditions such as the scan rate, the buffer pH, the substrate concentration were optimized. The electrochemical parameters were further calculated with the results of the electron transfer number (n), the charge-transfer coefficient (alpha) and the surface concentration (Gamma(T)) as 1.76, 0.37 and 2.47 x 10(-9) mol/cm(2), respectively, for the selected reductive peak. The results indicated that PNP showed an irreversible adsorption-controlled electrode process on the CILE. (C) 2008 Wei Sun. Published by Elsevier B. V. on behalf of Chinese Chemical Society. All rights reserved.