An Ionic Liquid Bulk‐Modified Carbon Paste Electrode and Its Electrocatalytic Activity toward p‐Aminophenol

Abstract

AbstractAn ionic liquid bulk‐modified carbon paste electrode (M‐CPE) has been fabricated by using 1‐heptyl‐3‐methylimidazolium bromide as a modifier. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to evaluate the electrocatalytic activity of the proposed electrode by choosing p‐aminophenol (p‐AP) as a model compound. Both at a bare carbon paste electrode (CPE) and the M‐CPE, p‐AP yielded a pair of redox peaks in 0.1 mol·L−1 phosphate buffer solution (PBS, pH 7.0). At the CPE, the peak‐to‐peak potential separation (ΔEp) was 0.233 V, while at the M‐CPE the ΔEp was decreased to 0.105 V. Furthermore, the current response to p‐AP at the M‐CPE was 10.2 times of that at the CPE by DPV. The electron transfer rate constant (ks) of p‐AP at the M‐CPE was 13.3 times of that at the CPE. Under the optimal condition, a linear dependence of the catalytic current versus p‐AP concentration was obtained in the range of 2.0×10−6 to 3.0×10−4 mol·L−1 with a detection limit of 6.0×10−7 mol·L−1 by DPV. In addition, compared to other modified method the proposed electrode exhibited distinct advantages of simple prapartion, surface renewal, good reproducibility and good stability. It has been used to determine p‐AP in simulated wastewater samples.