Affiliation: | aGraduate School of Engineering, University of Fukui, Fukui-shi 910-8507, Japan bHubei Key Laboratory of Novel Reactor and Green Chemical Technology, School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan 430073, China cHubei Key Laboratory for Processing and Transformation of Agricultural Product, Wuhan Polytechnic University, Wuhan 430023, China |
Abstract: | The glassy carbon electrode coated with electropolymerized methyl-red film, 1.2 × 10−6 m in thickness, (PMRE) showed high sensitivity towards Hg(II) ions. PMREs were adopted to accumulate and detect Hg(II) ions in a pH 2.56 Britton–Robinson buffer solution. Cyclic voltammogram of the accumulated Hg species on PMREs exhibited an anodic wave at 0.64 V and a cathodic wave at 0.13 V, due to the oxidation of accumulated Hg species on PMREs and the reduction of Hg(II) ions in the solution, respectively. For this heterogeneous adsorption of Hg(II) ions onto PMREs, the maximum surface concentration, adsorption equilibrium, and Gibbs energy change were evaluated to be 5.12 × 10−6 mol m−2, 3.7 × 105 l mol−1, and −30.1 kJ mol−1, respectively. The anodic peak current at 0.64 V was linear with the concentration of Hg(II) ions in the range of 1.1 × 10−10 to 1.1 × 10−7 M with a detection limit of 4.4 × 10−11 M. The proposed method was utilized successfully for the detection of Hg(II) ions in the lake water. |