关键词: 铕, 化学修饰电极, Nafion薄膜, 计时库仑法

Abstract: Electrochemical behaviour of Eu(Ⅲ)-Oxine system at a Nafion polymer film electrode was studied by using single sweep voltammetry. The results showed that the electroreduction of Eu(Ⅲ)-Oxine complex in acetic buffer solution (pH5.6) at a Nafion film electrode appeared at about -0.93V(vs.SCE). Under an optimal condition, the peak current is proportional to the concentration of Eu(Ⅲ) in the range from 1.0×10^-7to 1.0×10^-5mol/L. Eu₂O₃ content inluminous material has been determined by this method. On the basis of the results of a series comparative experiments, the possible mechanism of electrochemical reaction of Eu(Ⅲ)Oxine complex has been proposed. Chronocoulometry was applied to determine the apparent diffusion coefficient of charge transportin polymer film and the mean of which is (2.0±0.4)×10^-11cm²/s.

Key words: seuropium, chemically modified electrode, Nafion film, chronocoulometry