磁场与卤素离子作用下Fe/NaHCO_3体系的阳极过程

EFFECT OF MAGNETIC FIELD ON ANODIC POLARIZATION BEHAVIOR OF Fe IN SODIUM BICARBONATE SOLUTION CONTAINING HALIDE IONS

Fe在NaHCO3 稀溶液中出现Ⅰ、Ⅱ两处阳极电流峰 ,分别对应电极 /溶液界面形成的较低价态Fe化合物与较高价态Fe化合物对Fe溶解的抑制作用 .单一磁场使电流峰值Ⅰ、Ⅱ处对应的电位正移、电流密度增大 ,还使钝化区起始电位正移 ,但对维钝电流密度以及过钝化电位影响较小 .单一Cl-或Br-对峰Ⅰ电位与电流密度影响较小 ,但使峰Ⅱ电流密度及维钝电流密度显著增大 ,且使过钝化电位大幅度负移 .磁场与Cl-或Br-共同作用时峰Ⅰ、峰Ⅱ及钝化区起始电位正移 ,峰Ⅰ、峰Ⅱ以及维钝电流密度均增加 ,过钝化电位负移 .Cl-与Br-浓度达 0 0 1mol/L时 ,外加磁场后阳极电流随电位变正而上升 。

In the absence of magnetic field and halide ion,there are two anodic current peaks (Ⅰ and Ⅱ) in the anodic polarization curve for Fe in dilute NaHCO 3 solution.In the absence of halide ion,the magnetic field resulted in a noble movement of the potentials at peaks Ⅰ and Ⅱ as well as the initial potential for passive range and an increase of the peak current densities,and the current densities in the passive range and the transpassive potential were little affected by the magnetic field.In the absence of magnetic field,addition of halide ions(Cl - or Br -) caused an increase of the current density at peak Ⅱ and the current density in the passive range,a negative movement of the transpassive potential,but little change of the potential and current density at peak Ⅰ.In the presence of the magnetic field,potentials at peaks Ⅰ and Ⅱ as well as the initial potential for passive range moved in the noble direction ,current densities at peaks Ⅰ and Ⅱ and in the passive range increased,and the transpassive potentials lowered in solutions containing low concentration of halide ions.However,current density increased monotonically with potential and current peaks and passive range disappeared when the concentration of halide ions reached 0.01mol·L -1 in the presence of the magnetic field.