目的 研究稳定剂 NH₄HF₂ 对铁电结晶过程的影响。 方法 采用线性电位扫描伏安法、单电位阶跃计时电流法、电化学交流阻抗谱等技术,研究含不同浓度 NH₄HF₂ 的镀铁溶液中,铁在玻碳电极上的电沉积行为。 结果 随着 NH₄HF₂ 浓度的增加,铁沉积的阴极极化变小。 在-1 . 225 ~-1 . 300 V 阶跃电位范围内,铁在玻碳电极上的电结晶都遵循三维瞬时成核理论,稳定剂浓度的变化不会改变其成核机理。随着 NH₄HF₂ 浓度的增加,晶核垂直生长速率和双电层电容明显增大,溶液 / 电极界面电荷传递电阻显著降低,而溶液电阻呈小幅度降低。 结论 稳定剂 NH₄HF₂ 的加入可促进 Fe²⁺的电沉积,并提高晶核的垂直生长速率。

Objective To understand the effect of NH₄HF₂ on the cathodic process of iron electrodeposition. Methods Linear sweep voltammetry, single-potential step chronoamperometry and AC impedance spectroscopy were adopted to study the electrocrystallization of iron in plating solutions containing different concentrations of NH₄HF₂ . Results With the increase in the concentration of NH₄HF₂ , the cathodic polarization of iron electrodeposition was decreased; in the Step-potential range of-1. 225 ~-1. 300 V, the electrocrystallization of iron on glassy carbon electrode followed 3D instantaneous nucleation regardless of the concentration of NH₄HF₂ ; when the concentration of NH₄HF₂ increased, the outward growth rate of crystal nucleus and the double layer capacitance were enhanced, however the charge transfer resistance of solution / cathode interface was obviously decreased and the solution resistance was slightly declined. Conclusion The addition of NH₄HF₂ could accelerate the electrodeposition of iron and increase the outward growth rate of crystal.