基于数字全息术的镍在“H2 SO4＋SCN －”溶液中的电流振荡研究

摘要

文章通过数字全息术和电化学方法相结合研究了Ni︱“0．5 mol／L H2 SO4＋5 mmol／L SCN －”体系的阳极溶解过程．结果表明：在活化区，SO2－4从本体迁移到电极表面附近并与溶出的Ni（Ⅱ）形成盐膜；在预钝化区与钝化区的交界处，由于SCN －可能与Ni（Ⅱ）或者Ni（Ⅲ）形成配合物，电极表面不容易形成稳定的Ni（Ⅲ）氧化膜，造成镍表面膜的周期性生成和溶解，从而出现电流振荡现象．%In this paper ,the current oscillations of the Ni︱"0 .5 moL H2 SO4 +5 mmoL SCN -"system have been studied with the in‐line digital holography and the electrochemical methods .The results show :in the active region ,SO2 -4 ions move from the bulk solution to the surface of the electrode to form the salt film with the dissolved Ni(Ⅱ );in the prepassive region ,the SCN - ions form the clathrate with Ni (Ⅱ )or Ni (Ⅲ)easily and the oxide film is not formed easily on the surface of the electrode ,inducing the periodic for‐mation and dissolution of the surface film ,thus the current oscillations occur .