Zn-Co-TiO2纳米复合镀层的光生阴极保护特性

用纳米复合电沉积技术在低碳钢表面制备了Zn-Co-TiO₂纳米复合镀层。用SEM、EDS和XRD等技术手段对样品进行了分析与表征。结果表明,镀层中Ti02的含量约为12.63%,并均匀分散在镀层中,可以起到细化Zn-Co合金镀层晶粒的作用,并使Zn-Co合金镀层的耐蚀性能得到提高。用紫外光辅助照射电极电位监测方法研究Zn-Co-TiO₂纳米复合镀层光生阴极保护特性。结果表明,在紫外光照射下,镀层的电极电位负移,说明镀层具有光生阴极保护性能;关闭紫外光灯后,其电极电位正移,但仍低于镀层未光照前的电极电位。在400℃下氧化6 h后镀层表面生成了ZnO薄膜,其与TiO₂的协同作用可进一步提高镀层的光生阴极保护性能。

PHOTOGENERATED CATHODE PROTECTION PROPERTIES OF Zn-Co-TiO2 NANOCOMPOSITE COATINGS

Zn-Co-TiO₂ nanocomposite coatings were prepared by electrodeposition technique on mild steel. SEM,EDS and XRD examinations revealed that 12.63%TiO₂ nanoparticles were uniformly dispersed in the nanocomposite coating and refined the crystalline size,consequently,the corrosion resistance of Zn-Co alloy coatings was further improved.The photogenerated cathode protection properties of Zn-Co-TiO₂ nanocomposite coating were investigated by monitoring the electrode potential under ultraviolet（UV） illuminated conditions, The results showed the electrode potentials of Zn-Co-TiO₂ nanocomposite coating negatively shifted under UV illuminated,which indicated that Zn-Co-TiO₂ nanocomposite coating had photogenerated cathode protection properties;When the UV light was turned off,the electrode potentials shifted to the positive direction but were still lower than the initial electrode potential before UV illuminated;it was also found that the oxidation at 400℃for 6 h could further improve the photogenerated cathode protection properties and the reason for this is attributed to photogeneated cathode protection properties of ZnO layer generated on the surface and its synergy with TiO₂.