恒电位模式下纯钛阳极氧化膜的形成及结晶特性

以传统的三电极阳极氧化体系为基础,以高纯钛片为工作电极,铂电极为对电极,饱和Ag/AgCl电极为参比电极,在0.1mol/L H2SO4溶液中,采用恒电位氧化法对高纯钛片进行了阳极氧化研究,考查了氧化电位以及氧化时间对TiO2薄膜的形成及结晶特性的影响,并利用扫描电镜-能谱仪,拉曼光谱仪和X射线光电子能谱仪等对所得到的钛表面阳极氧化膜进行了表征.结果表明,当氧化电位、氧化时间分别为6V、60min或者30 V、10min时,所得到的氧化膜中含有锐钛矿型TiO2纳米晶;提高阳极氧化电位、延长氧化时间均有利于钛的各种中间态氧化物向稳定性好的TiO2转化,并有利于阳极氧化膜中锐钛矿型TiO2纳米晶的形成和生长,最终致使氧化物薄膜由含少量纳米晶的短程有序结构转变成以锐钛矿相为主体的长程有序结构.

Formation and Crystallization Characteristics of Anodic Oxide Film on Pure Titanium in Potentiostatic Mode

The anodization of high-purity titanium was carried out via a potentiostatic approach in 0.1 mol/L H2SO4 solution,with a traditional three-electrode cell,a high-purity titanium plate,a platinum electrode and a saturated Ag/AgCl electrode respectively as the template,the working electrode,the counter electrode and the reference electrode.Then,the effects of anodization potential and oxidation time on the formation and crystallization characteristics of the anodic titanium oxide films were analyzed,and the films were characterized by means of SEM-EDS,Raman spectroscopy and XPS.The results show that there exist anatase-phase TiO2 nano-crystals in the films prepared via an anodic oxidation at 6 V,60 min or at 30 V,10 min,and that high anodization potential and long oxidation time both promote the transformation of intermediate titanium oxides to stable titanium dioxide and accelerate the formation and growth of the anatase-phase nano-crystals,thus resulting in a structural evolution of the anodic titanium oxide films from a short-range ordered structure with few TiO2 nano-crystals to a long-range one mainly composed of anatase-phase TiO2.