不同电解液组成对TiO2纳米管形成的影响

电解液在阳极氧化中发挥着重要作用,对TiO2纳米管的形成与否,形成后管的成分、形貌都有着很大的影响.本实验采用了恒压阳极氧化方式,分别以HF(0.5wt%),(NH4)2SO4 HF(0.5wt%),(NH4)H2PO4 HF(0.5wt%),NaNO3 HF(0.5wt%)为电解液,在钛箔表面获得多孔TiO2膜.用FESEM观察了多孔膜的形貌并用EDX和XPS能谱对膜表面成分和构成进行测试分析.实验结果表明:在单一的HF酸电解液中加入(NH4)2SO4或(NH4)H2PO4后,阳极氧化生成的膜孔径明显减小,并且膜表面形态较差.加入NaNO3后,对膜的形貌影响不是很大.由EDX和XPS能谱分析得出,阴离子中的大部分非金属元素较难进入膜表面,而氮元素却很容易掺杂进入膜的表面形成N-Ti-O结构,从而影响膜的成分构成.这表明本实验利用简单电化学方法实现了N的掺杂.通过XRD测试得出,含不同阴离子的电解液对TiO2膜的晶型转变温度影响不大.

Effect of Electrolyte on Morphology of TiO2 Porous Film on Pure Titanium

The electrolyte plays an important role in the formation and composition of TiO_2 porous films on pure titanium during anodic oxidation.The TiO_2 porous films were prepared by constant voltage anodic oxidation on the surface of pure titanium,using HF((0.5wt%)),(NH_4)_2SO_4 +HF(0.5wt%),(NH_4)H_2PO_4 + HF(0.5wt%),NaNO_3+ HF(0.5wt%) as electrolyte respectively.Then the morphology and the composition of the films were analyzed by the means of FESEM and EDX.It was found that the pore diameters of TiO_2 porous films reduced evidently with hydrous titanic oxide on the film surface when adding(NH_4)_2SO_4 or(NH_4)H_2PO_4 into the electrolyte containing HF(0.5wt%) only.The results of EDX and XPS show that we can use the electrochemical strategy to incorporate nitrogen in nanostructure TiO_2 porous films.Moreover,XRD analysis indicates that electrolytes containing different anions have little influence on the transition temperature of crystallization.