钛片真空热氧化制备二氧化钛纳米线

Titania nanowires synthesized by thermal oxidation of Ti plates in vacuum

对经过不同预处理的钛片进行真空热氧化处理,在表面原位制得了TiO2纳米线。利用场发射扫描电子显微镜(FE-SEM)、高分辨透射电子显微镜(HR-TEM)和X射线衍射仪(XRD)对原位制备的TiO2纳米线的表面形貌及相结构进行表征,并通过降解水中染料罗丹明B的方式对经不同时间热氧化处理后酸洗钛片的光催化性能进行测试。薄膜结构表征结果表明,一定真空条件下钛片750℃热氧化5～10 h后可以获得大量直径40～50 nm,长度3.0～5.0μm的单晶金红石结构TiO2纳米线;使用H2 O2氧化钛片表面预先获得一层多孔非晶TiO2薄层显著影响纳米线的生长。光催化性能测试结果表明,真空热氧化处理1 h获得的扁平片状纳米结构金红石具有最高的光催化降解罗丹明B的能力;处理时间从5 h延长到10 h,得到的纳米线金红石薄膜的光催化性能提高。

A simple synthesis method of titania nanowires on metallic Ti plates by thermal oxidation in vacuum was reported.The surface morphology and phase structure of the titania nanowires were characterized by field-emission scanning electron microscopy（FE-SEM）,high resolution transmission electron microscopy（HR-TEM） and X-ray diffraction（XRD）.The photocatalytic efficiency to assist decomposition of rhodamine B in water for the Ti plates subjected to the vacuum thermal oxidation for various durations were also studied.It is found that single-crystalline rutile nanowires with average diameters of 40-50 nm and lengths of 3.0-5.0 μm grow from the Ti substrate after thermal oxidation in vacuum at 750 ℃ for 5-10 h.A porous and amorphous titania thin layer on the Ti substrate,which is achieved by H2 O2-oxidation,significantly influences the nanowire growth.The photocatalytic activity evaluations reveal that the plate-like rutile formed by thermal oxidation of Ti plates in vacuum at 750 ℃ for 1 h exhibits the highest activity.Prolonged the oxidation time from 5 h to 10 h,the photocatalytic activity of the rutile nanowires increases.