改性TiO2纳米管的制备及其对盐酸多西环素的降解

Preparation of Modified TiO Nanotubes and Photocatalytic Degradation of Doxycycline Hydrochloride

利用商业TiO2粉末,采用水热法制备出不同摩尔分数的Co^2+掺杂改性TiO2纳米管,以盐酸多西环素为降解目标,研究了样品的光催化性能。通过扫描电子显微镜(SEM)、投射电子显微镜(TEM)、比表面积仪(BET)、X射线衍射(XRD)、紫外-可见分光光度法(UV/Vis)等技术对样品进行了表征。结果表明,TiO2纳米管管径均一、管壁多层,具有两端开口的中空孔径结构;Co^2+掺杂不会对纳米管的形貌产生影响,但能够增大纳米管的比表面积;Co^2+以离子形式存在于TiO2纳米管的晶格内部;随着Co^2+掺杂量的增加,掺杂样品的吸收边出现了持续的红移。盐酸多西环素的光催化降解实验表明,相比TiO2粉末,TiO2纳米管具有较好的光催化活性,并且Co^2+掺杂改性提高了材料的光催化活性。其中,摩尔分数为1%的Co^2+掺杂改性的样品对盐酸多西环素的光催化降解效果最好,在氙灯照射下反应120 min,降解率为81.1%。

Co-Modified TiO2 nanotubes were prepared with a simple hydrothermal process using commercial titanium dioxide powder.The photocatalytic activities of samples were evaluated by the photocatalytic degradation of doxycycline hydrochloride.The samples were characterized by scanning electron microscope(SEM),projection electron microscope(TEM),specific surface area meter(BET)X-ray diffraction(XRD)and ultraviolet visible spectrophotometry(UV/Vis).The results showed that regularly uniform nanotubes were fabricated via the hydrothermal treatment and they have homogeneous multi-walled tubular structures and open ends.In terms of morphology,there is no significant difference after Co-doped treatment.However,in comparison with the pure TiO2 nanotube,Co-doped TiO2 nanotubes have larger surface area and high adsorbability.In addition,Co-doped TiO2 nanotubes greatly extend the absorption edge to the visible light region.The experiment about the photocatalytic degradation of doxycycline hydrochloride showed that degradation efficiency of TiO2 nanotube is higher than that of titanium dioxide powder and the photocatalytic activity of prepared samples increased with the added cobalt(Ⅱ)ions.The best degradation ratio can reach to 81.1%within 120 min under the irradiation of xenon lamp with a 1%doping.