TNAs的制备条件及可见光下GQDs/TNAs复合材料的性能初探

采用阳极氧化法制备了二氧化钛纳米管阵列（TNAs）,探索了制备条件对TNAs表面形貌结构的影响;并采用电泳法制备了石墨烯量子点/二氧化钛纳米管阵列（GQDs/TNAs）复合材料,以罗丹明B为目标降解物,初步考察了复合材料的光催化性能;进而通过X射线衍射（XRD）、X射线光电子能谱（XPS）、拉曼光谱、紫外-可见漫反射（UV-vis DRS）、电化学阻抗（EIS）和光电压响应等手段对其结构和光电学特征进行了分析。结果表明,氧化次数和电解液类型对TNAs排列的有序性具有显著影响,二次氧化时间、二次阳极电压和NH₄F质量分数对TNAs的管长、管径具有明显影响;适宜条件下GQDs的掺杂有助于提升TNAs的光催化性能,经120min的可见光照射后,制备的GQDs/TNAs复合材料对罗丹明B的降解率达到70.3%,较TNAs提高了19.7%,且具有良好的稳定性;光电学测试同样表明该GQDs/TNAs复合材料的光吸收效率和光电子转移能力较TNAs有明显提高。

Preliminary investigation of the preparation conditions of TNAs and performance of GQDs/TNAs composites under visible light

Titania nanotube arrays(TNAs) were prepared by electrochemical anodization, and the effects of preparation conditions on the surface morphology of TNAs were investigated. The graphene quantum dots titania nanotube arrays (GQDs TNAs) composites were prepared by electrophoresis, and the photocatalytic performance of the composites were investigated using Rhodamine B as a target degradant. Further, the structures and photoelectric characteristics of TNAs and GQDs/TNAs are analyzed by X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS), Raman spectroscopy, UV-vis diffuse reflectance spectroscopy(UV-vis DRS), electrochemical impedance spectroscopy(EIS), and photovoltage test. The results show that the number of oxidation and type of electrolyte have a significant effect on the orderliness of TNAs. The secondary oxidation time, secondary oxidation voltage and NH₄F mass fraction have a significant effect on the tube length and tube diameter of TNAs. The deposition of GQDs under suitable conditions helps to enhance the photocatalytic performance of TNAs. After 120 minutes of visible light irradiation, the degradation rate of Rhodamine B by GQDs/TNAs composites reached 70.3%, which was 19.7% higher than that of TNAs. And the composites have good stability. Photoelectricity tests also showed that the optical absorption efficiency and photoelectron transfer ability of the GQDs/TNAs composites were significantly higher than those of TNAs.