TiO_2-SA纳米光催化材料接枝动力学、结构及性能

Grafting Dynamics, Structures and Properties of Nano TiO_2-SA Photocatalytic Materials

采用后处理表面改性法在纳米TiO_2表面接枝水杨酸(SA)(TiO_2-SA),分别考察了超声搅拌、溶剂、物料比、p H值及温度等因素对接枝过程及光催化材料性能的影响,并研究了接枝反应动力学.通过傅里叶变换红外(FT-IR)光谱、X射线光电子能谱(XPS)、X射线衍射(XRD)等对TiO_2-SA纳米光催化材料进行了结构表征,并提出了结构模型.通过接触角测定、同步热分析(热重-差示扫描量热法(TG-DSC))、紫外-可见漫反射光谱(UV-Vis DRS)、扫描电子显微镜(SEM)对光催化材料进行了性能表征.结果表明,水杨酸改性纳米TiO_2可以提高疏水性及分散性,减缓在溶剂中的沉降速度,并能稳定吸附在油-水界面,实现了光谱响应范围向可见光的拓展.在紫外光照射下,TiO_2-SA表现出优异的光催化降解硝基苯性能.

Salicylic add （SA） was successfully grafted onto nano-1302 surfaces （TiO2-SA） by post-treatment surface modification. The effects of ultrasound stidng, solvents, material ratio, pH value, and temperature on the grafting process and photocatalytic material properties were investigated, and the grafting reaction kinetics was determined. The structures of the materials were determined using Fourier transform infrared （FT-IR） spectroscopy, X-ray photoelectron spectroscopy （XPS）, and X-ray diffraction （XRD）. A structural model was proposed. The properties of the photocatalytic material were examined using contact angle analysis, simultaneous thermogravimetry-differential scanning calorimetry （TG-DSC）, ultraviolet-visible diffuse reflectance spectroscopy （UV-Vis DRS）, and scanning electron microscopy （SEM）. Compared with bare TiO2, the modified TiO2 had good hydrophobicity and dispersion properties, a lower sedimentation velocity in solvents, better adsorption stability at oil-water interfaces, and extended visible light absorption. The TiO2-SA gave excellent photocatalytic performances in nitrobenzene degradation under ultraviolet-light irradiation.