不同基材上TiO_2膜的表征和光催化活性评价

Characterization and Photocatalytic Activity of TiO_2 Films Loaded on Different Substrates

采用溶胶 凝胶法在平行条件下制备了负载于钛、铝、不锈钢和玻璃等不同基材上的TiO2 浸渍提拉膜 ,利用原子力显微镜、俄歇电子能谱、X射线衍射、漫反射紫外 可见光谱和苯甲酰胺光催化降解等手段对TiO2 膜进行了表征和催化活性评价 .实验结果表明 ,基材的种类对TiO2 膜的性能有较大影响 ,各膜样品虽均为锐钛矿晶型 ,但表面形貌显著不同 .TiO2 /Ti,TiO2 /steel,TiO2 /Al和TiO2 /glass上TiO2 的平均粒径分别是 15 2 ,2 0 5 ,2 4 1和 4 7 7nm ,且前两者的粒径分布较为集中 .TiO2 /Ti和TiO2 /Al样品表面仅有Ti和O元素存在 ,而TiO2 /steel和TiO2 / glass表面则分别检测到有Fe和Na,Ca及Si等基材元素渗出 .各膜样品对苯甲酰胺光催化降解的活性次序是 :TiO2 /Ti>TiO2 /Al>TiO2 / glass>TiO2 /steel.根据实验结果可以推测 ,在焙烧阶段各基材上前驱体膜烧结行为的不同以及基材元素的渗出是造成不同基材上的TiO2 膜在表面形貌、化学组成、光吸收性能以及光催化活性方面存在明显差异的主要原因 .

The TiO 2 films loaded on Ti, Al, stainless steel and glass substrates were prepared by the dip-coating method from the Ti(OC 4H 9) 4 precursor. The surface morphology, chemical composition, crystalline property, photoabsorption capacity and photocatalytic activity of the TiO 2 films were characterized by atomic force microscopy (AFM), Auger electron spectroscopy (AES), X-ray diffraction (XRD), diffuse reflectance ultraviolet-visible spectroscopy (UV-Vis) and phtotocatalytic reaction experiments. The TiO 2 films loaded on different substrates show different properties and all TiO 2 films are of anatase. The mean TiO 2 particle size of TiO 2/Ti, TiO 2/steel, TiO 2/Al and TiO 2/glass is 15.2, 20.5, 24.1 and 47.7 nm, respectively, and that of TiO 2/Ti and TiO 2/steel has narrow distribution. Only Ti and O were detected on the surface of TiO 2/Ti and TiO 2/Al, while substrate elements such as Fe, Na, Ca and Si were proved to exist on the surface of TiO 2/steel and TiO 2/glass. The films have similar absorption capacity in the UV range, and the photocatalytic activity for the benzamide degradation decreases in the order TiO 2/Ti>TiO 2/Al>TiO 2/glass>TiO 2/steel. Based on these experimental results, it can be considered that the agglomeration of the precursor films and the transference of substrate elements in the calcination stage cause the difference in properties of the TiO 2 films loaded on different substrates.