原始喷涂粉末经过喷雾干燥法造粒,采用等离子喷涂工艺在普通载玻片上制备了纳米TiO2涂层,并对涂层在300℃,400℃,500℃进行热处理.采用X射线衍射(XRD)方法对TiO2涂层进行了相结构分析;用扫描电子显微镜(SEM)、透射电子显微镜(TEM)观察涂层的微观形貌;用压汞方法测量涂层的孔隙率.结果表明,喷涂后锐钛矿型TiO2含量大约在30%-50%,粒径10-30 nm,孔隙率小于6%,热处理后涂层更致密,孔隙率降低.喷涂电流为400A且未经过热处理的TiO2涂层具有最佳光催化效果.
The starting nano-TiO2 feedstock was agglomerated by spray-drying process. Nano-TiO2 coatings on transparent glasses were prepared by plasma spraying. The coating proceeded heat treatment at 300℃, 400℃ and 500℃ respectively. The phase structure and the morphology of the TiO2coatings were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM). The porosity of the TiO2 coatings was tested by mercury porosimetry method. The result shows that the content of anatase TiO2 in the sprayed coatings is approximate to 30% - 50% , and its grain size is about 10 - 30 nm. The porosity of the TiO2 coatings is less than 6% , but has a great influence to the photocatalytic properties. After heat treatment at 300℃ ,400℃ and 500℃ , the coating becomes denser and has a lower porosity, which leads to a decrease in photocatalytic properties. Sprayed nano-TiO2 coating obtained without heat treatment at the spraying current of 400 A has the best photocatalytic property.