等离子喷涂纳米TiO2涂层及其光催化性能

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400A且未经过热处理的TiO₂涂层具有最佳光催化效果.

Plasma spraying of the nano-structured TiO2 coatings and its photocatalytic properties

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 TiO₂ coatings 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.