暴露高能晶面TiO_2空心微球的制备及其光催化性能

Fabrication of TiO_2 hollow microspheres with exposed high energy facet and influence on photocatalytic activity

目前二氧化钛(TiO_2)空心微球制备方法主要为模板法,步骤繁琐,模板难去除。采用一步水热法制备暴露(001)晶面的TiO_2空心微球,水热温度为200℃,水热时间12h,通过改变氟和钛的物质的量的比来控制TiO_2的形貌。采用XRD、FESEM、TEM、EDS等方法对样品的晶体结构、微观形貌进行表征。以罗丹明B为模拟污染物,采用紫外分光光计测定污染物的吸光度,评价了样品紫外光光催化降解罗丹明B的活性,当氟和钛的物质量的比值为2时,制备得到具有暴露(001)晶面的TiO_2空心微球,并且表现出了最佳的光催化活性。光催化反应40min,对10mg/L的罗丹明B的降解率达到95%。

At present,the most preparation method of titanium dioxide hollow microsphere is the template method,which have some obvious disadvantages,including the tedious procedures and the difficulty to remove the template.TiO2 hollow microspheres with highly energetic（001）facets exposed were prepared by a one-step hydrothermal strategy using ammonium bifluoride（NH4HF2）as a crystal face controlling agent.The amount of the nominal molar ratios of fluorine to titanium could control the morphology of TiO2 and the hydrothermal synthesis was conducted at 200℃for 12 hin a vacuum oven.The samples were characterized by X-ray diffraction（XRD）,field emission scanning electron microscope（FESEM）,transmission electron microscopy（TEM）,energy dispersive spectroscopy（EDS）to analyze its crystal structure and microstructure.The photocatalytic activity of samples was evaluated by photocatalytic decolorization of rhodamine B aqueous solution.The sample was prepared with the nominal molar ratios of fluorine to titanium for 2that showed hollow microsphere structure with highly energetic（001）facets exposed and even revealed the best photocatalytic activity.The best result indicated that the degradation rate of TiO2 achieved 95% at forty minutes.