Ag-TiO_2空心复合微球制备及其光催化性能

Preparation of Ag-TiO_2 hollow composite microspheres and their photocatalytic properties

为了提高空心TiO2的光催化活性和拓展其对可见光的响应,以聚苯乙烯为模板合成TiO2空心微球,再通过KBH4还原AgNO3,制备了TiO2空心壳层表面载有Ag单质粒子的复合微球。利用SEM、TEM、XRD和EDS对Ag-TiO2空心微球的形貌结构和组成进行表征,并以有机染料罗丹明B(RhB)为目标降解物,研究该复合微球的光催化性能。在紫外光下,载银量为2%的Ag-TiO2复合微球2h内对RhB的降解率比同条件下空心TiO2提高23.8%;在可见光下,载银量为2%的Ag-TiO2复合微球在6h内对RhB的降解率比同条件下空心TiO2提高28.2%。结果表明,壳层表面载有适量Ag单质粒子的空心TiO2复合微球,其光催化活性和对可见光的响应显著高于纯空心TiO2微球。

In order to improve the photo catalytic activity of TiO2 and expend its response to visible light,a com-posite sphere （Ag-TiO2 ）that contained Ag particles on the surface of TiO2 hollow shell was prepared through the redox reaction of AgNO3 with KBH4 using the surface treated polystyrene particles as templates.The com-posite,morphology and crystal structure of obtained Ag-TiO2 hollow spheres were characterized by SEM, TEM,XRD and EDS.The photo catalytic performance of Ag-TiO2 for Rhodamine B （RhB）degradation was in-vestigated under UV-Vis light irradiation.Under UV light irradiation,RhB degradation rate was increased by a-bout 23.8% within 2 h when Ag-TiO2 composite with molar ratio n（Ag）/n（Ti）of 2% were used compared with TiO2 hollow particles.Under visible light irradiation,RhB degradation rate was increased by about 28.2%within 6 h for Ag-TiO2 composite with molar ratio n（Ag）/n（Ti）of 2% compared with TiO2 hollow particles. Results show that TiO2 hollow shell containing an appropriate Ag particle can significantly improve the photo catalytic activity and expend TiO2 response to visible light.