以PVP为软模板构建的层状介孔TiO_(2)及其光催化性能

Construction of Layered Mesoporous TiO_(2)Using PVP as Soft Template and Its Photocatalytic Performance

以聚乙烯吡咯烷酮(PVP)为软模板、硫酸钛为钛源,采用无机沉淀-胶溶法制备了层状介孔PVP-TiO_(2)。采用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、紫外可见吸收光谱(UV-Vis-Abs)、比表面积分析仪(BET)分别对样品的表面形貌、晶相组成、紫外吸收带边、比表面积和孔结构进行了表征分析,对层状结构的形成机理进行了研究。以甲基橙为目标降解物,研究了样品的光催化性能。结果表明:在相同条件下,PVP-TiO_(2)对甲基橙的最佳降解率达到93.84%,明显高于纯TiO_(2)。经PVP改性后,TiO_(2)试样出现了层状介孔结构,结晶度和晶粒尺寸均减小,促进了锐钛矿向金红石相的转变,并且PVP的引入使得TiO_(2)的光吸收带边发生了一定的蓝移。

The layered mesoporous PVP-TiO_(2)was prepared by inorganic precipitation-peptization method using titanium sulfate as titanium source and polyvinylpyrrolidone as soft template.The surface morphology,crystal phase composition,ultraviolet absorption band edge,specific surface area and pore structure of the samples were characterized by scanning electron microscopy(SEM),X-Ray diffractometer(XRD),ultraviolet visible absorption spectrum(UV-Vis-Abs),and specific surface area meter(BET),respectively.The formation mechanism of layered structure was studied as well.The photocatalytic properties of the samples were studied by using methyl orange as the target degradation product.The results showed that the best degradation rate of methyl orange by PVP-TiO_(2)reached 93.84%,which was significantly higher than that of pure TiO_(2)under the same conditions.After TiO_(2)was modified by PVP,layered mesoporous structure was formed,and the crystallinity and grain size were decreased,promoting the transition from anatase to rutile crystal.In addition,the introduction of PVP made a blue shift of the light absorption band edge of TiO_(2).