模板水热法纳米TiO2制备及光催化性能研究

以聚乙烯吡咯烷酮(PVP)为模板剂,钛酸四正丁酯(TBOT)为钛源,水热法制备纳米TiO2。采用XRD,SEM、TEM和UV-Vis DRS等测试手段对其形貌和结构进行表征。通过对甲基橙的光催化降解实验,探讨了焙烧温度、催化剂用量和溶液pH值对光催化性能的影响。结果表明,TiO2具有锐钛矿相,平均晶粒尺寸约为23.2 nm,TiO2颗粒呈片层状或由片层状堆积的疏松圆球形,经超声后即分散为八面体晶粒。550℃焙烧的样品,紫外光照3 h后,对甲基橙的降解率可达84.2%。相比普通水热法,采用模板剂法制得的TiO2吸收带发生红移,因而也具有较好的可见光催化活性。

Preparation and photocatalytic properties of nano-TiO2 by hydrothermal method with template

Using polyvinylpyrrolidone(PVP)as template and tetrabutyl titanate(TBOT)as titan-ium source,nanosized TiO2 was prepared by hydrothermal method.The morphology and stru-cture of products were characterized by XRD,SEM、TEM and UV-Vis DRS.The photocatal-ytic efficiencies of nano-TiO2 were assessed by monitoring the photodegradation of methyl orange.Furthermore,the influences of calcination temperature as well as the amount of catalyst and the pH value of methyl orange solution on their photocatalytic properties were investigated.The results showed that nanosized TiO2 appear anatase phase and its average grain diameter is about 23.2 nm.The TiO2 particles present loose round shape ccumulated by lamellar structure and were scattered for the octagonal TiO2 nanocrystals under the ultrasonic.The photo-degradation rate of methyl orange by anatase TiO2 is 84.2%when illuminated for 3 h by UV source.However,the TiO2 doped by PVP led to a bandgap and obvious visible response comparing with the pure TiO2.