PVP辅助水热法制备板钛矿TiO₂及光催化性能

PVP Assisted Hydrothermal Synthesis and Photocatalytic Properties of Brookite TiO₂

以聚乙烯吡咯烷酮(PVP)为辅助剂,采用水热法制备了板钛矿TiO2纳米颗粒。借助于多种测试仪器对所得样品进行了表征,如X射线衍射仪、拉曼光谱仪、扫描电镜、紫外漫反射光谱仪等。同时,在紫外光照射下,利用亚甲基蓝溶液降解实验评价了所得样品的光催化活性。实验结果表明,所得样品为单一相板钛矿TiO2纳米颗粒。PVP在板钛矿TiO2纳米颗粒形成过程中起到了稳定剂和分散剂作用。改变PVP用量,板钛矿TiO2的颗粒尺寸先减小后增大,禁带宽度值维持在3.2~3.3 eV范围内。PVP的最佳用量为0.2 g,该条件下所得板钛矿TiO2的纳米颗粒尺寸最小(约为21.0 nm),光催化活性最高,即在紫外灯照射120 min后,对亚甲基蓝溶液的降解率高达96.4%。

Brookite TiO2 nanoparticles were synthesized byhydrothermal method in the presence of polyvinylpyrrolidone (PVP) as auxiliaryagent. The samples were characterized by X-ray diffractometer, Ramanspectrometer, scanning electron microscope, UV diffuse reflectancespectrometer, etc. At the same time, the photocatalytic activity of the sampleswas evaluated by the photodegradation of methylene blue (MB) solution under UVlight. Experimental results show that all the samples are single-phase brookiteTiO2 nanoparticles. PVP plays a stabilizing and dispersing role inthe formation of brookite TiO2 nanoparticles. With the increase ofthe dosage of PVP, the particle size of brookiteTiO2 samples decreases first and then increases, while the band gapvalue remains in the range of 3.2~3.3 eV. The optimal dosage of PVP is 0.2 g,and the obtained brookite TiO2 nanoparticles under this conditionshow the smallest particle size (about 21.0 nm) and highest photocatalyticactivity, that is, the degradation rate of MB solution reaches 96.4% after UVirradiation for 120 min.