高效光催化降解气相苯纳米TiO2微球的制备EI北大核心CSCD

以四氯化钛为钛源,尿素为沉淀剂前驱物,硫酸钠为分散剂,利用水热法在水-醇体系中制备出纳米TiO2微球。运用X射线衍射、电子显微镜、N2吸附-脱附和紫外-可见光谱等手段表征样品的结构和性质,并考察了水热温度对纳米TiO2微球结构及光催化降解气相苯活性的影响。结果表明,此类微球由纳米颗粒组成,且比表面积大,介孔结构明显,光吸收出现明显的“蓝移”。光催化结果显示,微球具有很高的光催化活性,尤其是180℃下制备的微球仅用20min将苯完全去除,但生成CO2的量仍随时间有所增加,表明微球的强吸附性能促进其光催化降解过程,且矿化率高达5.5,是P25(2.7)的2倍。

Preparation of nano-TiO2 microspheres with highefficiency in photocatalytic degradation ofgaseous benzene

The nano-TiO2 microspheres were prepared by a hydrothermal method with urea in ethanol/water solution in the presence of sodium sulfate.The prepared samples were characterized by X-ray diffraction,transmission electron microscopy,N2 adsorption-desorption and UV-Vis diffuse reflectance spectroscopy,the effects of hydrothermal temperature on the nano-TiO2 microspheres morphology were investigated,and the photocatalytic activities toward gaseous benzene of the samples were studied.The results indicate that the microspheres are composed of tiny nanoparticles,the TiO2 microspheres pose high specific surface areas and uniform porous nanostructures,the optical absorption edges of the samples have“blue shift”.The photocatalytic results confirm the benzene-degrading effectiveness of the TiO2 microspheres,especially,the results show that no benzene detected after20 min reaction with TiO2 microspheres prepared at 180℃,however,the produced CO2 concentration continues to increase,it indicates that TiO2 microspheres with very high adsorptive capacity can enhance the subsequent photocatalytic reaction,and the mineralization ratio of this TiO2 microspheres can be as high as 5.5,which is double of P25(2.7).