室温下超声波辐照制备介孔结构的TiO2及其光催化性能

在室温条件下,利用超声波辐照方法合成了一系列具有大比表面积的介孔结构TiO₂光催化剂。应用N₂-物理吸附、X射线粉末衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)等手段对合成的样品进行了表征。考察了超声波强度、发射时间对TiO₂的结晶度、比表面积、孔体积、孔径等物理结构的影响,并提出了超声波辐照下TiO₂的介孔结构的形成机理。以λ=365 nm的紫外光为光源,评价了该系列催化剂光催化降解染料甲基橙的性能。结果表明超声波功率的增加将增加TiO₂的结晶度和孔径,并使其晶粒发生细化,提高催化剂的分散性。声化学合成的样品具有较高的光催化活性,其主要原因是超声波辐照方法合成的TiO₂具有较高的结晶度和较大的比表面积和孔体积。 

Fabrication of TiO2 with mesoporous structures through ultrasonic irradiation at room temperature and their photocatalytic performances

A series of TiO₂ photocatalyst with well mesoporous structures and high crystallinities were rapidly fabricated by ultrasonic irradiation at room temperature.The prepared samples were characterized by physical adsorption of N₂,X-ray diffraction(XRD),scanning electron microscopy(SEM).and transmission electron microscopy(TEM).The effects of the power and time of the ultrasonic irradiation on the crystallinity,surface area,pore volume and pore size of the TiO₂ were investigated.The formation mechanism for the mesoporous TiO₂ photocatalyst under ultrasonic irradiation was proposed.The photocatalytic activity of the samples was evaluated by photocatalytic degradation of methylic orange under UV light(λ=365 nm) irradiation.The results showed that the increase of ultrasonic irradiation power will increase the crystallinity,pore size and dispersion of TiO₂ and decrease the size of the grain.A high photocatalytic activity was obtained in the ultrasonic fabricated samples,which could be attributed to the high crystallinity and high surface area and pore volume of the photocatalysts.