暴露(001)晶面的纳米TiO_2/SiC复合纤维气敏性能

Gas Sensing Properties of TiO_2/SiC Ultrafine Fiber with Exposed(001) Facet

锐钛矿相的TiO_2晶体主要由热力学稳定的(101)晶面组成,而具有较高活性的(001)晶面所占比例较少。通过F离子的引入,当其吸附在TiO_2的高活性(001)晶面上时,可以使晶面的表面能降低,从而制备出暴露(001)晶面的TiO_2。为提高该TiO_2的气敏性能,通过水热法将纳米TiO_2与SiC超细纤维复合,制备出具有分级结构的TiO_2/SiC复合纤维,以此解决TiO_2回收难及单晶TiO_2之间团聚的问题。结果表明,对于丙酮气体,所合成的TiO_2/SiC复合纤维的灵敏度(21.2)是暴露(001)晶面的纳米TiO_2灵敏度(14.0)的1.5倍,是商业TiO_2灵敏度(4.0)的5.3倍。

Anatase TiO2 is mainly composed by thermodynamically stable(101)facet with a low proportion of highly active(001).When fluorinion was absorbed on the highly active(001)facet,the surface energy of(001)reduced,which can help produce TiO2 with high proportion exposed in(001).To improve gas sensing properties,we compounded nanocrystal TiO2 and SiC ultrafine fiber by hydro-thermal reaction,and this method can solve two problems(recycle and aggregation).The results show that the sensitivity(21.2)of the synthesized TiO2/SiC ultrafine fiber is 1.5 times that of the TiO2 sensitivity(14.0)with exposed(001)facet,which is 5.3 times of the commercial TiO2 sensitivity(4.0)for acetone gas.