温和条件下合成锐钛型晶体TiO2纳米粒子及其在化学传感器方面的应用

Synthesis of Anatase TiO_2 Nanoparticles under Mild Conditions and Their Applications in Chemical Sensors

探索了使用简便的、绿色的、可控的方法在温和的条件下合成制备了结晶度非常好的锐钛型晶体TiO_2纳米粒子。此方法使用易得的异丙氧基钛(IV)化合物,在室温条件下水解4h,然后使用两种不同的后续处理方法,第一种处理方法,待水解完成后,将所生成TiO_2纳米粒子继续保留在反应的母液中,放置陈化4周后,经过离心分离,水洗纯化,再离心沉淀,室温干燥,得到最后产品。第二种处理方法,待水解后,立即离心分离,水洗纯化,室温干燥,然后在450℃的高温加热炉中热处理3h后,冷却得到白色粉末产品。这两种处理方法都成功制得结晶度非常好的锐钛型晶体TiO_2纳米粒子,扫描电镜(SEM)和X-射线粉末衍射(XRD)表征给出所得纳米粒子直径在7～10 nm。BET模型所测定的纳米粒子的比表面积分别是室温陈化的产品为265.2m2/g和高温450℃的产品为87.4m2/g,室温陈化的产品的比表面积大约是450℃高温处理的产品的3倍。SEM照片显示,此二种处理方法合成的产品的纳米粒子直径都非常小,对比SEM照片可知,相对于室温下,高温产品明显有团聚存在。经过选择特定的化学反应体系,对所合成的TiO_2纳米粒子光催化化学反应进行了测试,结果显示,所合成的产品具有很好的光催化特性,可应用于制备光催化的可逆的检验氧分子的化学传感器。

This paper explores the synthesis of anatase TiO2 nanoparticles with excellent crystallinity by using a simple, green and controllable method under mild conditions.This method uses readily available titanium （IV） isopropoxide compounds to hydrolyze at room temperature for 4 hours and then uses two different post-treatment methods, the first method of treatment.After the hydrolysis is complete, the resulting TiO2 nano Particles continue to remain in the reaction of the mother liquor, placed four weeks after aging, after centrifugation, washed with water, then centrifuged and dried at room temperature to give the final product.The second treatment, to be hydrolyzed, immediately centrifuged, washed with water, dried at room temperature, and then heat treatment in a 450 ~C high temperature furnace for 3 hours, cooled to give a white powder product.The anatase crystal TiO2 nanoparticles with good crystallinity were successfully prepared by both of these methods.Scanning electron microscopy （SEM） and X-ray powder diffraction （XRD） characterization gave the obtained nanoparticles with diameter of 7-10 nm.The specific surface area of the nanoparticles determined by the BET model is that the product aged at room temperature is 265.2 m2/g and the product at high temperature 450~C is 87.4 m2/g, the specific surface area of the product aged at room temperature is about 450~C, Times Scanning electron microscopy （SEM） photographs show that the diameters of the nanoparticles synthesized by the two processing methods are very small.Compared with the electron micrographs, it can be seen that the high-temperature products obviously agglomerate relative to room temperature.After selecting a specific chemical reaction system, the photocatalytic reaction of the synthesized TiO2 nanoparticles was tested.The results show that the synthesized product has good photocatalytic properties and can be applied to the preparation of photocatalytic reversible detection Oxygen molecular chemical sensor.