纳米TiO2在泡沫镍上的负载技术研究

Study on the load of nano-TiO_2 on nickel foam

采用溶胶-凝胶法制备了锐钛矿型晶体结构的纳米TiO2。以硅溶胶为无机粘结剂,分别采用在含纳米TiO2的乙醇悬浮液中浸涂和直接用悬浮液喷涂的方法,在泡沫镍载体上负载了TiO2催化剂,应用扫描电子显微镜(SEM)对硅溶胶涂层和纳米TiO2催化剂的负载状态进行了分析。研究结果表明,硅溶胶与泡沫镍结合牢固,涂层分布均匀。就TiO2的分散性和负载均匀性而言,喷涂负载优于浸涂负载。采用不同的喷涂次数,可以明显改变纳米TiO2在粘结剂表面的负载量和负载状态。当喷涂次数为1次时,负载的TiO2颗粒呈单分散状态;喷涂次数增加时,会出现纳米颗粒的堆积,但不同于浸涂时的团聚;喷涂5次时,纳米颗粒在泡沫镍表面形成密集层状分布。

Nano-TiO2 with anatase phase was synthesized by sol-gel process. Nickel foam was loaded with nano-TiO2 by dip coating in ethanol and nano-TiO2 suspension and spraying directly using the suspension, respectively,where the inorganic silica sol was used as the binder. The SEM was applied to characterize the coating and the loaded nano-TiO2 catalyst. The results showed that the silica sol coating was well adhered to the Ni substrate and distributing uniformly. The spraying is superior to dip coating from the dispersion and uniform load of nano-TiO2. The amount and distribution of loaded nano-TiO2 varied with the spraying time. Monodisperse nano-particles were gained when being coated one time, and the stack of nano-partieles appeared with the increase of coating time, but this was different from the aggregation caused by dipping. The dense and layered distribution of nano-TiO2 would be gained after spraying by five times.