Research On Catalysts Of V-shaped Flame Pyrolysis Of Carbon Nanotubes

Carbon nanotubes (CNTs) as a new type of carbon materials has the very good mechanical properties, the unique physical and chemical, electrical properties and strong thermal stability.It has a potential application value in the electronic materials, composite material strengthening agent, hydrogen storage. Synthetic carbon nanotubes required three elements of:carbon sources, heat source, catalyst. And catalyst has a core function, the category and performance of catalysts directly determine the synthetic production and morphology of carbon nanotubes.In this article, the V-type pyrolysis flame synthesis method of carbon nanotubes, from the perspective of catalyst, the Fe (CO)5and Fe-Mo double metal oxide did catalytic synthesis of carbon nanotubes. We mainly inspected the synthesis temperature, sampling method, sampling time, gas concentration and the catalyst preparation conditions.In order to get a great deal of a single, diameter even, and the form of small diameter CNTs for the purpose, we obtained the best experimental condition.The results showed that:the Fe (CO)5did catalyst, external substrate sampling got ideal effect, carbon nanotubes yield and morphology is better, but generally larger diameter. And Fe (CO)5internal sampling got small diameter of carbon nanotubes, the most fine pipe diameter of8～10nm, but the tube production is low. Fe (CO)5internal sampling best experimental condition was:synthesis temperature950℃, CO flow0.4L/min, sampling time5min. In a single metal catalyst added a second component Mo can effectively improve the catalytic activity. Fe-Mo double metal catalysts internal sampling got the better carbon nanotubes yield and morphology, explained for this catalyst, high temperature was suitable for synthetic carbon nanotubes. Best experimental conditions for:catalyst calcining temperature600℃, the synthesis temperature900℃,sampling time10min. Through the sampling method improvement:no carbon source of catalysts in the preheated, experimental results also had a good directional carbon nanotubes array. In the different catalysts, carbon nanotubes best growth condition is different, this also showed the catalyst is the core of the synthesis of carbon nanotubes.