Preparation And Electrochemical Properties Of The CNT/TiO₂Composite Film

CNT/TiO₂composite film attracts researcher’s attention nowadays due to itsbroad potential applications in the filed of energy. In this thesis, we prepared auniform and continuous self-support CNT/TiO₂composite film by one-step chemicalvapor deposition method and studied its structure and electrochemical properties.CNT/TiO₂fiber was prepared by densing the CNT/TiO₂film with water, and itsadsorption and mechanical properties were discussed.The CNT/TiO₂composite film can be continuously spun out and the yield wasapproximately120mg/h. Its microstructure was a uniform network: FWCNT bundlesinterconnected a network frame, bamboo-like CNT and TiO₂parricles mixed witheach other and distributed on the network. The diameter of FWCNT bundles is about20nm and the bamboo-like CNT is about30-40nm, while the diameter of TiO₂isabout40nm. TiO₂consists of86.5wt.%rutile and13.5wt.%anatase. Theelectrochemical performance of the film can be directly tested after simple cutting.The first discharge capacity was as high as1037mAh/g, and at the current density of30mA/g and300mA/g, the capacity is470mAh/g and250mAh/g respectively. Wecan easily change the TiO₂content in the composite film by adjusting the weight ofTTIP in the raw material. The network structure of the film can not be changed withthe change of the TiO₂content. The surface area, pore volume and lithium-ionperformance increased with the increasing of TiO₂content. The Fe in the film can beremoved after acid treatment, but the structure of the CNT is also damaged so that thelithium-ion performance is reduced. The amorphous carbon can be effectivelyremoved by heat treatment and the capacitor performance as well as the lithium-ionperformance increased at the small current density.We prepared CNT/TiO₂composite fiber by densing CNT/TiO₂composite filmwith water and its adsorption of methyl orange is up to90mg/g. The strength of fiberprepared with methanol increased by119%.