Controlled Fabrication of Core鈥揝hell TiO2/C and TiC/C Nanofibers on Ti Foils and Their Field-Emission Properties

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• 作者：Xuming Zhang ; Kaifu Huo ; Hairong Wang ; Biao Gao ; Jijiang Fu ; Tak-Fu Hung ; Paul K Chu
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2012
• 出版时间：February 22, 2012
• 年：2012
• 卷：4
• 期：2
• 页码：1037-1042
• 全文大小：443K
• 年卷期：v.4,no.2(February 22, 2012)
• ISSN：1944-8252

文摘

Core鈥搒hell TiO₂/C and TiC/C nanofibers are fabricated in situ on Ti and Al ion-implanted Ti substrates by a thermochemical reaction in acetone and the growth mechanism is described. Implantation of Al into Ti leads to in situ growth of TiC/C in lieu of TiO₂/C nanofibers. This is because Al has a higher affinity to oxygen than Ti and Ti reacts preferentially with C to form TiC. The Ti foil serves as both the Ti source and substrate for the core鈥搒hell TiO₂/C and TiC/C NFs to ensure strong bonding and small contact resistance between the Ti substrate and the core鈥搒hell field emitters. The core鈥搒hell TiC/C and TiO₂/C nanofibers have similar morphology and structure, but the TiC/C nanofibers possess better field emission properties with a turn on field (E_to) of 2.2 V/渭m compared to an E_to of 3.2 V/渭m measured from the TiO₂/C nanofibers. The enhanced field-emission property of the TiC/C nanofibers is attributed to the high electrical and thermal conductivity of the TiC inner core, which provides a more effective electron transfer pathway between the cathode and C shell emitters.

Keywords:

TiO₂/C and TiC/C core鈭抯hell nanostructures; fabrication; electron field emission