Preparation of TiO2@SiO2 coaxial double-walled submicrotubes by trifluidic coaxial electrospinning and its photocatalytic property

Abstract

Coaxial double-walled submicrotubes have potential extensive applications in many fields owing to their peculiar submicrostructures. The electrospinning has become a major method for preparation of one-dimensional nano-or micromaterials. In order to invent a facile technique to fabricate coaxial double-walled submicrotubes, a modified electrospinning was employed. TiO2@SiO2 coaxial double-walled submicrotubes were successfully synthesized by trifluidic coaxial electrospinning technique using tetrabutyl titanate, tetraethyl orthosilicate, polyvinyl pyrrolidone, absolute ethanol, sesame oil, span-80 and chloroform as starting materials. The samples were characterized by thermogravimetry and differential thermal analysis, X-ray diffractometry, Fourier transform infrared spectrometry, scanning electron microscopy, transmission electron microscopy and energy dispersive spectrometry. The results indicated that the products are TiO2@SiO2 coaxial double-walled submicrotubes with an amorphous SiO2 outer shell, a crystalline rutile-typed TiO2 inwall. The submicrotubes possess an average diameter of ca. 680 nm, wall thickness of the tubes of ca. 70 nm, inwall of ca. 40 nm and outer shell of ca. 30 nm. The length of submicrotubes is greater than 20 μm. The formation mechanism of TiO2@SiO2 coaxial double-walled submicrotubes is preliminarily investigated. TiO2@SiO2 coaxial double-walled submicrotubes present better photocatalytic activity on rhodamine B. The simple preparation method is also appropriate for fabricating other coaxial multi-walled nano-or submicrotubes of inorganics. © 2012 Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences.