Large-scale synthesis of hollow titania spheres via flame combustion--颗粒学报PARTICUOLOGY

Liu, J., Hu, Y., Gu, F., & Li, C. (2011). Large-scale synthesis of hollow titania spheres via flame combustion. Particuology, 9(6), 632–636. https://doi.org/10.1016/j.partic.2010.12.004

Large-scale synthesis of hollow titania spheres via flame combustion

Jie Liu, Yanjie Hu, Feng Gu, Chunzhong Li^*

Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science & Technology, Shanghai 200237, China

10.1016/j.partic.2010.12.004

Volume 9, Issue 6, December 2011, Pages 632-636

Received 13 October 2010, Revised 5 December 2010, Accepted 13 December 2010, Available online 1 September 2011.

E-mail: czli@ecust.edu.cn; huyanjie@ecust.edu.cn

Highlights

Abstract

A one-step method for continuous large-scale synthesis of well-defined hollow titania spheres was established by feeding titanium tetrachloride mixed with ethanol vapor to a facile diffusion flame. A mixture of TiCl₄ and C₂H₅OH vapor was transported at 100 m/s into a flame reactor and condensed into mesoscale droplets due to Joule–Thomson cooling and the entrainment of cool gases into the expanding high-speed jet. Hollow crystalline TiO₂ spheres with good thermal stability were formed after the hydrolysis of TiCl₄ in the H₂/air flame at about 1500 °C. Structural characterization indicates that the hollow spheres, with uniform diameter of 300 nm and shell thickness of 35 nm, consist of 20–30 nm TiO₂ nanocrystallites. A formation mechanism of the hollow spheres was proposed, involving the competition between chemical reaction and diffusion during the flame process. The present study provides a new pathway for continuous and large-scale engineering of hollow nanomaterials.

Graphical abstract

Keywords

Flame combustion; Hollow spheres; Titania; Formation mechanism; Large-scale

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