Thermal annealing synthesis of titanium-dioxide nanowire-nanoparticle hetero-structures

Journal Article · Fri Oct 15 00:00:00 EDT 2010 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2010.08.022· OSTI ID:21432454

Yu, Choongho ^[1]; Park, Jongbok ^[1]

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1. Department of Mechanical Engineering, Texas A and M University, College Station, TX 77843 (United States)

Crystalline TiO{sub 2} nanowire-nanoparticle hetero-structures were successfully synthesized from titanium foils by using a simple thermal annealing method with the aid of CuCl{sub 2} at the atmospheric pressure. Nanowires were grown from Ti foils by simply annealing Ti foils at 850 {sup o}C. Then, TiCl{sub 4} was delivered to TiO{sub 2} nanowires so as to precipitate TiO{sub 2} nanoparticles on nanowire surfaces. At 750 {sup o}C reaction temperature, nanoparticles of tens of nanometers in diameter were well distributed on pre-grown nanowire forests. Nanoparticles were likely to be precipitated by TiCl{sub 4} decomposition or oxidation and that require high temperatures above {approx}650 {sup o}C. Electron microscopy, X-ray diffraction, and UV-vis spectroscopy analyses show they have the rutile polycrystalline structure with a slightly enlarged bandgap compared to that of bulk TiO{sub 2}. The influence of key synthesis parameters including reaction temperature, reaction time, and quantity of supplied materials on the incorporating nanoparticles was also systematically studied. The optimum reaction condition in the present paper was identified to be 750 {sup o}C annealing with repetitive 20 min reactions. A higher reaction temperature yielded larger diameter particles, and higher loading of Ti produced dense particles without changing the particle size. Finally, this method could be utilized for synthesizing other metal oxide nanowires-nanoparticle hetero-structures. - Graphical abstract: Schematic of proposed reaction mechanisms for synthesizing the hetero-structures: (a) TiO{sub 2} nanowires were grown as base structures for capturing TiCl{sub 4} gas. (b) TiCl{sub 4} gas was oxidized, precipitating crystalline TiO{sub 2} nanoparticles. (c) Repeated particle-incorporation process created tree-like hetero-structures.

• OSTI ID: 21432454
• Journal Information: Journal of Solid State Chemistry, Vol. 183, Issue 10; Other Information: DOI: 10.1016/j.jssc.2010.08.022; PII: S0022-4596(10)00356-7; Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
77 NANOSCIENCE AND NANOTECHNOLOGY
ANNEALING
COPPER CHLORIDES
ELECTRON MICROSCOPY
FOILS
QUANTUM WIRES
RUTILE
SOLAR CELLS
SYNTHESIS
TEMPERATURE RANGE 0400-1000 K
TITANIUM CHLORIDES
TITANIUM OXIDES
X-RAY DIFFRACTION
CHALCOGENIDES
CHLORIDES
CHLORINE COMPOUNDS
COHERENT SCATTERING
COPPER COMPOUNDS
COPPER HALIDES
DIFFRACTION
DIRECT ENERGY CONVERTERS
EQUIPMENT
HALIDES
HALOGEN COMPOUNDS
HEAT TREATMENTS
MATERIALS
MICROSCOPY
MINERALS
NANOSTRUCTURES
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
RADIOACTIVE MATERIALS
RADIOACTIVE MINERALS
SCATTERING
SOLAR EQUIPMENT
TEMPERATURE RANGE
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS