Synthesis and Crystal Growth Mechanism of Titanium Dioxide Nanorods

doi:10.3724/SP.J.1077.2012.00045

Abstract

Abstract:

Highly crystalline and monodisperse anatase TiO₂ nanorods were synthesized successfully via an improved solvothermal method. The shape evolution of TiO₂ nanorod was investigated by adjusting the reaction parameters, such as reaction duration and temperature. The phase structures, morphologies, and sizes of as-prepared TiO₂ nanoparticles were investigated in detail by XRD, TEM, and HRTEM. The photocatalytic properties of the product were measured by decomposition of methylene blue under full spectrum light irradiation. When Ostwald Ripening is dominant, the TiO₂ nanorods grow along the <001> crystallographic direction. When Ostwald Ripening is depressed at lower temperature, Oriented Attachment occurs. And primary nanoparticles join together by sharing a common (001) facet. The driving force of shape evolution and crystal growth of TiO₂ nanocrystals is reducing the high surface free energy. Compared with P25, the as-prepared TiO₂ nanorods exhibit a superior photocatalytic activity, which is attributed to the high crystallinity.

Key words: TiO₂ nanorod, crystal growth, photocatalyst, Ostwald ripening, oriented attachment

CLC Number:

O482

CHEN Chao, WANG Zhi-Yu. Synthesis and Crystal Growth Mechanism of Titanium Dioxide Nanorods[J]. Journal of Inorganic Materials, 2012, 27(1): 45-48.

Figures/Tables 5

Fig. 1 TEM and HRTEM images of TiO2 nanoparticles prepared via Ostwald ripening for different time

Fig. 2 XRD pattern of TiO2 nanorod grown by Ostwald Ripening at 280℃ for 24 h

Fig. 3 (a) TEM and (b) HRTEM images of TiO2 dumbbell- like nanorods grown by Oriented Attachment

Fig. 4 Formation schematic illustration of TiO2 nanorods via Ostwald Ripening (OR) and Oriented Attachment (OA)

Fig. 5 Catalytic properties of TiO2 nanorods and P25

References 17

[1]	O'Regan B, Gratzel M. A low-cost, high-efficiency solar cell based on dye-sensitized colloidal TiO2 films. Nature, 1991, 353(24): 737-739.
[2]	Chen X B, Mao S S. Titanium dioxide nanomaterials: synthesis, properties, modifications, and applications. Chem. Rev., 2007, 107(7): 2891-2959.
[3]	Li Y M, Somorjai G A. Nanoscale advances in catalysis and energy applicatiions. Nano Lett., 2010, 10(7): 2289-2295.
[4]	Fujishima A, Honda K. Electrochemical photolysis of water at a semiconductor electrode. Nature, 1972, 238(5358): 37-38.
[5]	LIU Bo, KONG Wei, YE Bo, et al. Effect of heating rate on the morphology of nano titanium dioxide. Journal of Inorganic Materials, 2010, 25(9): 906-910.
[6]	Yu J C, Yu, J, Ho W K, et al. Preparation of highly photocatalytic active nano-sized TiO2 particles via ultrasonic irradiation. Chem. Commun., 2001: 1942-1943.
[7]	Talapin D V, Rogach A L, Shevchenko E V, et al. Dynamic distribution of growth rates within the ensembles of colloidal Ⅱ-Ⅵ and Ⅲ-Ⅴ semiconductor nanocrystals as a factor governing their photoluminescence efficiency. J. Am. Chem. Soc., 2002, 124(20): 5782-5790.
[8]	Liu M, Piao L Y, Zhao L, et al. Anatase TiO2 single crystals with exposed {001} and {110} facets: facile synthesis and enhanced photocatalysis. Chem. Commun., 2010, 46(10): 1664-1666.
[9]	Yu J G, Fan J J, Lv K. Anatase TiO2 nanosheets with exposed (001) facets: improved photoelectric conversion efficiency in dye-sensitized solar cells. Nanoscale, 2010, 2(10): 2144-2149.
[10]	Dinh C T, Nguyen T D, Kleitz F, et al. Shape-controlled synthesis of highly crystalline titania nanocrystals. ACS Nano, 2009, 3(11): 3737-3743.
[11]	Seyed-Razavi A, Snook I K, Barnard A S. Origin of nanomorpholoty: does a complete theory of nanoparticle evolutiion exist?J. Mater. Chem., 2010, 20(3): 416-421.
[12]	Kang L T, Fu H B, Cao X Q, et al. Controlled morphogenesis of organic polyhedral nanocrystals from cubes, cubooctahedrons, to octahedrons by manipulating the growth kinetics. J. Am. Chem. Soc., 2011, 133(6): 1895-1901.
[13]	Oskam G, Hu Z, Penn R L, et al. Coarsening of metal ozide nanoparticles. Phys. Rev. E, 2002, 66(1): 011403-1-4.
[14]	Diebold U. The surface science of titanium dioxide. Surf. Sci. Rep., 2002, 48(5-8): 53-229.
[15]	Alimohammadi M, Fichthorn K A. Molecular dynamics simulation of the aggregation of titanium dioxide nanocrystals: preferential alignment. Nano Lett., 2009, 9(12): 4198-4203.
[16]	Dai Y, Cobley C M, Zeng J, et al. Synthesis of anatase TiO2 nanocrystals with exposed {001} facets. Nano Lett., 2009, 9(6): 2455-2459.
[17]	Li J, Yu Y, Chen Q, et al. Controllable synthesis of TiO2 single crystals with tunable shapes using ammonium-exchanged titanate nanowires as precursors. Cryst. Growth Des., 2010, 10(5): 2111-2115.