Copyright 2009 American Chemical Society
MARCH 3, 2009 VOLUME 25, NUMBER 5
Letters Ultrathin Polycrystalline Hematite and Goethite-Hematite Core-Shell Nanorods S. Cavaliere-Jaricot, A. Brioude,* and P. Miele Laboratoire des Multimate´riaux et Interfaces, UMR 5615, CNRS-UniVersite´ Lyon 1, UniVersite´ de Lyon, 43 bd du 11 NoVembre 1918, F-69622 Villeurbanne, France ReceiVed September 29, 2008. ReVised Manuscript ReceiVed December 4, 2008 We have developed a facile synthesis route to 1D structures of ultrathin polycrystalline hematite and goethite-hematite core-shells. One-dimensional structures of pure hematite and the goethite-hematite core-shell with very small diameters were synthesized in aqueous solution at low temperature with a simple, rapid method based on the oxidation of Fe3O4 nanoparticles without using surfactants.
Hematite (R-Fe2O3), which is the most stable iron oxide under ambient conditions, is environmentally friendly, low cost, very resistant to corrosion, and versatile with n-type semiconducting and magnetic properties. Because of such stability and electronic properties, this oxide has various applications in several fields as a catalyst,1 photocatalyst,2 photoelectrode,3,4 battery electrode,5 gas sensor,6,7 pigment,8 and magnetic material.9 Recently, considerable attention has been directed toward hematite nanostructures of various morphologies because of the novel size- and shape-dependent chemical and physical properties appearing on the nanoscale.10 In particular, 1D nanostructures of R-Fe2O3 such as nanorods (and also nanospindles, nanobelts, * Corresponding author. Phone: +33 4 72 44 84 03. Fax: +33 4 72 44 06 18. E-mail:
[email protected]. 7.
(1) Brown, A. S. C.; Hargreaves, J. S. J.; Rijniersce, B. Catal. Lett. 1998, 53,
(2) Ohmori, T.; Takahashi, H.; Mametsuka, H.; Suzuki, E. Phys. Chem. Chem. Phys. 2000, 2, 3519. (3) Watanabe, A.; Kozuka, H. J. Phys. Chem. B 2003, 107, 12713. (4) Duret, A.; Gratzel, M. J. Phys. Chem. B 2005, 109, 17184. (5) Wu, C.; Yin, P.; Zhu, X.; OuYang, C.; Xie, Y. J. Phys. Chem. B. 2006, 110, 17806. (6) Huo, L.; Li, W.; Lu, L.; Cui, H.; Xi, S.; Wang, J.; Zhao, B.; Shen, Y.; Lu, Z. Chem. Mater. 2000, 12, 790. (7) Han, J. S.; Davey, D. E.; Mulcahy, D. E.; Yu, A. B. Sens. Actuators, B 1999, 61, 83. (8) Feldmann, C. AdV. Funct. Mater. 2003, 13, 101. (9) Zboril, R.; Mashlan, M.; Petridis, D. Chem. Mater. 2002, 14, 969.
nanowires, etc.) are an interesting issue in relation to the magnetic behavior derived from size and shape anisotropies.11,12 A variety of physical and chemical strategies have been developed for the synthesis of size-controlled hematite nanorods. Among them, we can cite pulsed laser deposition (PLD),13 metal-organic chemical vapor deposition (MOCVD),12 hydrothermal synthesis,11,14-17 microwave-assisted hydrothermal synthesis,18 sol-gel processes,19,20 template-assisted synthesis,21 iron-water vapor reaction,14 forced hydrolysis,22,23 and micellar (10) Zysler, R. D.; Fiorani, D.; Testa, A. M.; Suber, L.; Agostinelli, E.; Godinho, M. Phys. ReV. B 2003, 68, 212408. (11) Sorescu, M.; Brand, R. A.; Mihaila-Tarabasanu, D.; Diamandescu, L. J. Alloys Compd. 1998, 280, 273. (12) Wu, J.-J.; Lee, Y.-L.; Chiang, H.-H.; Wong, D. K.-P. J. Phys. Chem. B 2006, 110, 18108. (13) Morber, J. R.; Ding, Y.; Haluska, M. S.; Li, Y.; Liu, J. P.; Wang, Z. L.; Snyder, R. L. J. Phys. Chem. B 2006, 110, 21672. (14) Zhao, Y.; Dunnill, C. W.; Zhu, Y.; Gregory, D. H.; Kockenberger, W.; Li, Y.; Hu, W.; Ahmad, I.; McCartney, D. G. Chem. Mater. 2007, 19, 916. (15) Zhong, Z.; Ho, J.; Theo, J.; Shen, S.; Gedanken, A. Chem. Mater. 2007, 19, 4776. (16) Lian, S.; Wang, E.; Kang, Z.; Bai, Y.; Gao, L.; Jiang, M.; Hu, C.; Xu, L. Solid State Commun. 2004, 129, 485. (17) Jia, B.; Gao, L.; Sun, J. J. Am. Ceram. Soc. 2007, 90, 1315. (18) Zhang, X.; Li, Q. Mater. Lett. 2008, 62, 988. (19) Woo, K.; Lee, H. J. J. Magn. Magn. Mater. 2004, 272-276, e1155. (20) Itoh, H.; Sugimoto, T. J. Colloid Interface Sci. 2003, 265, 283. (21) Zhang, L. Y.; Xue, D. S.; Xu, X. F.; Gui, A. B.; Gao, C. X. J. Phys.: Condens. Matter 2004, 16, 4541.
10.1021/la803172b CCC: $40.75 2009 American Chemical Society Published on Web 01/30/2009
2552 Langmuir, Vol. 25, No. 5, 2009
Letters
Figure 2. High-resolution TEM micrograph of hematite nanorods with a very small diameter of
