Emerging Fields in Sol-Gel Science and Technology pp 195-202 | Cite as
Anatase-Rutile Phase Transformation of Cu2+ Doped TiO2 in a Non-Reducing Atmosphere
Abstract
The anatase-rutile phase transformation of TiO2 containing various Cu2+ amounts of Cu ions was investigated in argon atmosphere by means of X ray diffraction and electron spin resonance spectroscopy. The samples were prepared by the sol-gel method from titanium(IV) isopropoxide and copper(II) nitrate. The amorphous samples were calcined in argon atmosphere for 2 h at different temperatures. In the presence of Cu2+, the anatase-rutile transition temperature is lower than the corresponding one in pure TiO2. The transformation in argon atmosphere changes the transition temperatures due to the spontaneous reduction of Cu2+ and Ti4+ ions to metallic copper and Ti3+ respectively. The broadening of the electron spin resonance spectra from this ion show that Ti3+ ions are present in different sites into the TiO2 lattice. This are confirmed by electron spin resonance and allowed us to follow the phase transformation in detail.
Keywords
Electron Spin Resonance Argon Atmosphere Electron Spin Resonance Spectrum Phase Transition Temperature Metallic CopperPreview
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References
- 1.P. Cacciafesta, K. R. Hallam, C. A. Oyedepo, A. D. L. Humphris, M. J. Miles and K. D. Jandt. Characterization of ultraflat titanium oxide surfaces, Chem. Mater. 14 (2002) 777.CrossRefGoogle Scholar
- 2.J A. Navío, G. Colón M. Macías, C. Real and M. I. Litter. Iron-doped titania semiconductor powders prepared by a sol-gel method. Part I: synthesis and characterization, Appl. Catal. A 177 (1999) 111.CrossRefGoogle Scholar
- 3.F. C. Gennari and D. M. Pasquevich. Enhancing effect of iron chlorides on the anataserutile transition in titanium dioxide, J. Am. Ceram. Soc. 82 (7) (1999) 1915.CrossRefGoogle Scholar
- 4.X. Ding and X. Liu. Correlation between anatase-to-rutile transformation and grain growth in nanocrystalline titania powders, J. Mater. Res. 13 (9) (1998) 2556.CrossRefGoogle Scholar
- 5.N. I. Al-Salim, S. A. Bagshaw, A. Bittar, T. Kemmitt, A. J. McQuillan, A. M. Mills, and M. J. Ryan. Characterization and activity of sol-gel-prepared TiO2 photocatalysts modified with Ca, Sr, or Ba ion additives, J. Mater. Chem. 10 (2000) 2358.CrossRefGoogle Scholar
- 6.F. C. Gennari and D. M. Pasquevich. Kinetics of the anatase-rutile transformation in TiO2 in the presence of Fe2O3, J. Mater. Sci. 33 (1998) 1571.CrossRefGoogle Scholar
- 7.G. Cordoba, R. Arroyo, J. L. G. Fierro, M. Viniegra. Study of xerogel-glass transition of CuO/SiO2, J. Solid State Chem. 123 (1996) 93.CrossRefGoogle Scholar
- 8.M. Shareefuddin, M. Jamal, M. N. Chary. Electron spin resonance and optical absorption spectra of Cu2+ ions in xNaI-(30-x)Na2O-70B2O3 glasses, J. Non-Cryst. Solids 201 (1996) 95.CrossRefGoogle Scholar
- X. Li, A. Vannie. ESR studies of well-dispersed Ag crystallites on SiO2, J. Catal. 151 (1995)87.CrossRefGoogle Scholar
- 10.G. Cordoba, M. Viniegra, J. L. G. Fierro, J. Padilla and R. Arroyo. TPR, ESR, and XPS study of Cu2+ ions in sol-gel derived TiO2, J. Solid State Chem. 138 (1998) 1.CrossRefGoogle Scholar
- 11.L. Bonneviot, G. L. Halller. EPR characterization of Ti3+ ions at the metal-support interface in Pt/TiO2 catalysts, J. Catal. 113 (1988) 96.CrossRefGoogle Scholar
- 12.M. Del Arco, A. Caballero, P. Malet, V. Rives. Effect of consecutive and alternative oxidation and reduction treatments on the interactions between titania (anatase and rutile) and copper, J. Catal. 113 (1988) 120.CrossRefGoogle Scholar