Anatase-TiO2 Nanomaterials: Analysis of Key Parameters Controlling Crystallization

Journal Article · Mon Jan 01 04:00:00 EST 2007 · Journal of the American Chemical Society

DOI:https://doi.org/10.1021/ja074064m· OSTI ID:959769

Fernandez-Garcia, M; Belver, C; Hanson, J; Wang, X; Rodriguez, J

Nanoparticulated TiO2 materials with anatase structure were synthesized by using a microemulsion method. The structural characteristics of the amorphous solid precursors and their evolution during thermal treatments were studied by using X-ray absorption structure (X-ray absorption near edge structure XANES and extended X-ray absorption fine structure EXAFS), XRD-PDF (X-ray diffraction-pair distribution function), and infrared spectroscopy. Concerning the precursor materials, XANES and EXAFS showed a local order closely related to that of the anatase structure but containing defective, undercoordinated Ti5c4+ species in addition to normal Ti6c4+ species. The PDF technique detects differences among samples in the local order (below 1 nm) and showed that primary particle size varies throughout the amorphous precursor series. The physical interpretation of results concerning the amorphous materials and their evolution under thermal treatment gives conclusive evidence that local, intraparticle ordering variations determine the temperature for the onset of the nucleation process and drive the solid behavior through the whole crystallization process. The significance of this result in the context of current crystallization theories of oxide-based nanocrystalline solids is discussed.

• Research Organization: Brookhaven National Laboratory (BNL) National Synchrotron Light Source
• Sponsoring Organization: Doe - Office Of Science
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 959769
• Report Number(s): BNL--82755-2009-JA
• Journal Information: Journal of the American Chemical Society, Journal Name: Journal of the American Chemical Society Vol. 129; ISSN JACSAT; ISSN 0002-7863
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
77 NANOSCIENCE AND NANOTECHNOLOGY
ABSORPTION
CRYSTALLIZATION
DISTRIBUTION
FINE STRUCTURE
MATERIALS
MICROEMULSIONS
NUCLEATION
PARTICLE SIZE
PRECURSOR
SPECTROSCOPY
national synchrotron light source