Sonochemical synthesis of metal oxides and phosphates
| Authors | |
|---|---|
| Year of publication | 2005 |
| Type | Article in Proceedings |
| Conference | Pacifichem 2005 - ENVR 531 |
| MU Faculty or unit | |
| Citation | |
| Field | Inorganic chemistry |
| Keywords | iron oxide; sonochemical synthesis |
| Description | Sonochemical processes are due to their nonequilibrium nature employed for the preparation of amorphous and nanoscopic materials. Physical and chemical properties of the reaction solvent influence the nature of the obtained products. We found that ultrasound-activated reactions of metalloorganic precursors in inert (tetraglyme) and reactive (tributyl phosphate) solvents provide oxide and phosphate materials, respectively. Aluminum triisopropoxide and aluminum tris(acetylacetonate) were used to prepare both aluminum oxide and phosphate depending on the employed solvent. Similarly, sonicated solutions of iron tris(acetylacetonate) in tributyl phosphate provide iron phosphate while colloidal solutions of amorphous nanoscopic particles of iron oxide are formed in tetraglyme. The sonochemically produced powders were characterized by a variety of physico-chemical methods. IR spectroscopy, elemental analysis and thermal analysis established the presence of surface organic groups in the as-prepared samples and their removal by heating in air. SEM showed nearly spherical uniform nanoparticles of Fe2O3 with an average diameter of 20 nm. The specific surface area of nanopowders was established from nitrogen adsorption isotherms by the BET method. Amorphous nature of the as-prepared iron oxide was exhibited in the HRTEM micrographs. The crystallization process was followed by the variable temperature powder XRD. The specific surface area increased upon calcination to 300 şC. |
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