Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10625541 | Ceramics International | 2014 | 12 Pages |
Abstract
Un-doped and Co-doped sol-gel TiO2 nanopowders have been prepared and structurally characterized. Three Co mass concentrations related to TiO2 content have been used: 0.5, 1 and 2 wt%. The morpho-structural changes due to the thermal treatment and dopant presence were followed by: thermal analysis methods, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and magnetic measurements. A detailed XRD analysis, based on an own calculus program, has established the lattice constants, the average size of the crystallites, , and the average lattice strains, , which can give some information about the structural disorder. The values of the lattice constants lead to the conclusion that a solid solution of the CoxTi1âxO2 form was obtained. The Co concentration imprints the paramagnetic behavior to the solid solutions. It influences the evolution of the and factors by the competition between: the deficit of oxygen acquired by un-doped TiO2 in the sol-gel process (influenced by temperature), the dopant diffusion in the host lattice (influenced by ionic radius and valence) and the super-exchange interactions between the magnetic moments of the molecules of the solid solution (influenced by the concentration of Co). The sample with 1 wt% Co thermally treated at 400 °C ensures the best photocatalytic activity in the advanced degradation of nitrobenzene from water.
Related Topics
Physical Sciences and Engineering
Materials Science
Ceramics and Composites
Authors
Nicolae DrÄgan, Maria CriÅan, MÄlina RÄileanu, Dorel CriÅan, Adelina Ianculescu, PetruÅ£a Oancea, Simona ÅomÄcescu, Ligia Todan, Nicolae StÄnicÄ, Bogdan Vasile,