Porous LaFeO3/Silica Nanocomposites via Sol-Gel Mixing Involving Citric Acid
| Autor: | Abd El-Aziz A. Said, Ahmed A. Elsamahy, Kamal M.S. Khalil, Walaa A. Elhamdy |
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| Rok vydání: | 2016 |
| Předmět: |
Nanocomposite
Materials science Inorganic chemistry Oxide 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences law.invention chemistry.chemical_compound Colloid and Surface Chemistry Adsorption chemistry Chemical engineering law Desorption Mixed oxide Calcination 0210 nano-technology Porosity Sol-gel |
| Zdroj: | Colloids and Surfaces A: Physicochemical and Engineering Aspects. 506:840-848 |
| ISSN: | 0927-7757 |
| DOI: | 10.1016/j.colsurfa.2016.07.068 |
| Popis: | A series of 10, 20 and 30% (w/w) La2O3-Fe2O3/silica composites were synthesized by mixing of La-Fe citrate complex gels with spherical silica sols. This was followed by calcination of the formed xerogel at 550 °C and 750 °C for 3 h. The materials were characterized by XRD, simultaneous thermal analyses (TGA-DTA), FTIR, N2 gas adsorption/desorption isotherms at ⿿196 °C, and TEM techniques. Results indicated complete decomposition of the precursor complex upon calcination and development of porous composites with high surface area. However, processing of the La-Fe citrate complex gel or the silica precursors without mixing led to formation of LaFeO3 perovskite oxide type and silica with very low surface area amounting to 4 and 11 m2/g, respectively. Thus the process led to the formation of nanosized amorphous-like LaFeO3 phase (as a shell) on the surface of the spherical silica particles (core). The enhancement of surface area and porosity of the composites was correlated to the dispersion of La-Fe precursor on the surface of silica sol. The method can be generalized for other mixed oxides. |
| Databáze: | OpenAIRE |
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