Structural and Morphological Features of Disperse Alumina Synthesized Using Aluminum Nitrate Nonahydrate
| Autor: | Volodymyr M. Sachko, Ivan F. Myronyuk, Volodymyr M. Gun’ko, V. I. Mandzyuk |
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| Jazyk: | angličtina |
| Předmět: |
Boehmite
Materials science Alumina Inorganic chemistry 02 engineering and technology Crystal structure 010402 general chemistry 01 natural sciences law.invention chemistry.chemical_compound Materials Science(all) law Aluminum nitrate nonahydrate General Materials Science Calcination High-resolution transmission electron microscopy Nano Express Nanoparticle morphology 74.62.Bf 021001 nanoscience & nanotechnology Condensed Matter Physics 0104 chemical sciences Amorphous solid Thermogravimetry Chemical engineering chemistry Aggregate texture Hydroxide Aluminum hydroxide 0210 nano-technology Mesoporous material 64.70.K 61.66.Fn |
| Zdroj: | Nanoscale Research Letters |
| ISSN: | 1931-7573 |
| DOI: | 10.1186/s11671-016-1366-0 |
| Popis: | Transformation of Al(NO3)3∙9H2O (upon heating in the range of 20–1200 °C) into blends of amorphous and crystalline boehmite (210–525 °C), amorphous alumina and crystalline γ-Al2O3 (850 °C), and crystalline α-Al2O3 (1100 °C) was analyzed using X-ray diffraction (XRD), high-resolution transmission electron microscope (HRTEM), infrared (IR) spectroscopy, thermogravimetry, and low-temperature nitrogen adsorption. Boehmite consists of nanoparticles of 6–10 nm in diameter, and part of them has crystalline structure observed in HRTEM images, despite they are XRD amorphous. The nanoglobules are surrounded by amorphous aluminum hydroxide with chains of –AlO(H)–O–AlO(H)– of 1–5 nm in length. Heating of samples at 350–525 °C gives mesoporous aluminum hydroxide with a relatively narrow pore size distribution. An increase in calcination temperature to 850 °C decreases the porosity of alumina composed of amorphous and crystalline (γ-Al2O3) phases. Calcination at 1100 °C gives α-Al2O3 with strongly decreased porosity of aggregates. Electronic supplementary material The online version of this article (doi:10.1186/s11671-016-1366-0) contains supplementary material, which is available to authorized users. |
| Databáze: | OpenAIRE |
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