Facile Hydrothermal Synthesis of Fe3O4/C Core–Shell Nanorings for Efficient Low-Frequency Microwave Absorption
| Autor: | Yana Li, Yun Liu, Guoxiu Tong, Tingting Cui, Yanting Zhao, Tong Wu, Xiang Zeng |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Ostwald ripening
Permittivity Materials science Reflection loss Analytical chemistry 02 engineering and technology Coercivity 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Hydrothermal circulation 0104 chemical sciences symbols.namesake symbols Hydrothermal synthesis General Materials Science 0210 nano-technology Absorption (electromagnetic radiation) Microwave |
| Zdroj: | ACS Applied Materials & Interfaces. 8:7370-7380 |
| ISSN: | 1944-8252 1944-8244 |
| Popis: | Using elliptical iron glycolate nanosheets as precursors, elliptical Fe3O4/C core-shell nanorings (NRs) [25 ± 10 nm in wall thickness, 150 ± 40 nm in length, and 1.6 ± 0.3 in long/short axis ratio] are synthesized via a one-pot hydrothermal route. The surface-poly(vinylpyrrolidone) (PVP)-protected-glucose reduction/carbonization/Ostwald ripening mechanism is responsible for Fe3O4/C NR formation. Increasing the glucose/precursor molar ratio can enhance carbon contents, causing a linear decrease in saturation magnetization (Ms) and coercivity (Hc). The Fe3O4/C NRs reveal enhanced low-frequency microwave absorption because of improvements to their permittivity and impedance matching. A maximum RL value of -55.68 dB at 3.44 GHz is achieved by Fe3O4/C NRs with 11.95 wt % C content at a volume fraction of 17 vol %. Reflection loss (RL) values (≤-20 dB) are observed at 2.11-10.99 and 16.5-17.26 GHz. Our research provides insights into the microwave absorption mechanism of elliptical Fe3O4/C core-shell NRs. Findings indicate that ring-like and core-shell nanostructures are promising structures for devising new and effective microwave absorbers. |
| Databáze: | OpenAIRE |
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