3D Fe 3 O 4 nanocrystals decorating carbon nanotubes to tune electromagnetic properties and enhance microwave absorption capacity

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2015, Vol.3 (24), p.12621-12625
• Main Authors: Chen, Yi-Hua, Huang, Zi-Han, Lu, Ming-Ming, Cao, Wen-Qiang, Yuan, Jie, Zhang, De-Qing, Cao, Mao-Sheng
• Format: Article
• Language: English
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/C5TA02782A

We fabricated a novel dielectric–magnetic nanostructure by hybridizing 3D Fe 3 O 4 nanocrystals and multi-walled carbon nanotubes through a simple co-precipitation route. The 3D Fe 3 O 4 -MWCNTs composites demonstrate enhanced microwave absorption with tunable strong-absorption wavebands in the frequency range of 2–18 GHz. Double-band microwave absorption appears in the investigated frequency range and at various thicknesses. This depends on the loading concentration of 3D Fe 3 O 4 -MWCNTs. Minimum reflection loss values at 20 wt% loading of −23.0 dB and −52.8 dB are observed at 4.1 GHz and 12.8 GHz, respectively, which are superior to those of pure MWCNTs as well as other hybrids of Fe 3 O 4 . The improved absorption capacity arises from the synergy of dielectric loss and magnetic loss, as well as the enhancement of multiple interfaces among 3D Fe 3 O 4 nanocrystals. All of these factors increase the flexibility of tuning microwave absorption. These results provide a new strategy to tune electromagnetic properties and enhance the capacity of high-efficient microwave absorbers.