TY - JOUR
T1 - Enhanced microwave absorption properties of graphite nanoflakes by coating hexagonal boron nitride nanocrystals
AU - Zhong, Bo
AU - Liu, Wei
AU - Yu, Yuanlie
AU - Xia, Long
AU - Zhang, Jiulin
AU - Chai, Zhenfei
AU - Wen, Guangwu
N1 - KAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This work was supported by the National Natural Science Foundation of China (51102060, 51172050, 51302049, 51372052 and 51672059), the Postdoctoral Science Foundation of China (2013M531036), and Shandong Province Young and Middle-Aged Scientists Research Awards Fund (BS2013CL003).
PY - 2017/5/31
Y1 - 2017/5/31
N2 - We report herein the synthesis of a novel hexagonal boron nitride nanocrystal/graphite nanoflake (h-BNNC/GNF) composite through a wet-chemistry coating of graphite nanoflakes and subsequent in-situ thermal treatment process. The characterization results of X-ray diffraction, scanning electron microscope, transmission electron microscope, energy dispersive X-ray spectrum, and X-ray photoelectron spectroscopy demonstrate that h-BNNCs with diameter of tens of nanometers are highly crystallized and anchored on the surfaces of graphite nanoflakes without obvious aggregation. The minimum reflection loss (RL) value of the h-BNNC/GNF based absorbers could reach −32.38dB (>99.99% attenuation) with the absorber thickness of 2.0mm. This result is superior to the other graphite based and some dielectric loss microwave absorption materials recently reported. Moreover, the frequency range where the RL is less than −10dB is 3.49-17.28GHz with the corresponding thickness of 5.0 to 1.5mm. This reveals a better electromagnetic microwave absorption performance of h-BNNC/GNFs from the X-band to the Ku-band. The remarkable enhancement of the electromagnetic microwave absorption properties of h-BNNC/GNFs can be assigned to the increase of multiple scattering, interface polarization as well as the improvement of the electromagnetic impedance matching of graphite nanoflakes after being coated with h-BNNCs.
AB - We report herein the synthesis of a novel hexagonal boron nitride nanocrystal/graphite nanoflake (h-BNNC/GNF) composite through a wet-chemistry coating of graphite nanoflakes and subsequent in-situ thermal treatment process. The characterization results of X-ray diffraction, scanning electron microscope, transmission electron microscope, energy dispersive X-ray spectrum, and X-ray photoelectron spectroscopy demonstrate that h-BNNCs with diameter of tens of nanometers are highly crystallized and anchored on the surfaces of graphite nanoflakes without obvious aggregation. The minimum reflection loss (RL) value of the h-BNNC/GNF based absorbers could reach −32.38dB (>99.99% attenuation) with the absorber thickness of 2.0mm. This result is superior to the other graphite based and some dielectric loss microwave absorption materials recently reported. Moreover, the frequency range where the RL is less than −10dB is 3.49-17.28GHz with the corresponding thickness of 5.0 to 1.5mm. This reveals a better electromagnetic microwave absorption performance of h-BNNC/GNFs from the X-band to the Ku-band. The remarkable enhancement of the electromagnetic microwave absorption properties of h-BNNC/GNFs can be assigned to the increase of multiple scattering, interface polarization as well as the improvement of the electromagnetic impedance matching of graphite nanoflakes after being coated with h-BNNCs.
UR - http://hdl.handle.net/10754/623762
UR - http://www.sciencedirect.com/science/article/pii/S0169433217316094
UR - http://www.scopus.com/inward/record.url?scp=85019992765&partnerID=8YFLogxK
U2 - 10.1016/j.apsusc.2017.05.232
DO - 10.1016/j.apsusc.2017.05.232
M3 - Article
SN - 0169-4332
VL - 420
SP - 858
EP - 867
JO - Applied Surface Science
JF - Applied Surface Science
ER -