A hierarchical Co @ mesoporous C/ macroporous C sheet composite derived from bimetallic MOF and oroxylum indicum for enhanced microwave absorption

Carbon ◽  
2021 ◽  
Author(s):  
Xiang Zhang ◽  
Jie Cheng ◽  
Zhen Xiang ◽  
Lei Cai ◽  
Wei Lu
2016 ◽  
Vol 12 (2) ◽  
pp. 4204-4212 ◽  
Author(s):  
Maheshwar Sharon ◽  
Ritesh Vishwakarma ◽  
Abhijeet Rajendra Phatak ◽  
Golap Kalita ◽  
Nallin Sharma ◽  
...  

Corn cob, an agricultural waste, is paralyzed at different temperatures (700oC, 800oC and 900oC). Microwave absorption of carbon in the frequency range of 2 GHz to 8 GHz is reported. Carbon activated  with 5%  nickel nitrate showed more than 90% absorption of microwave in the frequency range from 6 GHz to 8 GHz, while carbon activated  with 10% Nickel nitrate treated corn cob showed 90% absorption  in the frequency range of 2.5 GHz to 5 GHz. Carbon showing the best absorption are characterized by XRD, Raman spectra and SEM . It is suggested that corn cob treatment   alone with KOH did not improve the microwave absorption, whereas treatment along with nickel nitrate improved the absorption property much better. It is proposed that treatment with nickel nitrate helps in creating suitable pores in carbon   which improved the absorption behavior because while treating carbon with 1N HCl helps to leach out nickel creating equivalent amount of pores in the carbon.


2009 ◽  
Vol 25 (1) ◽  
pp. 73-76 ◽  
Author(s):  
Hong JIANG ◽  
Jia GUO ◽  
Lu ZHAO ◽  
Hong ZHU

2009 ◽  
Vol 24 (2) ◽  
pp. 340-344 ◽  
Author(s):  
Deng-Ke WANG ◽  
Hao HUANG ◽  
Kuai YU ◽  
Xue-Feng ZHANG ◽  
Xing-Long DONG
Keyword(s):  

2019 ◽  
Vol 55(6) ◽  
pp. 29
Author(s):  
Đái Thị Xuân Trang ◽  
Nguyễn Trọng Tuân ◽  
Trần Thanh Mến ◽  
Lê Thanh Phương Thảo ◽  
Trần Chí Linh ◽  
...  
Keyword(s):  

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2921 ◽  
Author(s):  
Wei Huang ◽  
Yujiang Wang ◽  
Shicheng Wei ◽  
Bo Wang ◽  
Yi Liang ◽  
...  

Hollow magnetic structures have great potential to be used in the microwave absorbing field. Herein, Fe3O4 hollow spheres with different levels of hollowness were synthesized by the hydrothermal method under Ostwald ripening effect. In addition to their microstructures, the microwave absorption properties of such spheres were investigated. The results show that the grain size and hollowness of Fe3O4 hollow spheres both increase as the reaction time increases. With increasing hollowness, the attenuation ability of electromagnetic wave of Fe3O4 spheres increases first and then decreases, finally increases sharply after the spheres break down. Samples with strong attenuation ability can achieve good impedance matching, which it does preferentially as the absorber thickness increases. Fe3O4 hollow spheres show the best microwave absorption performance when the reaction time is 24 h. The minimum reflection loss (RL (min)) can reach −40 dB, while the thickness is only 3.2 mm.


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