Synthesis and microwave absorbing properties of CeO2/multi-walled carbon nanotubes composites

Synchronously boosting microwave-absorbing and heat-conducting capabilities in CeO2/Ce(OH)3 core–shell nanorods/nanofibers via Fe-doping amount control

“…Notably, the EAB max of 9.26 GHz is 1.32-18.52 times larger than those of CeO 2 /Ce(OH) 3 CSNFs (5.12 GHz) and other CeO 2 or CeO 2 -based composites (0.57.04 GHz). [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28]46,47 (ii) Excellent low-frequency absorption. The narrow band for CeO 2 /Ce(OH) 3 CSNFs over 7.0-18.0 GHz (Fig.…”

“…The matching thickness of 1.5-1.7 mm for Fe-doped CeO 2 /Ce(OH) 3 CSNFs is much smaller than those of CeO 2 /Ce(OH) 3 CSNFs (2.4 mm) and other cerium-based composites (2.0-7.8 mm). [14][15][16][17][18][19][20][21][22][23][24][25][26]46,47 According to the equation t m ¼ nc= 4f m ffiffiffiffiffiffiffiffiffiffiffiffiffi m r j j e r j j p À Á , 48 matching thickness varies inversely with frequency, permittivity, and permeability. Therefore, the smaller matching thickness of Fe-doped CeO 2 /Ce(OH) 3 CSNFs is ascribed to the incremental permeability and permittivity (Fig.…”

“…Cerium-based compounds (containing Ce(OH) 3 , Ce 2 O 3 , and CeO 2 ) have promising applications as gas sensors, industrial catalysts, and solid oxide fuel cells due to their abundant defects, 4f electrons, and lanthanide contraction effect. [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] Besides, cerium-based compounds can function as microwave absorbers due to polarization loss induced by oxygen vacancy defects. But they still do not have a wide range of applications since they bear a narrow bandwidth (EABW/d = 0.06-3.85 GHz mm À1 ), a thick thickness (2.0-6.5 mm), and a high filling ratio (450%) owing to the lack of ferromagnetic resonances and/or polarizations.…”

“…But they still do not have a wide range of applications since they bear a narrow bandwidth (EABW/d = 0.06-3.85 GHz mm À1 ), a thick thickness (2.0-6.5 mm), and a high filling ratio (450%) owing to the lack of ferromagnetic resonances and/or polarizations. To improve the EMW absorbing capabilities (EMWACs), several methods such as morphology control, [14][15][16] doping with other atoms (Fe, 17 Zn, 18 Co 19 ), Ce-doped ferrites, [20][21][22] and combining with CNT, 23,24 rGO, 19 PANi, 25 MoS 2 , 26 Co 3 O 4 , 27 and Fe 28 have been adopted. However, the as-obtained EMWACs fail to fulfil the requirements of practical application.…”

Ceria-Spiderweb Nanosheets Unlock the Energy-Storage Properties in the “Sleeping” Triplite (Mn2(PO4)F)

“…The difference in the electrochemical performance between MPF-CeO 2 and MPF-C-CeO 2 is attributed to the synergistic interaction between the conductive species, carbon and CeO 2 , which introduces extra conductivity to the MPF (i.e., reduced impedance, confirmed by the EIS data as discussed later). Carbon and ceria can co-operatively increase the specific discharge capacity of the MPF, which is consistent with the findings of Wang et al, 42 who showed that the incorporation of CeO 2 nanoparticles onto the surface of carbon nanotubes leads to enhanced space charge polarization, interfacial polarization, and conductivity (reduced impedance) due to the supply of oxygen vacancies by the CeO 2 nanoparticles.…”