NiFe2O4/coal-based carbon composites with magnetic properties and microwave absorption capacity prepared through microwave radiation and hydrothermal reaction

• Published in: Synthetic metals Vol. 297; p. 117404
• Main Authors: Meng, Yongli, Liu, Yin, Yang, Chong, Kong, Ling Bing
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.08.2023
• Subjects: Coal-based carbon; Electromagnetic wave absorption; Magnetic properties; Microwave irradiation; Ni ferrite; Coal-based carbon; Microwave irradiation; Electromagnetic wave absorption; Ni ferrite; Magnetic properties
• ISSN: 0379-6779; 1879-3290
• DOI: 10.1016/j.synthmet.2023.117404

Nickel ferrite/coal-based carbon (NiFe2O4/CBC) composites were synthesized by using microwave irradiation and simple hydrothermal method. The effects of reaction conditions on particle size, morphology, magnetic, and microwave absorption properties of the NiFe2O4/CBC composites were systematically studied. In all NiFe2O4/CBC composites, NiFe2O4 microspheres with different shapes and sizes were anchored on the surface of CBC. By adjusting size of the NiFe2O4 particles, dielectric and magnetic properties of the NiFe2O4/CBC composites could be optimized simultaneously. For the NiFe2O4/CBC sample with the average particle size of NiFe2O4 to be 4.69 nm, when the thickness was 4.42 mm, the minimum reflection loss (RLmin) could reach − 63.15 dB at 9.89 GHz. Meanwhile, the maximum effective absorption bandwidth (EABmax) was 4.91 GHz (6.31–11.22 GHz) at a thickness of 5 mm, which almost covered the whole X-band. The s-shaped hysteresis loop of the sample revealed that it had typical superparamagnetic characteristics. The possible mechanism of microwave absorption was also discussed. Our NiFe2O4/CBC composites could be used as a new and efficient microwave absorption material. •NiFe2O4/CBC (coal-based carbon) composites were successfully prepared by using microwave irradiation and hydrothermal reaction method.•By adjusting size of the NiFe2O4 particles, dielectric and magnetic properties of the NiFe2O4/CBC composites could be optimized simultaneously.•The NiFe2O4/CBC composites had typical superparamagnetic characteristics.•Due to the impedance matching and attenuation capacity, these composite materials showed excellent electromagnetic wave absorption (EMWA) performance.•With a thickness of 4.42 mm, RLmin value of the optimal composite was − 63.15 dB at 9.89 GHz, while the EAB value could reach 4.91 GHz with a thickness of 5.0 mm, which almost covered the entire X-band.