A Novel Low-Density-Biomass-Carbon Composite Coated with Carpet-like and Dandelion-Shaped Rare-Earth-Doped Cobalt Ferrite for Enhanced Microwave Absorption

• Published in: Molecules (Basel, Switzerland) Vol. 29; no. 11; p. 2620
• Main Authors: Shang, Tao, Zhu, Hongwei, Shang, Yichun, Wu, Ruixia, Zhao, Xuebing
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 02.06.2024; MDPI
• Subjects: Biomass; Carbon; Chief financial officers; Cobalt; Composite materials; Electric waves; Electromagnetic radiation; Electromagnetic waves; Electromagnetism; ferrite; Force and energy; Iron compounds; microwave absorption; Morphology; porous carbon; rare-earth doping; Raw materials; Canada; China; biomass; porous carbon; ferrite; rare-earth doping; microwave absorption; special morphology; composite materials
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules29112620

A novel low-density composite for the absorption of microwaves was prepared by loading La-doped spinel cobalt ferrite (La-CFO) onto biomass carbon (BC) derived from corn stalks using a hydrothermal method. This composite (La-CFO@BC) not only maintained the advantageous properties of low density and abundant porosity, but also exhibited a unique morphology, with La-CFO displaying a carpet-like structure interspersed with dandelion-shaped particles. The incorporation of La-CFO effectively tuned the electromagnetic parameters of the composite, thereby improving its impedance-matching attributes and its ability to absorb microwave radiation. At a frequency of 12.8 GHz for electromagnetic waves and with a thickness of 2.5 mm, La-CFO@BC demonstrated remarkable performance in microwave absorption, attaining a noteworthy minimum reflection ( ) of -53.2 dB and an effective absorption bandwidth (EAB) of 6.4 GHz. Furthermore, by varying the thickness of the La-CFO@BC within the range of 1.0 to 5.5 mm, the EAB could be broadened to 13.8 GHz, covering the entire X-band, the entire Ku-band, and a substantial portion of the C-band. This study demonstrated that La-CFO@BC was a promising alternative for electromagnetic wave attenuation, which offered superior performance in microwave absorption.