Controllable Synthesis of Mo3C2 Encapsulated by N-Doped Carbon Microspheres to Achieve Highly Efficient Microwave Absorption at Full Wavebands: From Lemon-like to Fig-like Morphologies

Yanli Nan; Zihan Zhang; Zhaoyu Wang; Hudie Yuan; Yun Zhou; Jian Wei

doi:10.1021/acs.inorgchem.2c00533

Controllable Synthesis of Mo₃C₂ Encapsulated by N-Doped Carbon Microspheres to Achieve Highly Efficient Microwave Absorption at Full Wavebands: From Lemon-like to Fig-like Morphologies

Inorg Chem. 2022 Apr 25;61(16):6281-6294. doi: 10.1021/acs.inorgchem.2c00533. Epub 2022 Apr 12.

Authors

Yanli Nan¹, Zihan Zhang¹, Zhaoyu Wang¹, Hudie Yuan¹, Yun Zhou², Jian Wei¹

Affiliations

¹ School of Materials Science and Engineering, Shaanxi Key Laboratory of Nano Materials and Technology, Xi'an University of Architecture and Technology, Xi'an 710055, China.
² School of Medical Information and Engineering, Southwest Medical University, Lu Zhou 646000, China.

PMID: 35412830
DOI: 10.1021/acs.inorgchem.2c00533

Abstract

Mo₃C₂@N-doped carbon microspheres (Mo₃C₂@NC) have been discovered to be a family of superior microwave absorbing materials. Herein, Mo₃C₂@NC was synthesized through a simple high-temperature carbonization process by evaporating a graphite anode and Mo wire in Ar and N₂ atmospheres with an N-doping content of 6.4 at. %. Attributing to the self-assembly mechanism, the number of Mo wires inserted into the graphite anode determined the morphologies of Mo₃C₂@NC, which were the unique lemon-like (1- and 2-Mo₃C₂@NC) and fig-like (3-, 4-, and 5-Mo₃C₂@NC) microstructures. 1- and 2-Mo₃C₂@NC exhibited powerful reflection losses (RLs) of -45.60, -45.59, and -47.11 dB at the S, C and X bands, respectively, which corresponded to thinner thicknesses. 3-, 4-, and 5-Mo₃C₂@NC showed outstanding absorption performance at the C, X, and Ku bands, respectively, with each value of a minimum RL less than -43.00 dB. In particular, the strongest RL (-43.56 dB) for 5-Mo₃C₂@NC corresponded to an ultrathin thickness of 1.3 mm. In addition, the maximum effective absorption bandwidth was 6.3 GHz for 4-Mo₃C₂@NC. After analysis, all Mo₃C₂@NC samples showed well-matched impedance due to the enhanced dielectric loss caused by the unique carbon structure and moderate magnetic loss derived from the weak magnetic property of Mo₃C₂. More importantly, the unique lemon-like and fig-like microstructures created sufficient interfaces and differentiated multiple reflection paths, which greatly contributed to the strong microwave absorptions at full wavebands. In full consideration of the simple preparation method and tunable absorption properties, Mo₃C₂@NC composites can be regarded as excellent electromagnetic wave absorption materials.