Cation Bimetallic MOF Anchored Carbon Fiber for Highly Efficient Microwave Absorption

• Published in: Small (Weinheim an der Bergstrasse, Germany) Germany), 2024-08, Vol.20 (32), p.e2312135-n/a
• Main Authors: Zhang, Feng, Li, Nan, Shi, Jun‐Feng, Wang, Yue‐Yi, Yan, Ding‐Xiang, Li, Zhong‐Ming
• Format: Article
• Language: English
• Subjects: Bend strength; Bimetals; carbon fiber; Carbon fibers; Coating; Compressive strength; defect‐induced polarization; Dielectric loss; Dielectric strength; Epoxy resins; Impedance matching; Mechanical properties; Metal-organic frameworks; Microwave absorbers; Microwave absorption; Modulus of elasticity; NiCoMOF
• ISSN: 1613-6810; 1613-6829; 1613-6829
• DOI: 10.1002/smll.202312135

Carbon fiber (CF) is a potential microwave absorption (MA) material due to the strong dielectric loss. Nevertheless, owing to the high conductivity, poor impedance matching of carbon‐based  materials results in limited MA performance. How to solve this problem and achieve excellent MA performance remains a principal challenge. Herein, taking full advantage of CF and excellent impedance matching of bimetallic metal–organic frameworks (MOF) derivatives layer, an excellent microwave absorber based on micron‐scale 1D CF and NiCoMOF (CF@NiCoMOF‐800) is developed. After adjusting the oxygen vacancies of the bimetallic MOF, the resultant microwave absorber presented excellent MA properties including the minimum reflection loss (RLmin) of −80.63 dB and wide effective absorption bandwidth (EAB) of 8.01 GHz when its mass percent is only 5 wt.% and the thickness is 2.59 mm. Simultaneously, the mechanical properties of the epoxy resin (EP)‐based coating with this microwave absorber are effectively improved. The hardness (H), elastic modulus (E), bending strength, and compressive strength of CF@NiCoMOF‐800/EP coating are 334 MPa, 5.56 GPa, 82.2 MPa, and 135.8 MPa, which is 38%, 15%, 106% and 53% higher than EP coating. This work provides a promising solution for carbon materials achieving excellent MA properties and mechanical properties. The interfacial polarization and defect‐induced polarization generated by multiple heterogeneous interfaces optimize the electromagnetic wave absorption performance of the CF@NiCoMOF‐800 composite.