Construction of Bimetal Heterostructures on Bamboo Fiber Carbon: Triple-Conductive Structure and Enhanced Microwave Absorption

Abstract

The effective coupling of magnetic loss and dielectric loss has become a mainstream method for achieving high-performance microwave absorption (MA) materials. Herein, wasted bamboo fibers were applied to prepare carbon-based magnetic composites through high-temperature in-situ growth of different bimetallic nanoparticles (FeCo, CoNi and FeNi) on bamboo fiber carbon (BFC). The surface morphologies, phase information, and electromagnetic properties of different bimetal-decorated BFC composites were investigated. Modulation of bimetal species and FeCo molar ratio affords the composites different MA performances. Remarkably, when molar ratio of Fe3+ and Co2+ was 1:2, a broad effective absorption bandwidth of 5.6 GHz and a RLmin value of -57.3 dB at a small thickness of 1.86 mm were achieved with the mass loading of only 15 wt%. Such excellent performances were benefited from a unique triple-conductive structure that bimetallic core-shell nanoparticles embedded within carbon nanowires decorated on the BFC, realizing perfect impedance matching as well as strong attenuation ability. This work would provide a novel perspective for value-added utilization of bamboo resource and prevention of microwave pollution.

Keywords: Bamboo fibers, Bimetal nanoparticles, Triple-conductive structure, Microwave absorption