Nano Bimetallic@Carbon Layer on Porous Carbon Nanofibers with Multiple Interfaces for Microwave Absorption Applications

Abstract

Porous carbon fibers (FeCo@C-PCFs) hybrids are fabricated by a two-step process involving the electrospinning followed by heat treatment, in which several steps are involved including the reduction of polyvalent metal ions, the produced alloy nanoparticles are encapsulated into porous carbon substrate, yielding the FeCo-polyacrylonitrile networks (FeCo-PAN) that are formed in situ and function as the building blocks. After altering feeding proportion of Co 2+ and Fe 3+ , the formation of FeCo@ C-PCF compounds could be controlled. More importantly, FeCo alloys seem to have higher chemical stability. With different graphitization degrees, FeCo@C-PCF compounds were proven to be outstanding microwave (MW) absorbent including thickness, effective bandwidth, and reflection loss (RL). The maximum RL values reached −56 dB at 1.85 mm and broadest bandwidth was 8.3 GHz.

Porous carbon materials for microwave absorption

“…Especially, it should be noted that some interesting technologies such as arc-discharge plasma technology, electrospinning technology, and microwave-assisted methods are also utilized for fabricating PC, which provides a new strategy for the development of microwave absorbers. 126,129,130 For example, Li et al synthetized a tremella-like porous NiCo/C composite through a microwave-assisted method, and the fabrication time was greatly decreased. 126 Table 2 summarizes the MA properties of recent PC-based composite absorbers.…”

Preparation of Ni/C porous fibers derived from jute fibers for high-performance microwave absorption

“…Finally, in the alternating microwave eld, porous carbon nanobers can provide a direct pathway for free electron transfer, and the transmitted microwave will be reected and scattered in the porous media, which eventually can be absorbed and exhausted. 11 The SEM images of the porous bers/paraffin composites were shown in Fig. S6.…”

“…Ji et al prepared FeCo/porous carbon ber composite through electrospinning and subsequent heat treatment, and a minimum RL value of À56 dB was achieved. 11 The excellent microwave absorption performance was mainly attributed to the strong dielectric loss and magnetic loss as well as the porous structure of the material. Although some progress has been made in the exploration of carbon-based composite MAMs, the carbon matrix materials used were mainly carbon bers, carbon nanotubes, graphene and metal-organic framework compounds.…”

“…Although some progress has been made in the exploration of carbon-based composite MAMs, the carbon matrix materials used were mainly carbon bers, carbon nanotubes, graphene and metal-organic framework compounds. [10][11][12][13][14][15] The preparation method with cheap raw materials, simple process, and adjustable magnetic content in a wide range is still a challenging topic and difficulty in the research eld of carbon-based MAMs.…”

“…shows typical XRD patterns of the synthesized samples PCF, Ni/C-0.2, Ni/C-0.5, and Ni/C-1.0. For PCF, the broad peak at about 15 -30 indicates that the carbon component is amorphous 11,26. For Ni/C-0.2, Ni/C-0.5, and Ni/C-1.0, the diffraction XRD patterns of PCF, Ni/C-0.2, Ni/C-0.5, and Ni/C-1.0.peaks at 2q ¼ 44.51 , 51.85 , and 76.37 can be assigned to the (111), (200) and (220) crystalline planes of Ni (JCPDS No.…”