In-situ generated Ni/Ni3Si to enhance electromagnetic wave absorption properties of Ni/PDCs/biomass ceramic composites

In recent years, electromagnetic wave (EMW) absorbing materials derived from biomass materials have been widely concerned because of their light weight and high efficiency. Here, Ni/PDCs/biomass ceramic composites absorbing material was prepared by a simple suspension impregnation-in-situ reduction carbonization process and polymer-derived ceramics (PDCs) with peanut shell as the absorbing matrix and NiO doped in polysiloxane as the precursor solution. The synergistic effect of Ni/PDCs could effectively adjust the impedance matching of the composite, and the BET results shown that the prepared Ni/PDCs/biomass ceramic composites had a hierarchical porous structure, which could not only provide a large number of heterogeneous interfaces, but also enhance the interface polarization, dipole polarization and multiple reflection loss of the absorbing material. The sample of NPP-1 possessed good EMW absorbing performance when the content of NiO was 1 % and the filler was 50 %, the minimum reflection loss (RLmin) reached - 66.38 dB at 1.74 mm, and the effective absorption bandwidth (EAB) was 3.54 GHz (14.46-18 GHz) at 1.45 mm. In this work, the electromagnetic parameters of biomass materials were adjusted by polymer conversion ceramics and metal oxides, which provided another feasible scheme for enhancing the absorbing properties of biomass materials.