-PW11Fe(Co/Ni)/BC derived carbon fiber based nanocomposites for high efficiency electromagnetic wave absorption via synergistic effects of polarization and conductance

In order to enhance the wave-absorbing performance of dielectric/carbon fiber based wave-absorbing materials and explore the dissipative mechanism of electromagnetic wave (EMW), this study utilizes liquid diffusion of K4PW11O39Fe(III)(H2O) (alpha-PW11Fe), K5PW11O39Co(II)(H2O) (alpha-PW11Co), K5PW11O39Ni(II)(H2O) (alpha-PW11Ni) and bacterial cellulose (BC), as well as high temperature carbonization strategy to prepare polycrystalline polyphase transition metals and their compounds with three dimensional porous conductive network structure loaded carbon fiber based nanocomposites wave-absorbing materials. By changing the element type, drying mode and filling amount, we can achieve the tunability of electromagnetic parameters and absorbing properties. Impressively, the best synthesized sample 20 %-alpha-PW11Ni/BC derived carbon fiber based nanocomposites has excellent EMW absorption properties, with a maximum reflection loss (RL) of -68.1 dB at 2.6 mm matching thickness. The effective absorbing bandwidth (EAB) is 7.2 GHz, and the RL less than -10 dB in the frequency band of 2.2-5.0 mm thickness is 5.3 to 18.0 GHz. The excellent absorbing performance is attributed to the synergy of polarization and conductance, balanced impedance matching, good interface/dipole polarization, and multiple reflections and scattering. Therefore, the prepared composite has a broad application prospect in the field of EMW absorption, and provides a new idea for the design of new efficient absorbing materials.