Polycrystalline Multiphase Transition Metal Tungsten and Oxide Nanoparticles with Np-Doped C/Magnetic Mxene as Broadband and Efficient Electromagnetic Wave Absorbing Materials

Abstract

MXene materials have a number of characteristics, including two-dimensional wide-contact interfaces, high surface area, excellent electrical conductivity, and many functional groups that make it good candidates for electromagnetic wave stealth applications. The current studies focus on solving the problems of impedance mismatch and susceptibility to stacking. The objective of the research is to initiate the polymerisation of pyrrole monomers with phosphotungstic acid under different oxidant conditions and then under a high-temperature carbonization, nitrogen-phosphorus doped carbon@ polycrystalline multiphase tungsten and oxides (NPC@W(O)x) nanomaterials is formed. The nitrogen-phosphorus doped carbon serves to polarise and induce conductivity loss, while the phosphotungstic acid is employed to produce dielectric W(O)x nanoparticles, which are anchored onto the NPC. NPC@W(O)x and magnetic Ni nanoparticles are embedded in the surface and interlayers of the MXene network (MXene/NPC@W(O)x/Ni nanocomposites), which both improves impedance matching and prevents stacking. MXene/NPC@W(O)x/Ni nanocomposites have excellent wave-absorbing properties due to dipole polarisation caused by the presence of abundant defects, etc. During high-temperature treatment and space charge polarisation caused by the formation of multiple heterogeneous interfaces in the multicomponent materials. Among the nanocomposites prepared with FeCl3 as the oxidant, those containing MXene/NPC@W(O)x/Ni exhibit excellent electromagnetic absorption properties at very thin thicknesses. The MXene/NPC@W(O)x/Ni nanocomposites-45 wt% have a minimum reflection loss value of -63.8 dB at a thickness of only 2.0 mm, corresponding to an absorption bandwidth of 5.5 GHz, also the effective bandwidth can reach 9 GHz in the low thickness range of 1.7~3.5 mm.

Keywords: Tungsten transition metal and oxides, Polycrystalline multiphase, Multiple heterogeneous interfaces, Broadband