Lightweight MXene-Based Hybrid Aerogels with Ultrabroadband Terahertz Absorption and Anisotropic Strain Sensitivity

Abstract

MXene aerogels with a three-dimensional (3D) network structure have attracted increasing attention for lightweight electromagnetic wave absorbers. It is intriguing to expand their absorption band, i.e., to the booming terahertz (THz) region, and explore multifunctionality. Herein, we assemble MXene (Ti 3 C 2 T x )-based hybrid aerogels into an aligned lamellar architecture using a bidirectional freezing technique. With air pore size and lamellar layer spacing comparable to THz wavelengths, high porosity of the aerogels allows nearly isotropic absorption of 99% and electromagnetic interference (EMI) shielding effectiveness with a remarkable value of 57.5 dB, in the ultrabroad bandwidth ranging from 0.5 to 3.0 THz. Simultaneous, strain-sensing response reflects the macroscopic anisotropy of the network structure of the aerogels. The improved sensitivity is measured for the out-oflamellar layer plane under 0−30% strain. The corresponding long-term stability and durability persist over 120 stretching−releasing cycles. Our findings thus not only expand multiple functions of MXene in an anisotropic 3D macroscopic form but also clarify its nearly isotropic absorption in the THz band.

3D Architectural MXene‐based Composite Films for Stealth Terahertz Electromagnetic Interference Shielding Performance

“…[8,11,[24][25][26][27][28] Due to their high electrical conductivity, MXenes exhibit multiple reflection mechanisms between layers and contribute to secondary interferences, which can be rectified by either structural design or composite strategies. [18] Various structural designs such as thin film, [4,11,19,29] solid pellet, [30] porous film, [31] foam, [7,8,32,33] sponge, [26,34] fabric, [35] aerogel, [36,37] membrane, [9,16,38] and paint [39] are explored for MXenes to attenuate electromagnetic interference. Structural design helps to produce a higher absorption-to-transmission ratio, interfacial scattering, and multiple reflective surfaces, successfully mitigating secondary EMI pollution.…”

An artificially re-structured PEDOT:PSS/konjac glucomannan sponge toward high-performance electromagnetic interference shielding from gigahertz to terahertz bands

“…(f) Tan d, (g) reflection loss value and (h) absolute value of 1 − Z of CG and PPK sponges. (i) Direct comparison of the THz EMI shielding performance of PPK sponges (marked as star) in this work with those of prevailing materials[14][15][16]45,[58][59][60][61][62][63][64][65] (marked as circles and squares), including MXene-dominated, carbon-dominated, metal-dominated and semiconductor-dominated materials.…”