MOF-Derived Co/C and MXene co-Decorated Cellulose-Derived Hybrid Carbon Aerogel with a Multi-Interface Architecture toward Absorption-Dominated Ultra-Efficient Electromagnetic Interference Shielding

Abstract

Exploring electromagnetic interference (EMI) shielding materials with ultra-efficient EMI shielding effectiveness (SE) and an absorption-dominated mechanism is urgently required for fundamentally tackling EMI radiation pollution. Herein, zeolitic imidazolate framework-67 (ZIF-67)/MXene/cellulose aerogels were first prepared via a simple solution mixing-regeneration and freeze-drying process. Subsequently, they are converted into electric/magnetic hybrid carbon aerogels (Co/ C/MXene/cellulose-derived carbon aerogels) through a facile pyrolysis strategy. ZIF-67-derived porous Co/C could provide the additional magnetic loss capacity. The resultant electric/magnetic hybrid carbon aerogels exhibit a hierarchically porous structure, complementary electromagnetic waves (EMWs) loss mechanisms, and abundant heterointerfaces. The construction of a porous architecture and the synergy of electric/magnetic loss could greatly alleviate the impedance mismatching at the air−specimen interface, which enables more EMWs to enter into the materials for consumption. Moreover, numerous heterointerfaces among Co/C, Ti 3 C 2 T x MXene, and cellulose-derived carbon skeleton induce the generation of multiple polarization losses containing interfacial and dipole polarization, which further dissipate the EMWs. The resultant electric/magnetic hybrid carbon aerogel with a low density (85.6 mg/cm 3 ) achieves an ultrahigh EMI SE of 86.7 dB and a superior absorption coefficient of 0.72 simultaneously. This work not only offers a novel approach to design high-performance EMI shielding materials entailing low reflection characteristic but also broadens the applicability of electric/magnetic hybrid carbon aerogels in aerospace, precision electronic devices, and military stealth instruments.

Cu-Metal Organic Framework Derived Multilevel Hierarchy (Cu/CuxO@NC) as a Bifunctional Electrode for High-Performance Supercapacitors and Oxygen Evolution Reaction

“…Therefore, it illustrates that specific surface area increases with the increase in carbonization temperature; this leads to an increase in the carbon content. 45,46 The carbon-supported metal oxides shorten the electrolyte ions and diffusion path and allow for sufficient interaction between the active materials and the electrolyte ions. 47 The earlier research demonstrates that nitrogen might improve the electrical conductivity and capacitive behavior of nanosheet-like carbon materials, leading to superior performance for supercapacitors and electrocatalytic applications.…”

High-Efficiency Electromagnetic Interference Shielding from Highly Aligned MXene Porous Composites via Controlled Directional Freezing

“…When the incident electromagnetic wave propagates to the surface of the MSC PCMs, due to the impedance mismatch between the PCMs and the external air, a small portion of the electromagnetic wave is reflected, and the vast majority of the electromagnetic waves propagate to the interior of the PCMs. 69 Inside the material, electromagnetic waves are dissipated by multiple reflections and multiple scatterings within the microporous cellular framework of MXene nanosheets enhanced by CNTs and SA. In addition, the formation of conductive networks inside the PCMs provides conductive paths for electron migration and leapfrogging, and thus conductive losses occur.…”

“…In order to describe more specifically the shielding mechanism, Figure h shows a mechanism diagram of the propagation process of incident electromagnetic waves in the MSC PCMs. When the incident electromagnetic wave propagates to the surface of the MSC PCMs, due to the impedance mismatch between the PCMs and the external air, a small portion of the electromagnetic wave is reflected, and the vast majority of the electromagnetic waves propagate to the interior of the PCMs . Inside the material, electromagnetic waves are dissipated by multiple reflections and multiple scatterings within the microporous cellular framework of MXene nanosheets enhanced by CNTs and SA.…”

Carbonized Syndiotactic Polystyrene/Carbon Nanotube/MXene Hybrid Aerogels with Egg-Box Structure: A Platform for Electromagnetic Interference Shielding and Solar Thermal Energy Management

“…Interlayer spacers were usually introduced to solve the above-mentioned issues. For instance, zero-dimensional (0D) nanoparticles, − one-dimensional (1D) nanotubes/nanowires, ,,, 2D nanosheets, − or a combination of these materials − have been incorporated between MXene layers. For practical purposes, MXene-based EMI shielding materials were fabricated using layer-by-layer assembly techniques, ,,, freeze-casting, ,,,, and segregated compositing. − …”