Ultralight Hierarchically Structured RGO Composite Aerogels Embedded with MnO₂/Ti₃C₂T_x for Efficient Microwave Absorption

Abstract

Although intensive efforts have been devoted to fabricating Ti3C2T x MXene composites for microwave absorption, it remains a great challenge to achieve excellent MA performance at low loading and thin thickness. Herein, a three-dimensional (3D) lightweight hierarchically structured MnO2/Ti3C2T x /RGO composite aerogel with abundant heterointerfaces was fabricated via a hydrothermal and chemical reduction self-assembly method. The RGO aerogel embedded with laminated MnO2/Ti3C2T x provides a lot of heterogeneous interfaces, 3D porous interconnected conductive networks, and reasonable combination of various loss materials for rich interfacial polarization, conductivity loss, multiple reflections and scattering, and good impedance matching. Benefiting from the synergy of different loss mechanisms, the maximum reflection loss (RL) is up to −66.5 dB (>99.9999% energy absorption) at only 10 wt % loading and 2.0 mm thickness, and even at only 1.5 mm thickness, the maximum RL value remains at −36 dB (>99.9% energy absorption). The work provides a promising route to construct 3D hierarchically heterogeneous composite aerogels for efficient MA at thin thickness and low loading.

Plasma Engineering toward Improving the Microwave-Absorbing/Shielding Feature of a Biomass-Derived Material

“…Figure exposes the Cole–Cole plot, impedance matching ( Z ), eddy current loss ( C 0 ), and attenuation constant (α). Each circular arc emerged by drawing ε′ ( x axis) versus ε″ ( y axis), when its center is between the x axis and curve, testifying to one polarization mechanism; meanwhile, its radius attests to the polarization intensity, governed by the Debye relaxation theory. − The number of semicircles clarifies the number of polarization types. Evidently, CO 2 treatment boosted the polarization types as a result of the emergence of various defects by exhausting the coupled oxygen- and nitrogen-containing functional groups and rearranging the chemical species, elevating the dipole polarization types; meanwhile, the reductive process under the H 2 /Ar atmosphere reduced the polarization intensity compared to the Ar-treated sample.…”

Glycine–Ti3C2Tx Hybrid Material Improves the Electrochemical Corrosion Resistance of a Water-Borne Epoxy Coating

“…MXene materials are generally composed of carbon, nitrogen, or carbon–nitrogen compounds of transition metals, with high specific surface area and high electrical conductivity . Ti 3 C 2 T x is the most widely studied MXene material, which can be used in many fields, such as electrochemistry, battery, thin film, etc. − Ti 3 C 2 T x has a high specific surface area and surface active groups and has a bright application prospect in the field of corrosion protection, but at present, there are few studies on Ti 3 C 2 T x in the field of corrosion protection. Zhao et al dispersed Ti 3 C 2 T x into the water-borne epoxy coating .…”

Lightweight, Elastic, and Superhydrophobic Multifunctional Organic–Inorganic Fibrous Aerogels for Efficient Oily Wastewater Purification and Electromagnetic Microwave Absorption

“…Recently, carbon-based aerogels have been developed as the most promising microwave-absorbing materials due to their unrivaled structural advantages. The characteristics of the macroscopic 3D porous structure, rich porosity and remarkable electronic conductivity of carbon-based aerogels, can provide tortuous transmission pathways, abundant polarization sites, and intensive conductive networks for the efficient attenuation of microwaves. − However, in the future, the application of a carbon-based aerogel microwave absorber may be extended to a more complex practical application environment, which requires them to possess multifunctional property. , For example, the carbon-based aerogel microwave absorber with superhydrophobicity will enable them to apply in extreme humid conditions, or even apply as an oil/water separation material. , Besides, the carbon-based aerogel microwave absorber with excellent thermal stability and nonflammability can protect electronic devices from burning or damage. − Multifunctionalization of advanced microwave absorbers is the future development trend. However, the integration of multiple functions into one material remains a great challenge, which depends on the creative design of the material in terms of structure, component, geometry, surface state, and/or synergistic effect …”