Wave Absorption Materials Research Articles

In situ construction of Co@nitrogen-doped carbon/Ni nanocomposite for broadband electromagnetic wave absorption

The tunable multicomponent synergistic loss mechanism and multiple heterogeneous interfaces of magnetic carbon-based composites have emerged as the efficient electromagnetic wave absorbing (EMWA) materials. Herein, the Ni(OH)2/ZIF-67 precursors were synthesized via the hydrothermal and liquid-phase deposition methods, and then carbonized at different temperature under N2 atmosphere to obtain Co@nitrogen-doped carbon/Ni (Co@NC/Ni) nanocomposites. The metallic components with good dispersion property provided magnetic loss and improved impedance matching. Meanwhile, they also acted as catalysts to induce the formation of graphitized carbon, enhancing the conductive loss. Furthermore, more heterogeneous interfaces and defects were generated inside the sample, which promotes dielectric loss. Therefore, the Co@NC/Ni nanocomposite (carbonized at 600 °C) exhibited excellent EMWA performance with a minimum reflection loss (RL) of −47.10 dB, and the effective absorption bandwidth (RL ≤ −10 dB) can reach 6.84 GHz at 2.5 mm with a filling ratio of 30%. This work provides a heterogeneous interface construction strategy for the future application of high-performance magnetic carbon based EMWA materials.

Ni nanospheres coated with tunable carbon shells for dielectric-controlled superior electromagnetic wave absorbing

To obtain high-efficiency electromagnetic wave absorbing (EMA) material with strong reflection loss ( RL ) and wide effective absorbing bandwidth (EAB), Ni particles are successfully prepared in this work by a liquid phase reduction approach, and Ni@C is subsequently designed and fabricated through combined polymerization and carbonization process. The pristine Ni exhibits outstanding EMA performances in middle- and high-frequency with a maximum RL ( RL max ) of 62.3 dB (2.3 mm) at K u band and an EAB of 10.9 GHz (5.6–16.5 GHz) at 3.0 mm, covering 75% K u (12–18 GHz), 100% X (8–12 GHz) and 60% C (4–8 GHz) band. Such a superior property is attributed to the dielectric losses derived from interface polarization, dipole polarization and conduction loss, along with magnetic losses comes from natural and exchange resonance. An introducing of carbon shell with manipulated thicknesses induces positive enhancement in dielectric losses. Meanwhile, core-shell structures enable multiple scattering and reflection of microwaves. Thus, Ni@C spheres exhibit significantly enhanced EMA performances in low-frequency covering S (2–4 GHz) and C band with an RL max at 4.4 GHz reaching 64.4 dB (Ni@C-0.4) and an RL max at 2.6 GHz reaching 59.3 dB (Ni@C-0.6). Therefore, Ni and Ni@C demonstrate a unique blend of favorable EMA performances, which are promising for next-generation intelligent EMA systems.

Achieving excellent electromagnetic wave absorption property by constructing VO2 coated biomass carbon heterostructures

Lightweight, high-efficiency and low-cost electromagnetic wave absorption (EMA) material is playing an increasingly critical role in the areas of mobile communications, electronic machines and military science and technology. Heterostructures of biomass-derived porous carbon (BPC) from chestnut needle coated by VO 2 were constructed. Microstructure, morphology as well as EMA performance of as-prepared VO 2 /BPC composites were explored. The special porous structure of BPC-based composites boosted multi-reflections and scattering of EM wave. The higher surface area provided more channels for charge transfer, benefiting the dissipation of EM wave energy. The formed VO 2 was uniformly dispersed in BPC matrix resulting in more polarization loss. Additionally, the reduzate of VO 2 improved the impedance matching further optimizing the EMA performance immensely. With the joint action of excellent impedance matching and attenuation capacity, the VO 2 /BPC composites exhibited favorable EMA performance that the minimum reflection loss of −54.0 dB was achieved with wide effective absorption bandwidth of 2.5 GHz. The obtained results suggest the VO 2 /BPC composites would be a hopeful candidate for high-efficient, lightweight and green EMA material. • Preparation of EMA materials derived from natural biomass carbon. • Improved EMA performance was achieved that RL min was −54 dB. • The impedance matching and polarization loss was enhanced drastically by introduction of VO 2 . • The EMA mechanism was investigated.

Engineering polarization surface of hierarchical ZnO microspheres via spray-annealing strategy for wide-frequency electromagnetic wave absorption

• Hierarchical ZnO microspheres were successfully synthesized via spray-annealing strategy. • Pure dielectric loss ZnO materials were assembled by nanorods and nanoparticles with adjusting different aspect ratios, defects and polar faces. • Hierarchical ZnO-1 materials shown the widest efficient absorption region from 9.9 to 18.0 GHz at 2.4 mm. Regulating orientation growth plays a dominant role in enhancing dielectric properties for the electromagnetic (EM) functional materials, which faces a huge challenge in the synthesis method. By spray-annealing strategy, hierarchical ZnO microspheres assembled by ZnO nanorods and nanoparticles were successfully fabricated. With confined microsphere space and controlling crystal growth, oriented ZnO nanorods possess rich defects, Zn-polar, O-polar faces, and high permittivity. Meanwhile, temperature-dependency of exposed polarization surfaces is discovered in the semiconductor ZnO nanoparticles with evolved aspect ratios. As pure dielectric EM wave absorption material, the hierarchical ZnO microsphere exhibits adjustable complex permittivity and polarization behaviors. When the thickness is 2.4 mm, the hierarchical ZnO-1 absorber shows the widest efficient absorption (RL ≤ –10 dB) region from 9.9 to 18.0 GHz (8.1 GHz, ∼50.6% testing frequency). The minimum reflection loss (RL) of ZnO-1 can reach –31.5 dB at only 2.0 mm. Because of the outstanding dielectric loss ability and wide absorption frequency, large-scale hierarchical ZnO microspheres can be a potential EM absorption candidate.

High-performance pinecone-like MOF derivative electromagnetic wave-absorbing composite via in situ anisotropic-oriented growth

Designing multihierarchical electromagnetic wave-absorbing composite with multiphase, multieffective, and multidimensional properties is an effective way to improve absorption performance. Metal–organic frameworks (MOFs) have a high metal content and a stable carbon framework. By adjusting the metal type, organic ligand type, and precursor ratio during the preparation process, MOF materials with different morphologies can be synthesized and transferred into multihierarchical electromagnetic wave-absorbing composites via in situ pyrolysis. Herein, based on the Kirkendall diffusion effect, an in situ anisotropic-oriented growth strategy was advanced during the pyrolysis of Prussian blue, and a new magnetic carbon composite (γ-Fe2O3 @N-rGO/MWCNT) was prepared. The composite has a multihierarchical structure consisting of pinecone-like nanoflowers and a porous carbon framework. The nanoflowers are core-shell structures with γ-Fe2O3 magnetic nanoparticles as cores and nitrogen-doped reduced graphene oxides as shells interspersed in a porous carbon framework that includes intertwined multiwalled carbon nanotubes and amorphous carbon. The minimum reflection loss (RLmin) of the samples can reach up to − 59.2 dB at 5.51 GHz. The in situ anisotropic-oriented growth strategy used in this work shows great promise for the preparation of a variety of multihierarchical structure nanocomposite electromagnetic wave-absorbing materials with abundant absorption effects.

Inner phase hybridization engineering of core-shell structure confined in graphene scroll for boosting electromagnetic wave absorption

Rational manipulation of low dimensional composite materials with tunable phase hybridization and hierarchical structure is evolving as a promising strategy to boost electromagnetic (EM) wave absorption performance. Herein, a cation-π interaction-driven assembly and carbothermic reduction strategy is proposed to construct the hierarchical 0D core-shell embedded 1D reduced graphene oxide (rGO) scroll aerogels with tuning phase hybridization in the inner core as EM wave absorption materials for the first time. The metal ions can form strong cation-π interaction with CNTs and graphene oxide (GO) to drive the rolling of GO on the surface of CNTs, generating 1D scroll. During the pyrolysis, the metal ions evenly dispersed in the interlayers of graphene scroll can be in-situ reduced to produce the multiple component magnetic nanoparticles which are coated by carbon to form 0D core-shell structure and phase hybridization of the inner core can be easily regulated by the temperature. Due to the optimized interfacial polarization effect and magnetic-dielectric synergy, the aerogel obtained at pyrolysis temperature of 650 °C exhibit ultrahigh EM wave absorption performance with a minimum reflection loss of −88.70 dB with effective absorption bandwidth of 7.30 GHz at 2.99 mm, overpassing most of the known EM wave absorption materials. This work as a comprehensive research provides a deep understanding upon the primary contribution of phase hybridization and hierarchical structure, well inspiring the further development of low dimensional EM wave absorption materials.

MOF-derived core-shell structured Cu9S5/NC@Co3S4/NC composite as a high-efficiency electromagnetic wave absorber

Constructing specific microstructures and designing multicomponent composites are regarded as effective approaches to obtaining high-efficiency electromagnetic (EM) wave absorbing materials. Herein, core-shell structured Cu9S5/N-doped carbon@Co3S4/N-doped carbon (Cu9S5/NC@Co3S4/NC) composites derived from Cu3(BTC)2@ZIF-67 were synthesized by facile carbonization and sulfidation processes. The Cu9S5 particles are embedded in the interior and surface of the carbon skeleton, and the Co3S4/NC particles are uniformly distributed on the surface of the carbon skeleton. Compared with Cu9S5/NC and Co3S4/NC, the Cu9S5/NC@Co3S4/NC composite displays improved impedance matching properties and much better EM wave absorbing properties. The minimum reflection loss (RLmin) reaches −41.6 dB at 10.52 GHz with a thickness of 2 mm. In addition, the effective absorption bandwidth (EAB, RL < −10 dB) is 4.08 GHz (12.73–16.81 GHz) with un ultrathin thickness of 1.5 mm. This work offers a facile strategy for synthesizing MOF-derived metal sulfides/carbon composites as EM wave absorption materials with strong absorption properties, a wide absorption bandwidth and ultrathin thickness.

Architectural Design and Microstructural Engineering of Metal–Organic Framework‐Derived Nanomaterials for Electromagnetic Wave Absorption

Metal–organic frameworks (MOFs) derivatives are developing family of functional materials for electromagnetic wave (EMW) absorption. Their tailored structures, controllable compositions, high porosity, and versatile functions offer immense advantages for the construction of excellent EMW absorption materials. Nevertheless, it is crucial and challenging to understand the unique role of rationally designing art and tailoring the microstructures of MOF‐derived materials for EMW absorption. In this review, advances in rational architectural design strategy and the elaborate control of microstructures are outlined to promote the EMW absorption performance of MOF‐derived materials. In addition, the derived key information regarding the superiority and composition–structure–performance relationships of the engineered MOF‐derived materials with advanced components and nanostructures is comprehensively summarized. Finally, the insight into the challenges of future development in MOF‐derived EMW absorption materials is presented.

Hierarchical core-shell FeS2/Fe7S8@C microspheres embedded into interconnected graphene framework for high-efficiency microwave attenuation

With the imminent era dominated by high-tech electronic products, the development of high-efficiency electromagnetic wave absorption materials has become a critical task. Rational component regulation and structural design are considered to be effective methods to optimize the electromagnetic wave absorption performance of materials. Herein, we first prepared a Fe-PBA@ PDA@GO precursor via solvothermal method; then, vulcanization was used to develop a FeS2/Fe7S8@C@rGO composite with a core-shell heterostructure, in which core-shell FeS2/Fe7S8@C microspheres were embedded on the wrinkled reduced graphene oxide layer. FeS2/Fe7S8@C@rGO, as a multi-component composite, demonstrates superior impedance matching and can thus capture more electromagnetic waves, while the multiple losses facilitate the dissipation of incident electromagnetic waves. Concretely, FeS2/Fe7S8@C@rGO can display significant attenuation of incident electromagnetic waves through multi-interface polarization, dipole polarization, resonance loss and eddy current loss. Additionally, the three-dimensional hierarchical structure not only improves the conductive loss, but also promotes multiple reflections and scattering. The FeS2/Fe7S8@C@rGO composite exhibits a minimum reflection loss of −62.7 dB and an effective absorption broadband (6.1 GHz) with a filler loading of 20 wt% at 2.2 mm, and the effective absorption bandwidth reaches 7.6 GHz at a layer thickness of 2.5 mm. These results provide a valuable reference for the preparation of high-performance microwave absorbers through composition adjustment and controlled structural design.

Single source precursor derived SiBCNHf ceramic with enhanced high‐temperature microwave absorption and antioxidation

Electromagnetic (EM) wave-absorbing materials with high-temperature-resistance are urgently desirable to eliminate EM interference in extreme conditions. Precursor derived ceramics (PDC) route is being evolved as an effective strategy to solve the puzzle. Herein, a single source hyperbranched polyborosilazane precursor containing hafnium (hb-PBSZ-Hf) is introduced and the SiBCNHf ceramic is obtained by further pyrolysis. The micro-sized tissues including HfC, SiC, HfB2 nanocrystals and segregated carbons are in situ generated during annealing which not only increase EM wave absorption ability (minimum reflection coefficient (RCmin) is -56.71 dB with a thickness of 2.5 mm, effective absorption bandwidth (EAB) is 3.4 GHz), but also improve antioxidation property (less than 2 wt.% mass fluctuation at 1400 °C in air). Theoretical simulation of complex permittivity suggests that SiBCNHf ceramic has an RCmin of less than -5 dB for the whole X-band even at 1100 °C. Such SiBCNHf ceramic with superior high-temperature-resistance and antioxidation performance derived from single source precursors possesses great potential for EM wave absorbing coatings in high-temperature and harsh environments.

Ni/Ni3ZnC0.7 modified alginate-derived carbon composites with porous structures for electromagnetic wave absorption

Electromagnetic wave (EMW) absorption materials with both high-performance and low-cost are demanded to reduce unwanted noise at microwave communication frequencies. Herein, Ni/Ni3ZnC0.7 modified alginate-derived carbon (Ni/Ni3ZnC0.7/C) composites were successfully prepared by constructing a Ni2+-Zn2+-alginate gel, followed by freeze-drying and carbonization processes. The co-introduction of nickel and zinc greatly improved EMW absorption properties. By adjusting the amounts of Ni2+ and Zn2+ ions, Ni/Ni3ZnC0.7/C composites with excellent impedance matching and EMW absorption performance were realized, evidenced by a maximum reflection loss of −40.2 dB (14.8 GHz, 2.0 mm) and an effective absorption bandwidth of 5.4 GHz (12.6–18.0 GHz, 2.0 mm). This work provides a very simple and green strategy for designing lightweight and high-performance EMW absorbers offering considerable potential for practical applications.

In situ construction of hierarchical core-shell SiCnws@SiO2-carbon foam hybrid composites with enhanced polarization loss for highly efficient electromagnetic wave absorption

The drawbacks of single loss capability and skin effect severely impede the electromagnetic (EM) wave absorption performance of carbon-based materials. Developing a rational hierarchical structure with high efficiency and facile method to optimize impedance matching and improve EM wave absorption performance still remains challenge. Herein, SiCnws/carbon foam (SCF) composites with hierarchical structure, were successfully prepared by chemical vapor deposition method. The core shell structure of SiCnws@SiO2 was grown on the scaffold and inside of the cell structure in CFs. Significantly, the amount of SiCnws can be modulated by the growth temperature. Benefiting from the impedance gradient structure, coupled with interface polarization dominated loss mechanism jointly promoted the excellent EM wave absorption performance. Specifically, when the growth temperature is 1400 °C, the SCF composite achieved an optimal reflection loss value of −55.8 dB at 10.30 GHz with a thickness of 4.35 mm and a wide effective absorption bandwidth of 3.97 GHz at 3.71 mm. Meanwhile, in-situ growth of SiCnws in CFs substantially increased the compressive strength to 21.08 MPa. This work paves a new avenue to develop highly efficient EM wave absorption materials with hierarchical structures.

Effect of rare earth doping on magnetic and dielectric properties of NiZnMn ferrites

In present work, RE0.01Ni0.3Zn0.4Mn0.3Fe2O4 (RE=Fe, La, Nd, Sm, Gd, Dy, Yb) ferrites with strictly controlled main composition were prepared. X-ray diffraction analysis shows that the lattice constant decreases with the increase of atomic number of rare earth. The infrared spectra demonstrate the changes of tetrahedral and octahedral bonds. The saturation magnetization is about 74 emu/g and initial permeability is about 120 for undoped ferrite. They decrease slightly after rare earth doping, but the impact of different rare earth on Ms is same. The Curie temperature of almost all samples is 262 ℃. Zero field cooling-field cooling curves demonstrate the existence of spin glass state or superparamagnetism at high temperature. Sm, Gd and Dy doped ferrites have special dielectric properties with more relaxation processes. Appropriate rare earth doping greatly improve the cut-off frequency, dielectric constant for MHz device materials and dielectric loss for GHz electromagnetic wave absorption materials.

In situ-derived carbon nanotubes decorated the surface of CoxNiy@C composites from MOFs for efficient electromagnetic wave absorption

The in situ formation of interconnected carbon nanotubes (CNTs) networks on the surfaces of metal-organic framework (MOF) derivatives is an efficient method for rationally constructing heterogeneous interfaces and developing high-performance electromagnetic wave absorption materials. A series of CoxNiy @C composite absorbers with abundant CNTs on their surfaces prepared by pyrolyzing MOF precursors in an Ar atmosphere is reported in this study. The S-3 composite absorber had a distinct structural morphology, and optimal wave absorption performance was obtained when the final pyrolysis temperature was 800 °C. At matched thicknesses of 2.0 mm and 3.5 mm, an effective absorption bandwidth (EAB) of 4.5 GHz and a minimum reflection loss (RLmin) of −43.5 dB were achieved when the absorber filling ratio was 15 wt%. This strategy and the results reported in this study are anticipated to encourage future studies into the controlled growth of metal-catalyzed CNTs and inspire new ideas for designing and preparing enhanced microwave absorber materials at the micro-nano scale.

Design of an Optically Transparent Microwave Absorber Based on Coding Metasurface

In this paper, a metamaterial absorber with a checkerboard patterned ITO (indium tin oxide) film as the surface is obtained by using flexible and optically transparent wave-absorbing material ITO–PET (polyethylene terephthalate), and a coding arrangement of two basic coding units based on the APS-PSO (Array Pattern Synthesis -Particle Swarm Optimization) algorithm. The surface structure of the absorber consists of ITO rectangular patch structures and ITO circular patch structures (110 Ω/sq). The ITO rectangular patch structures and ITO circular patch structures are symmetrical. The middle layer is made up of two layers of PET and one layer of PMMA, and the bottom surface is covered with a layer of low square resistance ITO film (8 Ω/sq). The experimental results, which are consistent with the simulation results, show that the absorber has superior performance: over 90% absorptance in the 5.06–9.01 GHz band, high transmittance, and a −10 dBsm RCS (radar cross-section) reduction in the 5.3–8.7 GHz band. This design also has polarization insensitivity and angular stability.

Ultralight N-doped platanus acerifolia biomass carbon microtubes/RGO composite aerogel with enhanced mechanical properties and high-performance microwave absorption

Biomass-derived carbon material, an ideal lightweight and sustainable electromagnetic wave (EMW) absorption material, has adjustable dielectric properties, which is one of its greatest advantages. However, how to comprehensively control its composite dielectric constant to achieve strong microwave absorption (MA), wide effective absorption bandwidth (EAB), light mass, and thin thickness is still challenging. In this study, the N-doped biomass carbon microtubes/RGO composite aerogel (N-BCMT/RGO) with a three-dimensional multistage pore network structure was prepared by using the waste Platanus acerifolia tree fruit-derived biomass microtubes as the base, through heteroatom doping and composite conductive material. Among them, the doping of nitrogen atoms introduces numerous defects and promotes the formation of a heterogeneous interface, which plays an important role in regulating conduction and polarization loss. Secondly, the introduction of conductive material effectively promotes the hopping and migration of electrons, which further enhances the conduction loss. Moreover, the close binding of BCMT and RGO causes N-BCMT/RGO aerogel to exhibit enhanced mechanical properties. The special multistage hole structure allows N-BCMT/RGO to exhibit good impedance matching and ultra-low density (0.0121 g/cm3), which also exhibits an ultra-wide EAB of 8.36 GHz and a minimum reflection loss (RLmin) of −55.45 dB at an ultra-low filler loading of 2 wt%. This opens up an avenue for the realization of novel microwave absorbers with light weight and high performance, and the proposed comprehensive control strategy for the composite permittivity of biomass-carbon materials provides new ideas for activating the MA behavior of metal-free carbon-based absorbers.

Natural magnetite/coke composite: A novel promising microwave absorption material

Fe3O4 and carbon materials are the two most common materials in research on microwave-absorbing materials. However, in previous studies, the material sources of Fe3O4 and carbon materials mostly came from the addition of chemical reagents, which meant that expensive raw materials and complex preparation processes restrict the large-scale production and application of microwave-absorbing materials from the raw material level. The preparation of highly efficient electromagnetic wave-absorbing materials from natural mineral resources may be the key way to solve this problem. In this work, pure magnetite minerals and original coking coal were used as the sources of Fe3O4 and carbon materials in the composite material. Through the combination of mixed ball milling and high-temperature roasting, the two natural mineral materials were successfully combined to prepare a magnetite/coke composite material with a porous network structure (Ma/Coke). After carbonization, a continuous network was formed to effectively coat or load magnetic magnetite particles, which formed the electromagnetic cooperative loss mechanism. By optimizing the material ratio, the microstructure of the composite was effectively regulated, and the impedance matching of the material was improved, showing excellent electromagnetic wave-absorbing performance. Ma/Coke-0.5 had a minimum reflection loss (RLmin) of − 57.86 dB and an effective absorption bandwidth of up to 5.47 GHz. This work provides a low-cost, high-efficiency, environment-protecting, and large-scale preparation method for electromagnetic wave-absorbing materials based on natural minerals and provides a new feasible suggestion for the functional application of natural mineral materials.

Phthalocyanine-mediated interfacial self-assembly of magnetic graphene nanocomposites toward low-frequency electromagnetic wave absorption

Exploring multi-component composite is promising for advanced electromagnetic wave (EMW) absorption materials, yet challenged by balancing low-frequency absorption and cost-effective preparation mode. Herein, a series of dielectric-magnetic nanocomposites are fabricated as EMW absorbers via facile phthalocyanine-mediated interfacial self-assembly approach. Phthalocyanine could act as a functional reagent to modify magnetic Fe3O4 nanosphere and guarantee the self-assembly with reduced graphene oxide nanosheet simultaneously. Owing to the flexible self-assembly, the as-synthesized ternary nanocomposite exhibits highly tunable EMW absorption performance toward low-frequency absorption. The minimum reflection loss reaches −49.0 dB (99.998 % wave absorption) simultaneously at a low frequency of 5.4 GHz and a high frequency of 8.3 GHz, which displays superb absorption efficiency in both the C band and X band. The phthalocyanine-mediated dielectric-magnetic synergy endows the nanocomposite with enhanced impedance matching and multiple dissipation pathways. This study demonstrates a convenient strategy for the rational design of low-frequency EMW absorbers with high-efficiency absorption.

Structurally Stable, High-Strength Graphene Oxide/Carbon Nanotube/Epoxy Resin Aerogels as Three-Dimensional Skeletal Precursors for Wave-Absorbing Materials.

Three-dimensional (3D) graphene oxide aerogel (GOA) is one of the best fillers for composites for microwave absorption. However, its further development has been hindered by the poor mechanical properties. Methodology to improve the mechanical properties of the aerogel remains an urgent challenge. Herein, graphene oxide/carbon nanotube/epoxy resin composite aerogel (GCEA) was successfully prepared by a facile method. The results showed that the prepared GCEA with the hierarchical and 3D cross-linked structures exhibited excellent compression performance, structural and thermal stability, high hydrophilicity, and microwave absorption. The prepared GCEA recovered from multiple large strain cycles without significant permanent deformation. The minimum reflection loss (RL) was −39.60 dB and the maximum effective absorption bandwidth (EAB) was 2.48 GHz. The development of the enhanced GO aerogels will offer a new approach to the preparation of 3D microwave-absorbing skeletal materials with good mechanical properties.

Flower-like CoLa/Ti3C2Tx nanocomposites for high-performance electromagnetic wave absorption

A novel flower-like CoLa spheres decorated Ti3C2Tx MXene nanocomposite (CoLa/Ti3C2Tx) has been prepared by co-solvothermal method. The as-prepared material exhibits excellent electromagnetic wave absorption performance by controlling the mass ratio of Co2+ and La3+. The minimum reflection loss value (RLmin) of CoLa/Ti3C2Tx-17:2 (the mass ratio of Co2+ to La3+ is 17:2) is − 59.14 dB with the thickness of 1.1 mm at 17.11 GHz. The effective absorption bandwidth (EAB, RL<−10 dB) covers 14–18 GHz (4 GHz in total) under 1.2 mm. The excellent performance of CoLa/Ti3C2Tx-17:2 can be attributed to the suitable impedance matching and the synergistic effect of multiple loss mechanism, including interface polarization, dipolar polarization, multiple reflections, natural resonance and exchange resonance. Therefore, the flower-like CoLa/Ti3C2Tx nanocomposite is expected to be a promising electromagnetic wave absorption material.