Preparation of MoS<sub>2</sub>/MXene/NC Porous Composite Microspheres with Wrinkled Surface and Their Microwave Absorption Performances

Conductive carbon networks and multicomponent interfaces have been constructed in Fe 3 O 4 /TiO 2 /C or Fe 2 TiO 4 / FeTiO 3 /C composites by pyrolyzing core−shell structured Febdc@TiO 2 nanorods at different temperatures. When the temperature rises to 700 °C, the growth of internal Fe 3 O 4 nanoparticles, the gradual damage of TiO 2 shells, and the maintenance of a onedimensional structure promote the formation of continuous conductive carbon networks in paraffin, thereby increasing complex permittivity and dielectric loss. With a further increase in temperature, phase conversion from ferromagnetic Fe 3 O 4 to antiferromagnetic Fe 2 TiO 4 and FeTiO 3 would result in the depletion of TiO 2 and C, generation of multiple interfaces, and collapse of the one-dimensional structure, causing a slight reduction in complex permittivity and dielectric loss. S-700 has a wide effective absorption bandwidth (EAB) of 6.84 GHz at 2.2 mm (covering the entire Ku band), and S-800 has a large EAB of 4.16 GHz at 2.8 mm, covering the entire X band. We can deduce that conductive carbon networks mainly composed of surface carbon and multiple interfaces between carbon and titanates with defects contribute significantly to conduction loss, dipole polarization, and interfacial polarization, both of which shape RL curves under the influence of interference cancellation. This work provides a feasible strategy based on the construction of conductive networks and multicomponent interfaces in metal−organic framework-derived carbon composites for broadened microwave absorption bandwidth.

Section: Results and Discussionmentioning

confidence: 99%

Nanorod-Derived Conductive Carbon Networks and Titanates-Involved Multicomponent Interfaces for Broadband Microwave Absorption

Liu,

Cao,

Duan

et al. 2024

“…If the microstructure of MoS 2 could be modified or constructed in the actual application environment of two-dimensional materials, and the structure–activity relationship of defects or interfaces could be introduced through qualitative characterization and analysis, the dielectric microwave absorption mechanism of MoS 2 could be effectively explored, and the application prospect of low-dimensional transition metal sulfides in the field of microwave absorption could finally be expanded. In addition, the microwave absorption of single MoS 2 is poor, so researchers are devoted to studying composite materials of MoS 2 . − Whether it is composited with dielectric materials or magnetic materials, the microwave absorption performance could be improved. − The schematic illustrations of some representative MoS 2 -based microwave absorption composites are shown in Figures b and c.…”

Section: Introductionmentioning

confidence: 99%

MoS₂-Based Nanocomposites for Microwave Absorption: A Review

Li,

et al. 2024

Molybdenum disulfide (MoS2), as a two-dimensional material, has a potential application prospect in microwave absorption, electromagnetic shielding, energy storage, electrochemistry, and other fields due to its unique structure, excellent electrical conductivity, abundant surface area, and good mechanical strength. In this paper, the microwave absorbing properties of MoS2-based composites are reviewed objectively, and the recent research achievements and progress in dielectric loss type and magnetic loss type composites are summarized. Then, the microwave absorption mechanism of MoS2-based composites is systematically analyzed in terms of dielectric loss and magnetic loss. At the same time, the application of MoS2-based microwave absorbing materials in current social needs is summarized including military radar stealth and civil electronic communication. In addition, the challenges and bottlenecks in the future development of microwave absorber materials are also presented.

“…Two-dimensional materials like graphene, MoS 2 , and WSe 2 have increasingly gained prominence in the field of EMW absorption owing to their low density, huge specific surface area, and superior flexibility. Among these, MXene, an emerging two-dimensional conductive material, stands out for its stable spatial structures and numerous surface functional groups, offering significant advantages for absorption .…”

Section: Introductionmentioning

confidence: 99%

Polymorphic Polypyrrole-Modified MXene Nanosheets for Broadband Microwave Absorption

Shen,

Wang,

Huang

et al. 2024

The absorption of microwaves is significantly influenced by the structure of the absorber. Typically, the electromagnetic parameters can be adjusted by modifying the structure of the absorber. In this work, a novel approach is proposed to enhance microwave absorption properties by adjusting the impedance matching of MXene nanosheets. MXene/PPy hybrids with loose lamellar structure are synthesized through self-assembly of positively charged polypyrrole (PPy) and MXene nanosheets with negative charges, facilitated by electrostatic and hydrogen-bonding interactions. The impact of polymorphic PPy on the electromagnetic parameters and microwave absorption properties of MXene nanosheets is comprehensively explored. It is found that the addition of PPy with different morphologies can effectively tune the electromagnetic parameters of the MXene nanosheets. Particularly, the microwave absorption capabilities are significantly enhanced when PPy nanopaperclips are uniformly adsorbed on the surface of the MXene nanosheets. This enhancement is attributed to the favorable impedance match between PPy nanopaperclips and MXene nanosheets along with the exceptional attenuation capabilities of PPy. A minimum reflection loss (RLmin) of −47.85 dB is achieved at an ultrathin matched thickness of 1.6 mm, and the maximum effective absorption bandwidth (EABmax) is 5.01 GHz at 1.9 mm for the prepared MXene/PPy nanopaperclip hybrid with a filling rate of 20%. Furthermore, a bandwidth with 99% absorption efficiency of 15.4 GHz (2.4–18.0 GHz) can be attained when the thickness of the absorber ranges from 1.6 to 10.0 mm. It is anticipated that this work will provide valuable insights for the manufacture of high-performance microwave absorbers.