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High‐efficiency and sustainable membrane purification technology is highly desirable but unattainable in the field of water treatment. 2D materials are emerging as very promising candidates for water treatment applications. However, membranes assembled by pure 2D materials lack reasonable structural and functional design, usually exhibiting relatively low water permeance, purification performance, and fouling resistance. Here, a mixed‐dimensional membrane is designed to solve the above‐mentioned problems by assembling two kinds of in situ grown 0D@2D functional building blocks of SiO2@GO and TiO2@MXene. Specifically, the obtained membrane exhibits high and maintainable water permeance of 2114 L m−2 h−1 bar−1 as well as high rejection rates toward organic dyes thanks to the plentiful firm water channels constructed by 0D@2D structures and the negative charges on both SiO2@GO and TiO2@MXene, respectively. Moreover, the 0D@2D TiO2@MXene serves as photocatalyst, rendering the composite membrane intriguing self‐cleaning function under UV irradiation, which is verified by the high recovery ratios of water permeance (97.5%) and dye interception rate (98.7%). Thus, this work offers a promising approach for the design of highly efficient and sustainable membrane for separation and purification purposes. [ABSTRACT FROM AUTHOR]

Developing microwave absorbers with superior low-frequency electromagnetic wave absorption properties is one of the foremost important factors driving the boom in 5G technology development. In this study, via a simple hydrothermal and pyrolysis strategy, randomly interleaved CoNiO2 nanosheets and uniformly ultrafine CoNi nanocrystals are anchored onto both sides of a single-layered MXene. The absorption mechanism demonstrated that the hierarchical heterostructure prevents the aggregation of MXene nanoflakes and magnetic crystallites. In addition, the introduction of the double-magnetic phase of CoNiO2/CoNi arrays can not only enhance the magnetic loss capacity but also generate larger void spaces and abundant heterogeneous interfaces, collectively promoting impedance-matching and furthering microwave attenuation capabilities at a low frequency. Hence, the reflection loss of the optimal absorber (M–MCNO) is −45.33 dB at 3.24 GHz, which corresponds to a matching thickness of 5.0 mm. Moreover, its EAB can entirely cover the S-band and C-band by tailoring the matching thickness from 2 to 7 mm. Satellite radar cross-section (RCS) simulations demonstrated that the M–MCNO can reduce the RCS value to below −10 dB m2 over a multi-angle range. Thus, the proposed hybrid absorber is of great significance for the development of magnetized MXene composites with superior low-frequency microwave absorption properties. [ABSTRACT FROM AUTHOR]

Millimeter wave antennas have the advantage of high directivity, miniaturization, high resolution and data transfer speed, wide bandwidth, and lower latency. In this work, a millimeter wave planar array antenna (PAA) with the characteristics of wideband and low sidelobes, which consists of eight identical linear array antenna (LAA) based on Ti3C2 MXene, is designed and fabricated. It is the first time that MXene antennas are proposed for a 5G millimeter wave antenna application. MXene PAA has a high realized gain of 22.22 dBi and a −10 dB impedance bandwidth of measurement covering the range from 24 GHz to 28 GHz, including the 5G FR2—n258 frequency band. With Chebyshev current distribution, the MXene PAA has a half-power beam width of 10.2° and 10.8° in the xoz-plane and yoz-plane radiation patterns with the sidelobes levels below −20 dB, respectively. Therefore, MXene PAA is suitable for 5G mobile communication applications. [ABSTRACT FROM AUTHOR]

As a recently emerging 2D material, Ti3C2TX MXene, with some distinct characters, might bring opportunities for developing advanced microwave absorption materials (MAMs). Although the multilayered MXene with an accordion-like structure has been used as the building blocks to obtain composite MAMs, the exfoliated MXene (eMXene) nanosheets have rarely been explored. Herein, we construct a hierarchically structured MXene-based composite by simultaneously decorating magnetic nanosheets/particles onto eMXene sheets for an efficient microwave absorption. Systematic ex situ characterizations reveal that the eMXene sheets can act as a structure-directing agent and host to allow an interlaced growth of ultrathin CoO nanosheets and spherical Co@C nanoparticles onto their surfaces. Such structural design impedes the agglomeration of eMXene sheets and magnetic nanounits while guaranteeing the adequate exposure of polar functional groups on MXene surfaces. Meanwhile, the introduction of dual magnetic phases enables an additional magnetic loss capability and also builds massive void spaces and rich heterointerfaces between various nanounits for a significantly enhanced dielectric polarization loss, resulting in a superior impedance matching and attenuation capability. Accordingly, the optimal composite exhibits a minimum reflection loss of −73.4 dB at a thin thickness of 2.1 mm and an effective absorption bandwidth up to 5.6 GHz (12.4–18.0 GHz) at a thin thickness of 1.8 mm. This study might stimulate the further development of exfoliated MXene-based composite microwave absorbers with hierarchical structures. [ABSTRACT FROM AUTHOR]

MXene-based films have garnered significant attention for their remarkable electrical and mechanical properties. Nevertheless, the practical application of MXene is impeded by its intrinsic instability caused by spontaneous oxidation. The traditional anti-oxidative strategies frequently lead to a compromise in stability, electrical conductivity, and mechanical properties. In this study, a novel approach is proposed involving metal nano-armoring, wherein a copper layer with nano thickness is deposited onto MXene film surfaces to establish a uniform and seamless heterogeneous interface (MXene@Cu). The precise tunability and uniformity of this heterostructure are consistently demonstrated through both theoretical calculations and experimental results. The MXene@Cu films exhibit exceptional electrical conductivity of 1.17 × 10 6 S m -1 , electromagnetic interference shielding effectiveness of 77.1 dB, and tensile strength of 43.4 MPa. More importantly, this heterostructure significantly improves MXene's stability against oxidation. After exposure to air for 30 days, the resultant MXene@Cu films exhibit a remarkable conductivity retention of 72.0%, significantly exceeding that of pristine MXene films (44.3%). This scalable synthesis approach holds significant promise for electronic device applications, particularly in electromagnetic shielding and thermal management., (© 2024 Wiley‐VCH GmbH.)