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HighlightsIn terms of components and structures, this review summarizes progresses and highlights strategies of MOF derivatives for efficient electromagnetic wave absorption.We also systematically delineate relevant theories and points out the prospects and current challenges.To tackle the aggravating electromagnetic wave (EMW) pollution issues, high-efficiency EMW absorption materials are urgently explored. Metal–organic framework (MOF) derivatives have been intensively investigated for EMW absorption due to the distinctive components and structures, which is expected to satisfy diverse application requirements. The extensive developments on MOF derivatives demonstrate its significantly important role in this research area. Particularly, MOF derivatives deliver huge performance superiorities in light weight, broad bandwidth, and robust loss capacity, which are attributed to the outstanding impedance matching, multiple attenuation mechanisms, and destructive interference effect. Herein, we summarized the relevant theories and evaluation methods, and categorized the state-of-the-art research progresses on MOF derivatives in EMW absorption field. In spite of lots of challenges to face, MOF derivatives have illuminated infinite potentials for further development as EMW absorption materials.

HighlightsNon-magnetic bimetallic MOF-derived porous carbon-wrapped TiO2/ZrTiO4 composites are firstly used for efficient electromagnetic wave absorption. The electromagnetic wave absorption mechanisms including enhanced interfacial polarization and essential conductivity are intensively discussed.Modern communication technologies put forward higher requirements for electromagnetic wave (EMW) absorption materials. Metal–organic framework (MOF) derivatives have been widely concerned with its diverse advantages. To break the mindset of magnetic-derivative design, and make up the shortage of monometallic non-magnetic derivatives, we first try non-magnetic bimetallic MOFs derivatives to achieve efficient EMW absorption. The porous carbon-wrapped TiO2/ZrTiO4 composites derived from PCN-415 (TiZr-MOFs) are qualified with a minimum reflection loss of − 67.8 dB (2.16 mm, 13.0 GHz), and a maximum effective absorption bandwidth of 5.9 GHz (2.70 mm). Through in-depth discussions, the synergy of enhanced interfacial polarization and other attenuation mechanisms in the composites is revealed. Therefore, this work confirms the huge potentials of non-magnetic bimetallic MOFs derivatives in EMW absorption applications.

HighlightsMXene-based macrostructure development and EMI shielding mechanisms are reviewed.Various structural design strategies for MXene-based EMI shielding materials are highlighted and discussed.Current challenges and future directions for MXenes in electromagnetic interference shielding are outlined.There is an urgent demand for flexible, lightweight, mechanically robust, excellent electromagnetic interference (EMI) shielding materials. Two-dimensional (2D) transition metal carbides/nitrides (MXenes) have been potential candidates for the construction of excellent EMI shielding materials due to their great electrical electroconductibility, favorable mechanical nature such as flexibility, large aspect ratios, and simple processability in aqueous media. The applicability of MXenes for EMI shielding has been intensively explored; thus, reviewing the relevant research is beneficial for advancing the design of high-performance MXene-based EMI shields. Herein, recent progress in MXene-based macrostructure development is reviewed, including the associated EMI shielding mechanisms. In particular, various structural design strategies for MXene-based EMI shielding materials are highlighted and explored. In the end, the difficulties and views for the future growth of MXene-based EMI shields are proposed. This review aims to drive the growth of high-performance MXene-based EMI shielding macrostructures on basis of rational structural design and the future high-efficiency utilization of MXene.

HighlightsAn ingenious design achieved magnetic-dielectric-carbon coupling.Nickel and manganese oxide particles were in situ reduced and grew on the carbon aerogels.The aerogels demonstrated radar stealth, infrared stealth and thermal management capability.Carbon-based aerogels derived from biomass chitosan are encountering a flourishing moment in electromagnetic protection on account of lightweight, controllable fabrication and versatility. Nevertheless, developing a facile construction method of component design with carbon-based aerogels for high-efficiency electromagnetic wave absorption (EWA) materials with a broad effective absorption bandwidth (EAB) and strong absorption yet hits some snags. Herein, the nitrogen-doped magnetic-dielectric-carbon aerogel was obtained via ice template method followed by carbonization treatment, homogeneous and abundant nickel (Ni) and manganese oxide (MnO) particles in situ grew on the carbon aerogels. Thanks to the optimization of impedance matching of dielectric/magnetic components to carbon aerogels, the nitrogen-doped magnetic-dielectric-carbon aerogel (Ni/MnO-CA) suggests a praiseworthy EWA performance, with an ultra-wide EAB of 7.36 GHz and a minimum reflection loss (RLmin) of − 64.09 dB, while achieving a specific reflection loss of − 253.32 dB mm−1. Furthermore, the aerogel reveals excellent radar stealth, infrared stealth, and thermal management capabilities. Hence, the high-performance, easy fabricated and multifunctional nickel/manganese oxide/carbon aerogels have broad application aspects for electromagnetic protection, electronic devices and aerospace.

Photo‐thermal catalytic CO2 hydrogenation is currently extensively studied as one of the most promising approaches for the conversion of CO2 into value‐added chemicals under mild conditions; however, achieving desirable conversion efficiency and target product selectivity remains challenging. Herein, the fabrication of Ir‐CoO/Al2O3 catalysts derived from Ir/CoAl LDH composites is reported for photo‐thermal CO2 methanation, which consist of Ir‐CoO ensembles as active centers that are evenly anchored on amorphous Al2O3 nanosheets. A CH4 production rate of 128.9 mmol gcat⁻1 h⁻1  is achieved at 250 °C under ambient pressure and visible light irradiation, outperforming most reported metal‐based catalysts. Mechanism studies based on density functional theory (DFT) calculations and numerical simulations reveal that the CoO nanoparticles function as photocatalysts to donate electrons for Ir nanoparticles and meanwhile act as “nanoheaters” to effectively elevate the local temperature around Ir active sites, thus promoting the adsorption, activation, and conversion of reactant molecules. In situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS) demonstrates that illumination also efficiently boosts the conversion of formate intermediates. The mechanism of dual functions of photothermal semiconductors as photocatalysts for electron donation and as nano‐heaters for local temperature enhancement provides new insight in the exploration for efficient photo‐thermal catalysts. This work prepares Ir‐CoO/Al2O3 catalysts to realize the highly efficient photo‐thermal catalytic CO2 methanation under mild conditions. The CoO nanoparticles function as photocatalysts to donate electrons for Ir nanoparticles and meanwhile act as “nanoheaters” to effectively elevate the local temperature around Ir active sites, thus promoting the adsorption, activation, and conversion of reactant molecules.

With the increasingly serious electromagnetic wave (EMW) pollution, the development of high-performance EMW absorbing materials (EWAMs) has become a hot topic. Carbon-based EWAMs have excellent chemical stability, high electrical conductivity, and strong dielectric loss. In particular, three-dimensional (3D) porous carbon-based EWAMs have been widely developed in the EMW absorption field. The 3D porous structure not only reduces the materials’ mass density, but also improves the multiple reflections of incident EMWs and impedance matching. The carbon-based EWAMs are thus expected to achieve the goals of low density, low thickness, wide absorption bandwidth, and strong absorption. Herein, we first restated the relevant theoretical basis and evaluation methods. Then, we summarized the recent research progress of 3D porous carbon-based EWAMs with the source of the materials as the main clue. Some unique and novel viewpoints were highlighted. Finally, the challenges and prospects of 3D porous carbon-based EWAMs were put forward, which is helpful for guiding a further development of high-performance EWAMs.

Improving interface connectivity of magnetic nanoparticles in carbon aerogels is crucial, yet challenging for assembling lightweight, elastic, high‐performance, and multifunctional carbon architectures. Here, an in situ growth strategy to achieve high dispersion of metal–organic frameworks (MOFs)‐anchored cellulose nanofibrils to enhance the interface connection quality is proposed. Followed by a facile freeze‐casting and carbonization treatment, sustainable biomimetic porous carbon aerogels with highly dispersed and closely connected MOF‐derived magnetic nano‐capsules are fabricated. Thanks to the tight interface bonding of nano‐capsule microstructure, these aerogels showcase remarkable mechanical robustness and flexibility, tunable electrical conductivity and magnetization intensity, and excellent electromagnetic wave absorption performance. Achieving a reflection loss of −70.8 dB and a broadened effective absorption bandwidth of 6.0 GHz at a filling fraction of merely 2.2 wt.%, leading to a specific reflection loss of −1450 dB mm−1, surpassing all carbon‐based aerogel absorbers so far reported. Meanwhile, the aerogel manifests high magnetic sensing sensibility and excellent thermal insulation. This work provides an extendable in situ growth strategy for synthesizing MOF‐modified cellulose nanofibril structures, thereby promoting the development of high‐value‐added multifunctional magnetic carbon aerogels for applications in electromagnetic compatibility and protection, thermal management, diversified sensing, Internet of Things devices, and aerospace. A strategy for in situ growing MOFs on cellulose nanofibrils is proposed to promote interface connectivity. Strong anchoring of MOFs produces a unique structure of nano‐capsules tightly embedded in carbon skeletons. The product CoFe/carbon aerogels exhibit exceptional specific reflection loss of −1450 dB mm−1, surpassing all reported carbon aerogels, and demonstrate application potential in thermal management and magnetic sensing.

HighlightsFabrication, characterizations and photothermal properties of MXenes are systematically described.Photothermal-derived antibacterial performances and mechanisms of MXenes-based materials are summarized and reviewed.Recent advances in the derivative applications relying on antibacterial properties of MXenes-based materials, including in vitro and in vivo sterilization, solar water evaporation and purification, and flexible antibacterial fabrics, are investigated.The pernicious bacterial proliferation and emergence of super-resistant bacteria have already posed a great threat to public health, which drives researchers to develop antibiotic-free strategies to eradicate these fierce microbes. Although enormous achievements have already been achieved, it remains an arduous challenge to realize efficient sterilization to cut off the drug resistance generation. Recently, photothermal therapy (PTT) has emerged as a promising solution to efficiently damage the integrity of pathogenic bacteria based on hyperthermia beyond their tolerance. Until now, numerous photothermal agents have been studied for antimicrobial PTT. Among them, MXenes (a type of two-dimensional transition metal carbides or nitrides) are extensively investigated as one of the most promising candidates due to their high aspect ratio, atomic-thin thickness, excellent photothermal performance, low cytotoxicity, and ultrahigh dispersibility in aqueous systems. Besides, the enormous application scenarios using their antibacterial properties can be tailored via elaborated designs of MXenes-based materials. In this review, the synthetic approaches and textural properties of MXenes have been systematically presented first, and then the photothermal properties and sterilization mechanisms using MXenes-based materials are documented. Subsequently, recent progress in diverse fields making use of the photothermal and antibacterial performances of MXenes-based materials are well summarized to reveal the potential applications of these materials for various purposes, including in vitro and in vivo sterilization, solar water evaporation and purification, and flexible antibacterial fabrics. Last but not least, the current challenges and future perspectives are discussed to provide theoretical guidance for the fabrication of efficient antimicrobial systems using MXenes.

HighlightsUltrathin, lightweight, and ultraflexible aligned single-walled carbon nanotube (SWCNT) films were fabricated via a facile, environmentally friendly, and scalable printing methodology.The aligned pattern and outstanding intrinsic properties of SWCNTs rendered “metal-like” thermal conductivity, excellent mechanical strength, hydrophobicity, and remarkable electromagnetic interference (EMI) shielding performance of the films.The excellent EMI shielding stability and reliability when subjected to mechanical deformation, chemical corrosion, and extreme environments demonstrated the significant potential of the films in aerospace, defense, and smart wearable electronics.Ultrathin, lightweight, and flexible aligned single-walled carbon nanotube (SWCNT) films are fabricated by a facile, environmentally friendly, and scalable printing methodology. The aligned pattern and outstanding intrinsic properties render “metal-like” thermal conductivity of the SWCNT films, as well as excellent mechanical strength, flexibility, and hydrophobicity. Further, the aligned cellular microstructure promotes the electromagnetic interference (EMI) shielding ability of the SWCNTs, leading to excellent shielding effectiveness (SE) of ~ 39 to 90 dB despite a density of only ~ 0.6 g cm−3 at thicknesses of merely 1.5–24 µm, respectively. An ultrahigh thickness-specific SE of 25 693 dB mm−1 and an unprecedented normalized specific SE of 428 222 dB cm2 g−1 are accomplished by the freestanding SWCNT films, significantly surpassing previously reported shielding materials. In addition to an EMI SE greater than 54 dB in an ultra-broadband frequency range of around 400 GHz, the films demonstrate excellent EMI shielding stability and reliability when subjected to mechanical deformation, chemical (acid/alkali/organic solvent) corrosion, and high-/low-temperature environments. The novel printed SWCNT films offer significant potential for practical applications in the aerospace, defense, precision components, and smart wearable electronics industries.

With the rapid advancement of terahertz technologies, electromagnetic interference (EMI) shielding materials are needed to ensure secure electromagnetic environments. Enormous efforts have been devoted to achieving highly efficient EMI shielding films by enhancing flexibility, lightweight, mechanical robustness, and high shielding efficiency. However, the consideration of the optical properties of these shielding materials is still in its infancy. By incorporating transparency, visual information from protected systems can be preserved for monitoring interior working conditions, and the optical imperceptibility allows nonoffensive and easy cover of shielding materials for both device and biology. There are many materials that can be applied to transparent EMI shields. In particular, two‐dimensional transition metal carbide/nitrides (MXenes), possessing the advantages of superior conductivity, optical properties, favorable flexibility, and facile processibility, have become a great candidate. This work reviews the recent research on developing highly efficient and optically transparent EMI shields in a comprehensive way. Materials from MXenes, indium tin oxide, metal, carbon, and conductive polymers are covered, with a focus on the employment of MXene‐based composites in transparent EMI shielding. The prospects and challenges for the future development of MXene‐based transparent EMI shields are discussed. This work aims to promote the development of high‐performance, optically transparent EMI shields for broader applications by leveraging MXenes. This work reviews the recent research on developing highly efficient and optical transparent electromagnetic interference (EMI) shields in a comprehensive way. Materials from transition metal carbide/nitrides (MXenes), indium tin oxide, metal, carbon, and conductive polymers are covered, with a focus on the employment of MXene‐based composites in transparent EMI shielding. The prospects and challenges for the future development of MXene‐based transparent EMI shields are discussed. This work aims to promote the development of high‐performance, optically transparent EMI shields for broader applications by leveraging MXenes.