Conductive Bimetal-Organic Frameworks with Volcano-Type Fine-Tuned Dielectric Properties for Electromagnetic Wave Absorption.

Inherently conductive metal-organic frameworks (cMOFs) deliver significant potential for tailoring charge transport characteristics in functional applications. Herein, we synthesize a bimetallic NiCu-HHTP cMOF with precisely controllable interlayer spacing, enabling fine-tuning of the charge transport, electronic band structure, and dielectric properties. By exploiting differences in self-polarization effects between active ions, NiCu-HHTP exhibits an inverted volcano-type interlayer spacing variation through controlled modulation of ion proportions and produces volcano-type tunable dielectric properties.

Tailored Multi-Band Microwave Absorption Performance via Entropy Engineering in Spinel Ferrite/Carbon Nanofiber Composites.

The development of electromagnetic microwave absorption (EMA) materials with broad frequency compatibility remains a great challenge, as most of the conventional materials fail to deliver effective microwave attenuation across multiple frequency bands owing to the inferior balance between dielectric and magnetic components. To address this, a novel entropy engineering strategy is presented to fabricate spinel ferrites/carbon composite nanofibers through a combined electrospinning and heat-treatment method as versatile candidates for microwave absorption. Distinct from the traditional spinel oxides, the customized atomic species in MNZCFO/C nanofibers offer superior control over electromagnetic attenuation in specific frequency bands, enabling enhanced multi-band absorption properties.

Ultralight SiO Nanofiber-Reinforced Graphene Aerogels for Multifunctional Electromagnetic Wave Absorber.

The high-efficiency utilization of two-dimensional (2D) graphene layers for developing durable multifunctional electromagnetic wave (EMW) absorbing aerogels is highly demanded yet remains challenging. Here, renewable, low-density, high-strength, and large-aspect-ratio ceramic silicon dioxide (SiO) nanofibers were efficiently prepared to assist in the preparation of ultralight yet robust, highly elastic, and hydrophobic graphene aerogels using facile, scalable freeze-drying followed by a carbonization approach. The ceramic nanofibers efficiently prevent the agglomeration of graphene and enhance interfacial interactions, significantly promoting mechanical strength.

Recent Advances in MXene-Based Aerogels for Electromagnetic Wave Absorption.

Developing lightweight, high-performance electromagnetic wave (EMW) absorbing materials those can absorb the adverse electromagnetic radiation or waves are of great significance. Transition metal carbides and/or nitrides (MXenes) are a novel type of 2D nanosheets associated with a large aspect ratio, abundant polar functional groups, adjustable conductivity, and remarkable mechanical properties. This contributes to the high-efficiency assembly of MXene-based aerogels possessing the ultra-low density, large specific surface area, tunable conductivity, and unique 3D porous microstructure, which is beneficial for promoting the EMW absorption.

NO-Sensitive SnO Nanoparticles Prepared Using a Freeze-Drying Method.

The n-type semiconductor SnO with a wide band gap (3.6 eV) is massively used in gas-sensitive materials, but pure SnO still suffers from a high operating temperature, low response, and tardy responding speed. To solve these problems, we prepared small-sized pure SnO using hydrothermal and freeze-drying methods (SnO-FD) and compared it with SnO prepared using a normal drying method (SnO-AD).

Ultralight Hierarchical FeO/MoS/rGO/TiCT MXene Composite Aerogels for High-Efficiency Electromagnetic Wave Absorption.

Aerogel-based composites, renowned for their three-dimensional (3D) network architecture, are gaining increasing attention as lightweight electromagnetic (EM) wave absorbers. However, attaining high reflection loss, broad effective absorption bandwidth (EAB), and ultrathin thickness concurrently presents a formidable challenge, owing to the stringent demands for precise structural regulation and incorporation of magnetic/dielectric multicomponents with synergistic loss mechanisms within the 3D networks. In this study, we successfully synthesized a 3D hierarchical porous FeO/MoS/rGO/TiCT MXene (FMGM) composite aerogel via directional freezing and subsequent heat treatment processes.

Ruthenium-Cobalt Solid-Solution Alloy Nanoparticles for Enhanced Photopromoted Thermocatalytic CO Hydrogenation to Methane.

Bimetallic alloy nanoparticles have garnered substantial attention for diverse catalytic applications owing to their abundant active sites and tunable electronic structures, whereas the synthesis of ultrafine alloy nanoparticles with atomic-level homogeneity for bulk-state immiscible couples remains a formidable challenge. Herein, we present the synthesis of RuCo solid-solution alloy nanoparticles (ca. 2 nm) across the entire composition range, for highly efficient, durable, and selective CO hydrogenation to CH under mild conditions.

Enhancing Interface Connectivity for Multifunctional Magnetic Carbon Aerogels: An In Situ Growth Strategy of Metal-Organic Frameworks on Cellulose Nanofibrils.

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.

Metal-organic frameworks with fine-tuned interlayer spacing for microwave absorption.

Designing a functional, conductive metal-organic framework (cMOF) is highly desired. Substantial efforts have been dedicated to increasing the intralayer conjugation of the cMOFs, while less dedication has been made to tuning the interlayer charge transport of the metal-organic nanosheets for the controllable dielectric property. Here, we construct a series of conductive bimetallic organic frameworks of (ZnCu) (hexahydroxytriphenylene) (ZnCu-HHTP) to allow for fine-tuned interlayer spacing of two-dimensional frameworks, by adjusting the ratios of Zn and Cu metal ions.

Reinforcing the Efficiency of Photothermal Catalytic CO Methanation through Integration of Ru Nanoparticles with Photothermal MnCoO Nanosheets.

Carbon dioxide (CO) hydrogenation to methane (CH) is regarded as a promising approach for CO utilization, whereas achieving desirable conversion efficiency under mild conditions remains a significant challenge. Herein, we have identified ultrasmall Ru nanoparticles (∼2.5 nm) anchored on MnCoO nanosheets as prospective photothermal catalysts for CO methanation at ambient pressure with light irradiation.

Nitrogen-Doped Magnetic-Dielectric-Carbon Aerogel for High-Efficiency Electromagnetic Wave Absorption.

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.

Diverse Structural Design Strategies of MXene-Based Macrostructure for High-Performance Electromagnetic Interference Shielding.

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.

Bioinspired Hollow/Hollow Architecture with Flourishing Dielectric Properties for Efficient Electromagnetic Energy Reclamation Device.

The exploitation of advanced electromagnetic functional devices is perceived as the effective prescription to deal with environmental contamination and energy deficiency. From the perspective of observing and imitating nature, pine branch-like zirconium dioxide/cobalt nanotubes@nitrogen-doped carbon nanotubes are synthesized victoriously through maneuverable electrospinning process and follow-up thermal treatments. In particular, introducing carbon nanotubes on the surface of hollow nanofibers to construct hierarchical architecture vastly promoted the material's dielectric properties by significantly augmenting specific surface area, generating abundant heterogeneous interfaces, and inducing the formation of defects.

A review on composite strategy of MOF derivatives for improving electromagnetic wave absorption.

To address the electromagnetic wave (EMW) pollution issues caused by the development of electronics and wireless communication technology, it is urgent to develop efficient EMW-absorbing materials. With controllable composition, diverse structure, high porosity, and large specific surface area, metal-organic framework (MOF) derivatives have sparked the infinite passion and creativity of researchers in the electromagnetic field. Against the challenges of poor inherent impedance matching and insufficient attenuation capability of pure MOF derivative, designing and developing MOF derivative-based composites by compounding MOF with other materials, such as graphene, CNTs, MXene, and so on, has been an effective strategy for constructing high-efficiency EMW absorbing materials.

Conductive Metal-Organic Frameworks with Tunable Dielectric Properties for Boosting Electromagnetic Wave Absorption.

Metal-organic frameworks (MOFs) manifest enormous potential in promoting electromagnetic wave (EMW) absorption thanks to the tailored components, topological structure, and high porosity. Herein, rodlike conductive MOFs (cMOFs) composed of adjustable metal ions of Zn, Cu, Co, or Ni and ligands of hexahydroxytriphenylene (HHTP) are prepared to attain tunable dielectric properties for a tailored EMW absorption. Specifically, the influences of the cMOFs' composition, charge transport characteristic, topological crystalline structure, and anisotropy microstructure on dielectric and EMW absorption performance are ascertained, advancing the understanding of EMW attenuation mechanisms of MOFs.

In-Situ Fabrication of Sustainable-N-Doped-Carbon-Nanotube-Encapsulated CoNi Heterogenous Nanocomposites for High-Efficiency Electromagnetic Wave Absorption.

Developing carbon encapsulated magnetic composites with rational design of microstructure for achieving high-performance electromagnetic wave (EMW) absorption in a facile, sustainable, and energy-efficiency approach is highly demanded yet remains challenging. Here, a type of N-doped carbon nanotube (CNT) encapsulated CoNi alloy nanocomposites with diverse heterostructures are synthesized via the facile, sustainable autocatalytic pyrolysis of porous CoNi-layered double hydroxide/melamine. Specifically, the formation mechanism of the encapsulated structure and the effects of heterogenous microstructure and composition on the EMW absorption performance are ascertained.

Highly Efficient NO Sensors Based on Al-ZnOHF under UV Assistance.

Zinc hydroxyfluoride (ZnOHF) is a newly found resistive semiconductor used as a gas-sensing material with excellent selectivity to NO because of its unique energy band structure. In this paper, Al doping and UV radiation were used to further improve the gas-sensing performance of ZnOHF. The optimized 0.

Large-Scale Synthesis of Multifunctional Single-Phase Co C Nanomaterials.

Achieving scalable synthesis of nanoscale transition-metal carbides (TMCs), regarded as substitutes for platinum-group noble metals, remains an ongoing challenge. Herein, a 100-g scale synthesis of single-phased cobalt carbide (Co C) through carburization of Co-based Prussian Blue Analog (Co-PBA) is reported in CO /H atmosphere under mild conditions (230 °C, ambient pressure). Textural property investigations indicate a successful preparation of orthorhombic-phased Co C nanomaterials with Pt-group-like electronic properties.

Ir-CoO Active Centers Supported on Porous Al O Nanosheets as Efficient and Durable Photo-Thermal Catalysts for CO Conversion.

Photo-thermal catalytic CO hydrogenation is currently extensively studied as one of the most promising approaches for the conversion of CO into value-added chemicals under mild conditions; however, achieving desirable conversion efficiency and target product selectivity remains challenging. Herein, the fabrication of Ir-CoO/Al O catalysts derived from Ir/CoAl LDH composites is reported for photo-thermal CO methanation, which consist of Ir-CoO ensembles as active centers that are evenly anchored on amorphous Al O nanosheets. A CH production rate of 128.

Transition metal elements-doped SnO for ultrasensitive and rapid ppb-level formaldehyde sensing.

Pristine SnO, Fe-doped SnO and Ni-doped SnO were synthesized using facile hydrothermal method. Analysis based on XRD, TEM and UV-Vis DRS measurements demonstrated the successful insertion of Fe and Ni dopants into SnO crystal. Formaldehyde-detection measurements revealed that transition metal-doped SnO exhibited improved formaldehyde-sensing properties compared with that of pristine SnO.

Imbedding Pd Nanoparticles into Porous InO Structure for Enhanced Low-Concentration Methane Sensing.

Methane (CH), as the main component of natural gas and coal mine gas, is widely used in daily life and industrial processes and its leakage always causes undesirable misadventures. Thus, the rapid detection of low concentration methane is quite necessary. However, due to its robust chemical stability resulting from the strong tetrahedral-symmetry structure, the methane molecules are usually chemically inert to the sensing layers in detectors, making the rapid and efficient alert a big challenge.

Heterogeneous CuS/C nanocomposite fibers with adjustable electromagnetic parameters for efficient electromagnetic absorption.

One-dimensional carbon-based materials have emerged as promising electromagnetic wave absorption agents due to their outstanding conductivity, high stability, low weight, and easy availability. Properly optimizing their electromagnetic parameters is expected to further enhance the electromagnetic wave attenuation capacity. In this work, efficient CuS/C nanocomposite fibers are prepared by a combined approach of electrospinning and subsequent carbonization-sulfurization processes.

From MXene Trash to Ultraflexible Composites for Multifunctional Electromagnetic Interference Shielding.

The development of flexible composites based on the transition metal carbides/nitrides (MXenes) is gaining popularity because of MXenes' high application potentials for electromagnetic interference (EMI) shields. Here, we prepare a new type of ultraflexible composite films composed of "trashed" MXene sediment (MS) and waterborne polyurethane using a simple, facile solution casting approach. In addition to the outstanding mechanical strength and electrical conductivity, an extremely wide-range of MS contents can be achieved for the composites, resulting in EMI shielding effectiveness (SE) that may be controlled over a wide range.

Ultrathin Cellulose Nanofiber Assisted Ambient-Pressure-Dried, Ultralight, Mechanically Robust, Multifunctional MXene Aerogels.

Ambient-pressure-dried (APD) preparation of transition metal carbide/nitrides (MXene) aerogels is highly desirable yet remains highly challenging. Here, ultrathin, high-strength-to-weight-ratio, renewable cellulose nanofibers (CNFs) are efficiently utilized to assist in the APD preparation of ultralight yet robust, highly conductive, large-area MXene-based aerogels via a facile, energy-efficient, eco-friendly, and scalable freezing-exchanging-drying approach. The strong interactions of large-aspect-ratio CNF and MXene as well as the biomimetic nacre-like microstructure induce high mechanical strength and stability to avoid the structure collapse of aerogels in the APD process.

Bicontinuous, High-Strength, and Multifunctional Chemical-Cross-Linked MXene/Superaligned Carbon Nanotube Film.

Lightweight, thin, large-area, and ultraflexible chemical-cross-linked MXene/superaligned carbon nanotube composite films with a bicontinuous structure are manufactured. The films exhibit high mechanical strength, good electrical conductivity, hydrophobicity, and oxidation stability, as well as wearable multifunctionalities involving electromagnetic interference (EMI) shielding, electrothermal conversion, and photothermal antibacterial performance. An X-band EMI shielding effectiveness (SE) of 24 to 70 dB at the thickness of 8 to 28 μm and an SE of more than 60 dB in ultrabroadband frequency range of 8.