The rapid escalation of electromagnetic (EM) wave pollution and secondary radiation underscored the urgent need for electromagnetic interference (EMI) shielding materials with reduced reflectivity. Previous research predominantly emphasized the incorporation of magnetic fillers, often neglecting their synergistic integration with spatial architecture, thereby constraining the multifunctionality of EMI shielding systems. In contrast, layer-by-layer (LBL) fabrication technology offered precise control over microstructures and enabled multifunctional integration, which had been effectively applied in areas such as supercapacitors, controlled drug release, nanofiltration membranes and EMI shielding. By constructing tailored layered configurations, this approach facilitated tunable attenuation of electromagnetic waves. Herein, aramid nanofibers (ANF), carbon nanotubes (CNT), MXene and cobalt ferrite (CoFe2O4) were employed to fabricate a multilayer film featuring a magnetic-electric bi-continuous gradient structure via LBL assembly. Owing to its hierarchical architecture, the (Z(1)-Z(2)-Z(3))CoFe2O4@CNT/ANF-PMXene-CNT/ANF ((Z(1)-Z(2)-Z(3))CoC/A-PM-C/A) films demonstrated exceptional EMI shielding performance. Particularly, the (80-40-10)CoC/A-PM-C/A composite film achieved a high EMI shielding effectiveness (EMI SE) of 63.6 dB and exhibited a low reflection coefficient (R) of 0.613, while maintaining favorable mechanical properties, including a tensile strength of 51.2 MPa and toughness of 5.67 MJ m(-3). Simultaneously, the films exhibited superior thermal camouflage capability with a mid-infrared (IR) emissivity as low as 2.61% in the 7 similar to 17 mu m range, and displayed effective Joule-heating characteristics. This work introduced a novel strategy for the development of advanced EMI shielding materials, and the resulting (Z(1)-Z(2)-Z(3))CoC/A-PM-C/A films demonstrated considerable promise in applications involving EMI suppression, infrared stealth, and electrothermal conversion.

Developing novel transition metal carbides/nitrides (MXene)-based electromagnetic interference (EMI) shielding composites with excellent mechanical properties and oxidation resistance is urgently demanded but remains hugely challenging thanks to the increasingly sophisticated application scenarios. Herein, we demonstrated an interfacial engineering and sequential assembling strategy to synergistically address the above problems. Carbon nanotubes (CNT) were utilized to assist the splitting preparation of aramid nanofibers (ANF) and chemical crosslinking to construct a substrate layer that served to provide mechanical properties. Polydopamine (PDA) was modified onto MXene surface (PMXene) by in situ polymerization and binding, generating an adhesive layer to prevent oxygen penetration effectively. The resultant Janus-structured PMXene-CNT/ANF films exhibited outstanding mechanical performances including high tensile strength (366.8 MPa) and toughness (69.3 MJ m- 3), superb electrical conductivity (3548.8 S cm- 1), impressive EMI shielding effectiveness (EMI SE 55.5 dB) and EMI SE/t (14128.2 dB cm- 1), as well as excellent oxidation stability. Furthermore, the flexible films displayed distinguished Joule-heating performances and fast and sensitive temperature response at external voltage. Therefore, such composite films with excellent mechanical properties and environmental stability have great practical value in flexible electronics and military electronic equipment for EMI shielding, and the polarexploration equipment for anti-icing and de-icing.

This study aims to explore two-dimensional semiconductor materials with superior carrier transport properties to meet the growing demands of high-speed electronics and optoelectronic devices, focusing on evaluating the feasibility of monolayer FeGa2S4 as a candidate material through systematic theoretical investigations. First-principles calculations are used to analyze the exfoliation energy of FeGa2S4 bulk crystal, as well as the structural stability, mechanical properties, and strain-dependent optoelectronic behavior of its monolayer counterpart. Strain engineering strategies, including uniaxial and biaxial strain, are used to assess carrier mobility modulation and spectral response. Our calculation results indicate that monolayer FeGa2S4 is an indirect bandgap semiconductor (Eg = 1.65 eV) with low stiffness (Young’s modulus up to 151.6 GPa) and high flexibility (Poisson’s ratio less than 0.25), demonstrating exceptional thermodynamic stability. Under +5% uniaxial tensile strain, its electron mobilities along x and y directions dramatically increases to 5402.4 cm2·V–1·s–1 and 4164.0 cm2·V–1·s–1, fivefold higher than its hole mobility. Biaxial strain outperforms uniaxial strain in bandgap modulation and induces a systematic redshift in optical spectra, significantly enhancing visible-light harvesting efficiency. This work reveals that monolayer FeGa2S4 is a promising high-mobility photoactive material for next-generation solar cells and optoelectronics. The strain-mediated control of electronic and optical properties provides a theoretical framework for optimizing 2D semiconductors and critical guidance for experimental synthesis and device engineering. These findings highlight the potential of materials in advancing energy conversion technology and photonic applications.

Moisture-driven energy generators (MEGs) represent a renewable energy technology, yet challenges such as environmental humidity dependence and transient power generation behavior hinder their practical applications. Herein, a high-performance bilayer MEG is developed by integrating MXene-impregnated paper with a polyacrylamide (PAM) hydrogel to realize environmental tolerance and sustained power generation. Electronegative MXene and paper with 3D porous structure synergistically facilitate selective transport of positive charge, while the hydrogel serves as a water reservoir to provide a moist environment and migratory ions. The MXene-impregnated paper-hydrogel MEG (MPH-MEG) delivers a maximum open-circuit voltage (Voc) of 0.537 V and power density of 4.8 μW cm-2 at 40 % relative humidity (RH). Moreover, by replacing water in the hydrogel with sodium lactate, the MXene-impregnated paper-organic hydrogel MEG (MPO-MEG) exhibits enhanced water retention, showing a stable Voc of ∼350 mV for over 7 days, even at 40 % relative humidity (RH). Furthermore, the scalable integration of MPO-MEG units demonstrates practical application for powering commercial timers and LEDs. This work presents a novel and facile strategy for preparing high-performance and environmentally stable MEGs for sustained power generation without the need for an additional humid environment.

Thermal signatures represent ubiquitous infrared appearances of objects, carrying their unique spectral fingerprints. Despite extensive efforts to decipher and manipulate thermal-infrared signals, the ability to fully control them across spatial, temporal and spectral domains remains a significant challenge due to the slow speed, diffuse and broadband emitting nature of thermal emission in most materials. Here, we demonstrate a reconfigurable ultrafast thermal metamaterial pixel array that integrates active metasurfaces with dual-gate graphene transistors (Gr-FETs). The Gr-FETs with dual-gate control in each pixel achieve the heater-switch dual functionalities. As broadband transparent microheaters, Gr-FETs support the arbitrary design of integrated metasurfaces to achieve multi-color, narrowband infrared emission and operate at ultrafast modulation speeds. Concurrently as electrical switches, they enable a unified control scheme for pixel arrays of various sizes over large areas without compromising emission intensity. By decoupling the thermal generation and emission design processes, our approach provides an unprecedented degree of flexibility in programming thermal output across space, time, and wavelength. Our fabricated thermal pixel array experimentally demonstrated 26 alphabetical letters by applying progressive scanning, thus paving the way for practical realization of universal thermal signature controls for advanced thermal-infrared applications.

The intelligent electronic devices have urgent demands for electromagnetic interference (EMI) shielding films with excellent heat dissipation capability. However, it is challenging to obtain excellent EMI shielding and thermal conductivity performances simultaneously. Herein, inspired by mille-feuille structure, the multifunctional EMI shielding films developed by a layer-by-layer self-assembly and hot-pressing strategy. The ingenious introduction of silver nanoparticles (AgNPs) with large specific surface area and highly conductive into the network formed by TEMPO-oxidized cellulose nanofibrils (TOCNFs) with large aspect ratio to form the TOCNFs/AgNPs. And the graphene nanoplates (GNPs) with high conductivity loss distributed alternately with TOCNFs/AgNPs to construct mille-feuille structure, which had highly efficient conductive network, complete thermally conduction pathway and rich heterogeneous interfaces. Consequently, the designed films presented high electrical conductivity of 8520 S/cm, superb EMI effectiveness (SE) of 98.05 dB, and excellent thermal conductivity of 18.82 W/(m·K). Furthermore, the films possessed outstanding Joule heating performances with low voltages, including high heating temperature (100 °C), fast response time (< 20 s), and impressive heating stability and reliability. Thus, such high-performance EMI shielding films with fascinating thermal conductivity and Joule heating performances have substantial application in flexible electronics, electromagnetic waves shielding and thermal management.

MXene-based nanocomposites are highly desirable for electromagnetic interference (EMI) shielding applications. However, it is crucial but challenging to obtain an excellent trade-off between mechanical properties and EMI performances. Herein, inspired by Janus structure, flexible cellulose nanofiber-assisted MXene/silver nanowires (CNF-MXene/AgNWs) papers (CMAPs) are developed by a scalable sequential self-assembly plus a hot-pressing strategy. The ingenious introduction of highly conductive AgNWs into MXene forms a complementary leaf-like nanostructure, synergistically constructing highly effective conductive frameworks. Contributed by the designed Janus architecture, high-performance CNF substrate, and extensive hydrogen-bonding interactions, the resultant Janus CMAPs (J-CMAPs) with a low MXene/AgNWs addition of 30 wt% possess a high electrical conductivity (1066.85 S/cm), excellent mechanical strength (224.04 MPa) and modulus (9.98 GPa), exceptional EMI shielding effectiveness of 43.65 dB, and record-high EMI SE/t of 16788.51 dB cm-1 and SSE/t of 10543.18 dB cm2 g-1 with a reflection-dominant shielding mechanism, successfully achieving an outstanding balance between me-chanical properties and EMI shielding performances. More importantly, high frequency structure simulator (HFSS) simulation in the frequency domain is further conducted to intuitively comprehend the attenuation process of electromagnetic waves and shield mechanism, verifying fascinating EMI shielding performances. Besides, the Janus paper also presents desirable Joule heating performances at low input voltage, short response time (<10 s), and superb heating stability and long-term steady reliability. We believe that the J-CMAPs demonstrate the great potential and advantage for advanced EMI shielding and portable thermal management applications.

Correction for ‘Fireproof ultrastrong all-natural cellulose nanofiber/montmorillonite-supported MXene nanocomposites with electromagnetic interference shielding and thermal management multifunctional applications’ by Rui Cheng et al., J. Mater. Chem. A, 2023, 11, 18323–18335, https://doi.org/10.1039/D3TA03798C.

High-performance electrical heaters with outstanding flexibility, superior portability, and mechanical properties are highly desirable for portable thermal management. However, it is still a huge challenge to simultaneously achieve competent electrical heating performances and excellent mechanical properties. Herein, inspired by the Janus structure, versatile electrical heaters are developed via a sequential assembly followed by a hot-pressing strategy. The elaborately designed Janus structure is composed of a nanofibrillated cellulose (NFC) layer and a partially wrapped silver nanowire (AgNW) skeleton in the NFC substrate. Owing to the perfect introduction of nano-soldered points induced by thermal welding decoration, the resultant NFC/AgNW papers (NAPs) possess great flexibility, excellent mechanical strength (176.75 MPa), extremely low sheet resistance (0.60 Ω/sq), and superior electrical stabilities against mechanical deformations. Moreover, benefitting from these fascinating attributes, the NAP-based electrical heaters exhibit a remarkable heating temperature (∼220 °C), ultrafast electro-thermal response (<10 s), and groundbreaking long-term stability (∼105 °C for >186 h) and repeatability (>20,000 cycles) with low AgNW contents and driving voltages (0.5-5.0 V), which far surpass those of the previously reported and conventional indium tin oxide-based Joule heaters. Impressively, large-area production feasibilities of NAPs are demonstrated and assembled into multifunctional applications, including personal thermal management, healthcare thermotherapy, multifunctional cups, and smart homes, indicating their promising potential for wearable devices, artificial intelligence, and specific heating systems in the fields of aerospace, military, and intelligent life.

Carbon aerogels have been widely exploited for wearable piezoresistive sensing thanks to their fascinating properties such as ultralow density, high electrical conductivity, superelasticity, and fatigue resistance, but to date, maintain high mechanical performances and high sensitivity in a wide pressure range still remains a huge challenge for carbon aerogels based piezoresistive sensors. Herein, we propose a simple but efficient morphology-maintained carbonization strategy by tailoring the pyrolysis chemistry of BC to fabricate superelastic and fatigue-resistant carbon nanofiber aerogels. Bacterial cellulose hydrogels are fabricated as nanofiber aerogels with a 3D-interconnected honeycomb-like structure by unidirectional freeze-drying technology, while the rational introduction of (NH4)(2)SO4 significantly inhibits the shrinkage and deformation of bacterial cellulose nanofiber aerogels during the carbonization process, enabling the retention of the 3D-interconnected honeycomb-like structure after carbonization. The as-prepared carbon nanofiber aerogels (CNFAs) exhibit exceptional mechanical performances of high compressibility (up to 99% strain), superelasticity (-97.4%, 500 cycles at 90% compression), and fatigue resistance (up to 10 000 cycles). Moreover, the CNFAs derived sensor possesses a high sensitivity (5.66 kPa(-1)) at a wide pressure range (0-28 kPa), and a fast response time (-100 ms), enabling the CNFAs-based sensor to monitor signals of the human body, spatial pressure, and voice recognition. These fascinating attributes make the CNFAs highly attractive for flexible wearable devices.

Nanopapers derived from nanofibrillated cellulose (NFC) are urgently required as attractive substrates for thermal management applications of electronic devices because of their lightweight, easy cutting, cost efficiency, and sustainability. In this paper, we provided a facile fabrication strategy to construct hybrid nanopapers composed of dialdehyde nanofibrillated cellulose (DANFC) and silver nanoparticles (AgNPs), which exhibited a favorable thermal conductivity property. AgNPs were in situ proceeded on the surface of DANFC by the silver mirror reaction inspired by the aldehyde groups. Owing to the intermolecular hydrogen bonds inside the hybrid nanopapers, the DANFC enables the uniform dispersion of AgNPs as well as promotes the formation of the hierarchical structure. It was found that the AgNPs-coated DANFC (DANFC/Ag) hybrid nanopapers could easily form an effective thermally conductive pathway for phonon transfer. As a result, the thermal conductivity (TC) of the obtained DANFC/Ag hybrid nanopapers containing only 1.9 vol % of Ag was 5.35 times higher than that of the pure NFC nanopapers along with a significantly TC enhancement per vol % Ag of 230.0%, which was supposed to benefit from the continuous heat transfer pathway constructed by the connection of AgNPs decorated on the cellulose nanofibers. The DANFC/Ag hybrid nanopapers possess potential applications as thermal management materials in the next-generation portable electronic devices.

Wearable strain sensors have drawn growing interest in the field of intelligent electronic devices because of their inherent advantages including miniaturization and portability. For practical applications, strain sensors with lightness, flexibility, and high sensitivity are urgently desired. Herein, the interconnected silver nanowires (AgNWs) are assembled into the nanofibrillated cellulose (NFC) aerogel through unidirectional freeze-drying yielding an ultralight and conductive AgNWs/NFC aerogel (SNA) with ordered pore orientation. After thermal welding, the SNA possesses unique electron transfer channels, which can efficiently eliminate the interfacial electrical resistance at the AgNWs junctions and bring an impressive conductivity enhancement for the composite aerogel. Benefiting from the synergy of the desired microstructure and superior conductivity of as-prepared aerogel, the derived sensor shows desirable sensitivity (3.86 kPa(-1)), fast response time (180 ms), ultralow density (less than 13.58 mg/cm(3)) and detection limit of 0.5% strain, and exceptional stability and durability (over 10,000 cycles). Significantly, the integrated conductive network in SNA simultaneously offers real-time monitoring of subtle deformations and electrophysiological signals, which enables the designs of wearable device, acoustic sensor, and vehicles' speed and loading detector. The presented strategy opens up a new possibility for designing and manufacturing next-generation multifunctional strain sensor to bring the technology much closer to commercialization.

The development of biopolymer films is crucial for the replacement of conventional plastics. Tremendous effort is made to improve their performances by introducing biopolymers through the film manufacturing process. Herein, a sandwich-architectured film was proposed to efficiently improve the adhesion between the PS and PLA layers by using octenyl succinic anhydride-modified pea starch (OMPS) layer as the interlayer, leading to a highly mechanically enhanced interpenetrating network. Accordingly, the properties of the films were enhanced due to the synergism effect of sandwich architecture. In particular, the WVP value of the sandwich-architectured films (0.25 similar to 0.89 x10(-10) g.m(-1).s(-1).Pa-1) decreased more than 7-fold compared with the OMP520 film, and the OP value of the sandwich-architectured films (0.256 similar to 1.229x10(-)(12) cm(3).m.m(-2).s(-1).Pa-1) decreased more than 10-fold in comparison to the PLA film. Benefitting from the characteristics investigated above, the films exhibited a favorable effect on strawberry storage. Overall, the fabricated eco-friendly sandwich-architectured films have shown great potential for biodegradable packaging applications.

To date, various electronic devices have been strategically fabricated, and simultaneous realization of high electrical conductivity, sensing property, and heat-conducting property by a simple, efficient, and accurate approach is significant but still challenging. Here, cellulosic fiber supported 3D interconnected silver nanowire (AgNW) networks with hierarchical structures are rationally designed to achieve excellent electrical conductivity and superior thermal dispersion capability. In particular, thermal annealing at the junctions enables both phonon and electron transfer as well as impedes interfacial slippage. In the current study, the AgNW/cellulosic paper with the low Ag content (1.55 wt %) exhibits a low sheet resistance of 0.51 Omega sq(-1). More importantly, the AgNW/cellulosic paper-based flexible strain sensor has been reasonably developed, which can be applied to monitor various microstructural changes and human motions with high sensitivity and robust stability (fast response/relaxation time of similar to 100 ms and high stability >2000 bending-stretching cycles). The AgNW/cellulosic paper-based device also displays efficient thermal dispersion property, which offers exciting opportunities for thermal management application. Furthermore, the obtained hybrid paper exhibits superior heat dispersion capacity for thermal management devices. Overall, uniform dispersion and 3D interconnected junctions of AgNW among the fibers inside the cellulosic papers lead to the combination of high mechanical strength, highly efficient electrical conductivity, and ultrahigh heat dispersion property. The AgNW/cellulosic paper has promising potentials in the flexible and wearable sensing elements, thermal management materials, and artificial intelligence devices.

Superlattices consisting of alternating monolayer atomic crystals and molecular layers allow access to stable phosphorene monolayers with competitive transistor performance and to bulk monolayer materials with tunable optoelectronic properties.

Hydrazine (N2H4) reduction is one of the simplest and most widely used method for the synthesis of various metal element-based micro-/nano-materials. However, the roles of N2H4 during the chemical reaction are often diversified and subjected to further analysis. Here, Ni in turn produced its coordination compounds, hydroxide and pure metal with an increase in N2H4 content, where N2H4 plays diversified roles as a complexant, alkali resource and reductant, respectively. The elements Pr, Nd, Sm and Y exhibited high hydroxylation ability and formed their respective hydroxides. Their formation mechanisms are discussed and summarized. This study is useful for N2H4 to be employed for material synthesis. (C) 2017 Elsevier Ltd. All rights reserved.

Two-dimensional (2D) layered transition metal dichalcogenide (TMD) materials (e.g., MoS2) have attracted considerable interest due to their atomically thin geometry and semiconducting electronic properties. With ultrahigh surface to volume ratio, the electronic properties of these atomically thin semiconductors can be readily modulated by their environment. Here we report an investigation of the effects of mercury(II) (Hg2+) ions on the electrical transport properties of few-layer molybdenum disulfide (MoS2). The interaction between Hg(2+)ions and few-layer MoS2 was studied by field-effect transistor measurements and photoluminescence. Due to a high binding affinity between Hg2+ ions and the sulfur sites on the surface of MoS2 layers, Hg2+ ions can strongly bind to MoS2. We show that the binding of Hg2+ can produce a p-type doping effect to reduce the electron concentration in n-type few-layer MoS2. It can thus effectively modulate the electron transport and photoluminescence properties in few-layer MoS2. By monitoring the conductance change of few-layer MoS2 in varying concentration Hg2+ solutions, we further show that few-layer MoS2 transistors can function as highly sensitive sensors for rapid electrical detection of Hg2+ ion with a detection limit of 30 pM.

The layered transition metal dichalcogenides have attracted considerable interest for their unique electronic and optical properties. While the monolayer MoS 2 exhibits a direct bandgap, the multilayer MoS 2 is an indirect bandgap semiconductor and generally optically inactive. Here we report electric-field-induced strong electroluminescence in multilayer MoS 2 . We show that GaN–Al 2 O 3 –MoS 2 and GaN–Al 2 O 3 –MoS 2 –Al 2 O 3 -graphene vertical heterojunctions can be created with excellent rectification behaviour. Electroluminescence studies demonstrate prominent direct bandgap excitonic emission in multilayer MoS 2 over the entire vertical junction area. Importantly, the electroluminescence efficiency observed in multilayer MoS 2 is comparable to or higher than that in monolayers. This strong electroluminescence can be attributed to electric-field-induced carrier redistribution from the lowest energy points (indirect bandgap) to higher energy points (direct bandgap) in k -space. The electric-field-induced electroluminescence is general for other layered materials including WSe 2 and can open up a new pathway towards transition metal dichalcogenide-based optoelectronic devices.