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Electroreduction of nitrate (NO3−) has emerged as a promising strategy for producing ammonia (NH3) at room temperature in recent years. However, the formation of the less electron-consuming H2 byproduct seriously limits the conversion efficiency of NO3− to NH3. In this study, we identify that N-doped Co3O4 can effectively convert NO3− to NH3 with a high performance (NH3 yield rate: 7.18 ± 0.59 mg h−1 cm−2, faradaic efficiency: 96.7 ± 0.88%), which is significantly higher than that of pure Co3O4 (NH3 yield rate: 4.95 ± 0.54 mg h−1 cm−2) and most reported Co-based catalysts (Table S1, ESI). Density functional theory (DFT) calculations coupled with X-ray absorption near-edge structure (XANES) experiments reveal that N-doping in Co3O4 releases more positive charge on the Co atom site due to charge compensation. This oxidized Co atom site enhances the adsorption of NO3− while weakening the adsorption of H+ through Coulombic interactions, thus improving NO3RR activity. Overall, our study provides an efficient electrocatalyst to avoid the formation of the H2 byproduct to facilitate the conversion of NO3− to NH3, and opens new avenues towards achieving green ammonia production by controlling Coulombic interactions. [ABSTRACT FROM AUTHOR]

LED packaging miniaturization has raised more requirements for LED materials. As a material contacting the LED chip directly, the reliability of LED non-conductive adhesive has also garnered increasing attention. This study optimized the formula for non-conductive adhesives for an imidazole curing system. The optimized composition of the adhesive is 25%wt for the curing agent and 30%wt for the silica. The prepared non-conductive adhesive has a 7-day pot life and 9-month storage stability. The shear strength reached 87 g and 72 g at 25 °C and 160 °C, respectively. The reliability of the LED modules packaged with the non-conductive adhesive was researched. The green and blue light intensity change was 4.7%, 43.7%, respectively, indicating good anti-aging properties. The blue light decay was mainly due to adhesive aging. The non-conductive adhesive effectively prevented "caterpillar" growth. This provides useful and practical guidelines for industry for applications of adhesive in different packages. [ABSTRACT FROM AUTHOR]

Ionically conducting eutectogels have gained popularity as temperature-tolerant and cost-effective substitutes for hydrogels and ionogels in flexible electronic devices. In this study, mechanically robust eutectogels with antibacterial properties were fabricated using a facile one-step process that relied solely on the physical entanglement of polymer chains. At low initiator concentrations, the vinyl monomers underwent radical polymerization in deep eutectic solvents (DESs), forming physically entangled and transparent eutectogels. The eutectogels exhibited excellent mechanical properties (tensile strength, elongation at break, and fracture energy of 8.04 MPa, 620.5%, and 28.69 ± 2.23 MJ m−3, respectively), a strong adhesion force, excellent ionic conductivity (0.43 ± 0.07 S m−1), and remarkable resistance to freezing and drying (−20 to 80 °C). Moreover, the eutectogels possessed superior self-healing abilities at room temperature without the need for external stimuli. As sensors, the fabricated eutectogels exhibited high sensitivity, thereby enabling the precise, real-time, and stable monitoring of human activities. The eutectogels have promising applications in wearable technology, healthcare devices, and human–computer interfaces. [ABSTRACT FROM AUTHOR]

The development of high-performance electromagnetic interference (EMI) shielding materials that minimize reflection is of paramount importance in the electronics industry. This study introduces a novel approach to fabricating multilayered composite films consisting of MXene and Fe3O4 nanosheets (FONS), which exhibit significantly enhanced EMI shielding effectiveness (SE) with reduced reflection characteristics. By leveraging the synergistic properties of highly conductive MXene and the magnetic properties of FONS, the composite films demonstrate a maximum SE of 34.3 dB within the X-band with a mere 0.17 mm thickness and a low filler content of 6.25 wt.%. The FONS contribute to an increased total EMI SE while concurrently suppressing the reflection SE, achieving a minimum reflection of only 4.2 dB. The alternating multilayered structure, characterized by dense distribution of MXene and the impedance matching capabilities of FONS/waterborne polyurethane layers, results in a pronounced interfacial polarization effect, which enhances the polarization loss. [ABSTRACT FROM AUTHOR]

In the realm of electromagnetic wave absorption materials, achieving a combination of broad absorption bandwidth, high absorption intensity, and practical versatility presents both a scientific challenge and an engineering necessity. This study introduces a lightweight, high compressibility poly-(methacrylimide) (PMI) composite foam with enhanced electromagnetic wave absorption properties. The multiwalled carbon nanotubes (MWCNT) and PMI were composited by ultraviolet (UV) photoinitiation prepolymerization, afterward combining the copolymerization curable-hot air method to prepare MWCNT/PMI composite foam. The resulting MWCNT/PMI composite foam with a minimal MWCNT content of less than 4.0 wt % exhibits a remarkable reflection loss of −55.0 dB and an extensive effective absorption bandwidth of 16.0 GHz within the 2–18 GHz range, attributable to its optimized porous structure and elevated dielectric loss. The complete frequency range of 2–18 GHz can be efficiently absorbed by MWCNT/PMI composite foam, making it ideal for broadband wave absorption. Additionally, composite foams all satisfy the requirements for lightweight design and high strength of microwave-absorbing materials due to its lightweight, good compressive strength, and heat resistance, making it more competitive in engineering applications. [ABSTRACT FROM AUTHOR]

Electroreduction of nitric oxide (NO) to NH3 (NORR) has gained extensive attention for the sake of low carbon emission and air pollutant treatment. Unfortunately, NORR is greatly hindered by its sluggish kinetics, especially under low concentrations of NO. Herein, we developed a chlorine (Cl) vacancy strategy to overcome this limitation over FeOCl nanosheets (FeOCl‐VCl). Density functional theory (DFT) calculations revealed that the Cl vacancy resulted in defective Fe with sharp d‐states characteristics in FeOCl‐VCl to enhance the absorption and activation of NO. In situ X‐ray absorption near‐edge structure (XANES) and attenuated total reflection‐infrared spectroscopy (ATR‐IR) verified the lower average oxidation state of defective Fe to enhance the electron transfer for NO adsorption/activation and facilitate the generation of key NHO and NHx intermediates. As a result, the FeOCl‐VCl exhibited superior NORR activities with the NH3 Faradaic efficiency up to 91.1 % while maintaining a high NH3 yield rate of 455.4 μg cm−2 h−1 under 1.0 vol % NO concentration, competitive with those of previously reported literatures under higher NO concentration. Further, the assembled Zn‐NO battery utilizing FeOCl‐VCl as cathode delivered a record peak power density of 6.2 mW cm−2, offering a new route for simultaneous NO removal, NH3 production, and energy supply. [ABSTRACT FROM AUTHOR]

Field grading composites showing nonlinear conductive performance are usually applied to protection for electrical systems. In this work, polyetherimide (PEI) matrix composite films with field-dependent nonlinear conductive behavior were fabricated by using a typical type of transition metal dichalcogenides, MoS2 as filler. The MoS2 filled PEI composite film showed a nonlinear coefficient of 6.92 at a relatively low filler content of 15 phr, which is the percolation threshold of this kind of composite film. Nonlinear conductive behavior of the MoS2/PEI composites was driven by tunneling effect. Conductivity of the 20 phr of MoS2 filled composite film increased for almost 3 magnitudes within 20 kV/mm. Enhanced dielectric constant was brought to PEI by the MoS2 fillers. The PEI containing 20 phr of MoS2 showed a dielectric constant of 6.1 at 1 kHz with dielectric loss still being low. This work revealed the potential of MoS2 being adopted as filler of field grading composites. [ABSTRACT FROM AUTHOR]

Making use of defects modification to P(VDF-TrFE) via either high energy electron irradiation treatment or copolymerizing VDF-TrFE with a small amount of chlorinated monomer to form a random terpolymer, we demonstrate that high electromechanical responses can be realized in P(VDF-TrFE) based polymers. It will be shown that in the stretched and irradiated 68/32 mol% copolymer, a transverse strain of 4.5% and a transverse electromechanical coupling factor [k.sub.31] of 0.65 can be induced under a field of 85 MV/m. In addition, the irradiated copolymer also exhibits a high elastic energy density, ~ 1 J/c[m.sup.3]. For PVDF based terpolymers such as P(VDF-TrFE-CFE) terpolymer (CFE: chiorofluoroethylene), an electrostrictive strain of more than 7% can be obtained. To elucidate the microstructure changes due to the defects modification in P(VDF-TrFE) based polymers, synchrotron X-ray measurement was carried out on the irradiated copolymers and the results show that, the irradiation converts the polar-phase into a non-polar phase. In addition, X-ray date show that the polar-phase can be induced, at the expense of the non-polar phase, by external fields, confirming that the field induced conformation change is responsible for the observed high electromechanical responses. Although the modified PVDF based polymer exhibits the highest room temperature dielectric constant (60 versus below 10), it is still far below those in the inorganic materials. Experimental results show that by using delocalized electrons in conjugated bonds an all-organic composite with a dielectric constant more than 400 can be achieved. As a result, a strain of near 2% with an elastic energy density higher than 0.1 J/c[m.sup.3] can be induced under a low applied field of 13 V/[micro]m. The strain is proportional to the applied field and the composite has an elastic modulus near 1 GPa. Index Terms--Electroactive polymers, relaxor-ferroelectric polymers, high dielectric constant polymers, electrostriction, field effect actuators.

Author(s): Q. M. Zhang (corresponding author); Hengfeng Li; Martin Poh; Feng Xia; Z.-Y. Cheng; Haisheng Xu; Cheng Huang Electroactive polymers (EAPs) can behave as actuators, changing their shape in response [...]

Electronic defect states in catalysts are recognized as highly effective active sites for enhancing the low‐concentration electroreduction of NO to NH3 (NORR). Their structures dynamically evolve with applied electrode potentials, allowing the active sites to adjust interactions with intermediates, thereby improving electrocatalytic performance. However, the dynamic changes in these interactions under applied potentials remain poorly understood, hindering the design of more diverse electrocatalytic systems. Herein, we developed a strategy that unitizes electrode potential to control the interactions between active sites and intermediates over oxygen vacancy‐modified TiO2 (VO−TiO2−x) to enhance NORR performance. By combining state‐of‐the‐art constant inner potential (CIP) DFT calculations with in situ (spectro)electrochemical measurements, we investigated how the electrode potential influences these interactions in NORR. The results clearly demonstrate that applying an external potential alters the spatial symmetry of degenerate orbitals of Ti3+ to facilitate the generation of key intermediates for NO‐to‐NH3 conversion. Therefore, the VO−TiO2−x catalyst exhibited superior NORR performance with a NH3 Faradaic efficiency up to 76.4 % and a high NH3 yield rate of 632.9 μg h−1 mgcat.−1 under 1.0 vol % NO atmosphere, which is competitive with those of previously reported works under higher NO concentration (above 10 vol %). Remarkably, the NORR process achieved a record‐breaking NH3 yield of 2292.7 μg h−1 mgcat.−1 in a membrane electrode assembly (MEA) electrolyzer under the same conditions. This study opens a new avenue for enhancing electrocatalytic activity by adjusting operating conditions, thereby transcending the limitations of material design. [ABSTRACT FROM AUTHOR]