The growing integration and power density of electronics require materials that combine efficient electromagnetic wave absorption with thermal management. However, synthesizing lightweight, processable 2D materials that exhibit strong electromagnetic attenuation alongside high thermal conductivity yet electrical insulation remains a challenge. Here, we present a vapor intercalation-deposition approach of merging graphite exfoliation and metal‑nitrogen‑carbon atomic-layer growth to synthesize a graphene bonded dual-atom FeNi-N-C heterojunction. FeCl3 in the graphite interlayer can coordinate with 2-methylimidazole and catalyze the formation of CC bonds between graphene and the FeNi-N-C layer during heating. The solution-processable heterojunction exhibits outstanding electromagnetic attenuation of a low reflection loss of −75.3 dB, a broad absorption bandwidth of 6.08 GHz at 1.75 mm, a radar cross-section reduction of 51.4 dB·m2. It also shows low electrical conductivity (0.775 S/cm) and high thermal conductivities (10.57 W·m−1·K−1 in-plane, 4.03 W·m−1·K−1 out-plane). Mechanistic studies demonstrate that interfacial coupling between graphene and Fe(Ni)-N4-C atomic layers synergistically boosts dipole polarization and dielectric loss for enhanced electromagnetic attenuation, and atomic-layer design enables the decoupling of electrical and thermal transport. This work offers a low-cost, scalable route to adaptable two-dimensional heterojunctions for integrated electromagnetic wave absorption and heat dissipation in next-generation electronics.

Solving the problems of carbon dioxide(CO2)emis-sions and energy scarcity by the development of highly selective,cost-effective,and reliable catalysts for the electrochemical reduc-tion of CO2 to useful carbon-based products would be very helpful.We report the synthesis of an efficient graphene-supported bismuth single-atom catalyst(BiSA-G)featuring a BiN4 coordination struc-ture for this purpose.The synthesis used tannic acid as a multifunc-tional ligand and ammonia as a nitrogen dopant.Using a scalable coordination chemistry approach,BiN4 sites were uniformly dis-persed on the graphene substrate and were found to have an out-standing ability for the conversion of CO2 to CO,with a high Fara-daic efficiency of 97.4%at-0.55 V(vs.RHE)and a high turnover frequency of 5230 h-1 along with outstanding stability.Density functional theory calculations confirmed that the BiN4 site serves as the dominant active center,simultaneously facilit-ating CO2 activation and the efficient formation of the crucial intermediate*COOH with a reduced free energy barrier.This dis-covery offers a new way for the atomic-scale design of high-efficiency catalysts for the electrochemical CO2 reduction reaction,potentially helping sustainable carbon use.

Methylmercury (MeHg) in coastal sediments poses significant ecological and human-health risks due to its high toxicity, strong bioaccumulation potential, and mobility within benthic environments. This study investigates the spatiotemporal distribution, preservation mechanisms, and historical burial fluxes of MeHg in surface sediments and sediment cores collected from Jiaozhou Bay (JZB), a semi-enclosed and urbanized bay in northern China. Surface sediments exhibited low-to-moderate MeHg concentrations (0.03-0.37 ng/g) with a pronounced east-west concentration gradient. Higher MeHg levels were found in the northeastern estuary and the bay mouth, primarily driven by elevated inorganic Hg inputs (from riverine and wastewater sources) and enhanced methylation potential. Correlation analyses revealed that MeHg concentrations in surface sediments were weakly and positively correlated with total Hg (p < 0.05). Furthermore, the %MeHg were significantly modulated by key environmental parameters, including total organic carbon, nitrogen, sulfur, and grain size (p < 0.05). In the sediment cores, Core 14 exhibited significant inter-annual variability with a gradual long-term increase; meanwhile, Core 20 showed a sharp increase in 2014-2015, and Core 28 recorded elevated values during the 1990s, 2016, and 2018. The sedimentary MeHg burial fluxes across the cores increased steadily over time, reaching a common peak around 2013-2017. This maximum accumulation is likely due to the combination of increased MeHg inputs and favorable methylation conditions. The maximal MeHg accumulation observed in the subsurface layers of this coastal bay raises significant concern regarding the ecological contamination risk posed by sediments acting as a persistent secondary source.

Abstract We report on the development of a fast high-voltage switch based on two N-channel enhancement mode Gallium Nitride (GaN) high-electron mobility transistors (HEMTs). The switch is capable of switching high voltages up to 250 V on capacitive loads with rise and fall times on the order of 20 ns and pulse width of 30 ns. Using this switch, ions have been extracted out from the trap and a beam with a narrow time distribution has been achieved in a multi-reflection time-of-flight mass spectrometer.

The application of electro-Fenton (EF) technology in soil remediation is severely impeded by complex soil matrices, which induce scaling and passivation that rapidly poison the active sites of catalytic cathodes and cause electrocatalytic failure. To circumvent this fundamental catalytic barrier, we propose a cathodic electronpumping strategy using a ligand-enhanced electro-Fenton (L-EF) system with an electrochemically inert but robust titanium cathode. Unlike traditional EF relying on cathodic surface O-2 reduction, the cathodic current in L-EF is decoupled from the electrode, enabling the activation of O-2 in the bulk solution to generate hydroxyl radical (center dot OH), constituting a "bulk activation" process. Comparative assessment across three representative soils (Alisols, Chernozems, and Ferralsols) revealed exceptional performance in Chernozems, with 89.44% phenol removal and center dot OH yields exceeding 4000 mu M. This superior performance was intrinsically linked to soil properties that enhanced the activation of soil-derived iron and promoted the formation of reactive Fe(II) species under the L-EF system. Mechanistic analysis further confirmed that center dot OH was primarily produced through the two-electron oxygen activation pathway (O-2 -> H2O2 -> center dot OH). Crucially, this chemically self-sustaining strategy exhibits relatively low electrical energy consumption (E-EO, 44.44-154.66 kWh t(-1) order(-1)) and good eco-compatibility, offering a robust paradigm for leveraging endogenous minerals to overcome electrode catalytic limitations. This work successfully overcomes the long-standing challenge of electrode passivation in heterogeneous media and provides a robust, chemically self-sustaining platform, marking a significant advancement and a paradigm shift in practical application of electrochemical soil remediation.

The miniaturization, intense integration, and high-density power of modern electronic and energy devices necessitate extensive management of thermal energy and electromagnetic waves. Creating lightweight, stable, and multifunctional materials to meet these demands remains a challenge. Here, we describe preparing graphene aerogel through the condensation dehydration of hydrophilic polymers and further forming scenario-adaptive multifunctional films through 2500 degrees C heat treatment and paraffin hybridization. The graphene materials exhibit extensive thermal management with high performances covering high thermal conductivity (up to 76.4 W center dot m-1 center dot K-1), superior heat dissipation, tunable electro-thermal conversion, cycling heat storage, and flame retardancy. Additionally, they provide tunable and effective electromagnetic interference shielding performances with high specific shielding effectiveness (up to an average of 91.6 dB, maximum of 123 dB) in a wide frequency range, featuring anti-corrosive absorption-dominant shielding across the X-band, Ku-band, and K-band. Surface engineering of graphene including tuning surface chemical groups and interface couplings contributes to flexible thermal management and electromagnetic shielding. This work might offer a green strategic approach to developing extensive thermal and electromagnetic wave managements of graphene materials.

Rare earth elements (REEs) are the "fuel" for high-tech industry, yet their selective recovery from complex waste matrices is challenging. Herein, we designed a 2D multilayered MXene Ti3C2Tx adsorbent for selective extraction of REEs in a broad pH range. By establishing strong Lewis acid-base interactions, extraction capacities of Ti3C2Tx to Eu(III) and Ho(III) reached 892.8 and 649.2 mg/g, respectively, even at pH 2.0. Following the Valence Matching Principle, the Ti3C2Tx adsorbent also demonstrated high selectivity for recovery of various REEs from real REEs processing wastewater and actual sludge from magnet manufacturing industry. To demonstrate the practical feasibility, a layer-stacked membrane of Ti3C2Tx supported on polyethersulfone substrate was fabricated for continuous recovery of REEs and exhibited excellent removal of Eu(III) (99.1 % at pH 5.0), showcasing its potential for large-scale applications. DFT calculations and material characterization demonstrated that chemisorption between Lewis acid (REEs cations) and Lewis base (F and O) sites is the main adsorption process involved in the uptake of Eu(III) and Ho(III). Finally, both the Ti3C2Tx adsorbent and membrane were successfully regenerated and reused via simple acid wash. Overall, the results demonstrate the Ti3C2Tx-based recovery as a promising path for sustainable harvesting of REEs.

Iron-based Prussian blue (Fe-PB) materials have been widely investigated as cathode materials for sodium-ion batteries owing to their unique open framework structure. However, the enhancement of electrical conductivity and the reduction of structural defects in Prussian blue analogues remain challenging. In this study, hollow layered Fe-PB materials with gradually inward-etched centers were successfully synthesized through a phthalic acid (PA)-assisted chelation and etching process. Compared to conventionally hydrothermally synthesized materials, the prepared Fe-PB was characterized by an increased specific surface area, shortened sodium-ion diffusion pathways, and reduced lattice water content, leading to significantly improved electrochemical properties. When evaluated as a cathode material for sodium-ion batteries, the etched Fe-PB demonstrated an initial specific capacity of 106.4 mAh g- 1 at a current density of 100 mA g- 1. After 500 charge/discharge cycles, a specific capacity of 78.8 mAh g- 1 was maintained, corresponding to a capacity retention rate of 74.1 % and a remarkably low capacity decay rate of 0.05 % per cycle. This work not only provides an effective strategy for improving the sodium storage performance of Fe-PB materials but also offers valuable insights into the hydrothermal synthesis of high-performance Prussian blue analogues with reduced lattice water content and enhanced electrochemical properties.

The utilization of nickel-based catalysts as alternatives to expensive platinum-based(Pt-based)materials for the hydrogen evolution reaction in acidic electrolytes has attracted considerable attention due to their potential for enabling cost-effective industrial applications.However,the unsatisfied cyclic stability and electrochemical activity limit their further application.In this work,nickel-molybdenum(Ni-Mo)alloy catalysts were successfully synthesized through a comprehensive process including electrodeposition,thermal annealing,and electrochemical activation.Owing to the synergistic interaction of molybdenum trinickelide(Ni3Mo)and molybdenum dioxide(MoO2)in Ni-Mo alloy,the catalyst display superior overall electrochemical properties.A low overpotential of 86 mV at 10 mA/cm2 and a Tafel slope of 74.0 mV/dec in 0.5 mol/L H2SO4 solution can be achieved.Notably,remarkable stability with negligible performance degradation even after 100 h could be maintained.This work presents a novel and effective strategy for the design and fabrication of high-performance,non-precious metal electrocatalysts for acidic water electrolysis.

Electrocatalytic conversion of carbon dioxide (CO2) to formate is an effective strategy for converting CO2 into valuable chemicals. However, synthesizing active catalysts with well-defined heterojunctions and large exposed surfaces remains challenging. Here, we present a one-pot synthesis method for a hybrid sulfide catalyst featuring surfactant-intercalated tin(IV) disulfide (SnS2) nanosheets heterojuncted with bismuth(III) sulfide (Bi2S3) needles. The surfactant hexadecyltrimethylammonium bromide (CTAB) plays a vital role in transforming the morphology of the components and the formation of their heterojunction. The resulting catalyst exhibits outstanding performance in reducing CO2 to formate, demonstrating the high formate Faradaic efficiency (FE) of over 90 % across a wide potential range from-0.8 to-1.3 V (vs. reversible hydrogen electrode (RHE)) and achieving a maximum FEformate of 97.2 % at-1.1 V (vs. RHE). In contrast, the partial current density of formate reaches about 350 mA cm- 2 at-1.35 V (vs. RHE) in the flow cell. Furthermore, the catalyst demonstrated exceptional stability, with a high selectivity towards formate production maintained at a current density of 156 mA cm- 2. Theoretical calculations and in situ Raman indicate that the SnS2/Bi2S3 heterojunction active sites optimize the free energy for the *H and *OCHO intermediates, thereby facilitating the formation and desorption steps of *HCOOH, ultimately leading to formate yield efficiently. Our investigation offers a strategic method and valuable insights for designing catalytic materials with rich interfaces for efficient CO2 reduction reactions.

An uneven Co-N-C layer coated on electrochemically-exfoliated graphene as an active support (E1/2 0.788 V) to stabilize low-amount Pt catalyst was synthesized. The catalyst exhibited superior oxygen reduction activity (0.72 A mgPt-1) and durability (10 mV loss after 50k cycles) in acid. Graphene reinforced the metal-support interaction, benefitting the conductivity, activity and durability of the catalyst.

Photocatalytic CO2 reduction to produce valuable chemicals is a promising strategy to address environmental issues and energy crisis. However, achieving high efficiency and selectivity for converting CO2 into higher-energy CH4 remains challenging due to the competitive two-electron reduction pathway producing CO. In this study, Cu2O clusters were strongly anchored onto ultrathin TiO2 nanosheets (Cu(I)-TiO2) using a simple photo-deposition method. Compared to pure TiO2, Cu(I)-TiO2 samples exhibited a significantly enhanced photocatalytic activity and selectivity for CO2-to-CH4. The presence of Cu2O can also enhance the photogenerated carrier separation and light absorption. By optimizing the amount of Cu2O, the CH4 production rate of 45.73 mu molg-1h-1 with selectivity up to 97.47% was achieved. Mechanistic investigations demonstrate that the presence of Cu2O lowers the formation energy barrier of *COOH, a key intermediate for the photocatalytic CO2 reduction. Moreover, Cu(I)-TiO2 promotes the adsorption and hydrogenation of *CO to *CHOx species, favoring CH4 production over CO. This work provides valuable insights for designing highly efficient and selective photocatalyst for CO2 reduction and deepens the understanding of reaction mechanism.

The need for bi-functional catalysts that facilit-ate both the oxygen reduction(ORR)and carbon dioxide re-duction(CO2RR)reactions arises from their potential to help solve the critical problems of carbon neutrality and renew-able energy conversion.However,there are few reports on the development of bi-functional catalysts for zinc-air bat-tery-driven CO2RR devices.We introduce a novel approach for synthesizing Fe2N/Fe3C species embedded in nitrogen-doped carbon nanofibers by electrospinning a solution of Hemin and polyacrylonitrile in N,N-dimethylformamide.The material has an exceptional catalytic performance,with a half-wave potential of 0.91 V versus RHE for the ORR and values of over 90%for both the selectivity and Faradaic efficiency for the CO2RR.The high catalytic performances are attrib-uted to the strong coupling between the Fe3C/Fe2N heterostructure and the Fe-N-C sites in the nitrogen-doped carbon nan-ofibers.Notably,both Fe3C and Fe2N play distinct roles in both the ORR and CO2RR.This investigation indicates a way for designing advanced carbon-based bi-functional catalysts for use in this field.

Lithium manganese iron phosphate (LMFP) is increasingly attracting attention in the industry due to its excellent performance advantages. However, its limited electrical conductivity and lithium-ion diffusivity still hinder its practical application. In this paper, we introduced a method for the synthesis of LiMn0.8Fe0.2PO4/C nano spherical composites by using cetyltrimethylammonium bromide (CTAB)-assisted hydrothermal method. The material doped with 1 mmol of CTAB(LMFP/C-1) significantly prevented particle agglomeration and reduced the particle size, which improved the electrical conductivity of the material and exhibited excellent multiplicative and cycling properties. The results showed that LMFP-1can release the initial specific capacity around 152.4 mAh center dot g- 1 at 0.1C, and the capacity retention rate was 94.35 % after 500 cycles at 1C. This research provides a method to improve the cathode materials for lithium-ion batteries.

The reduction of carbon dioxide (CO2) by electrochemical methods for the production of fuels and value-added chemicals is an effective strategy for overcoming the global warming problem. Due to the stable molecular structure of CO2, the design of highly selective, energy-efficient and cost-effective electrocatalysts is key. For this reason, graphene and its derivatives are competitive for CO2 electroreduction with their unique and excellent physical, mechanical and electrical properties and relatively low cost. In addition, the surface of graphene-based materials can be modified using different methods, including doping, defect engineering, production of composite structures and wrapped shapes. We first review the fundamental concepts and criteria for evaluating electrochemical CO2 reduction, as well as the catalytic principles and processes. Methods for preparing graphene-based catalysts are briefly introduced, and recent research on them is summarized according to the categories of the catalytic sites. Finally, the future development direction of CO2 electroreduction technology is discussed.