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[Display omitted] Strong absorption and large bandwidth are two contributors to materials' absorbing performance. In this work, a series of multi-element core-shell magnetic nano-particle composite layered graphene absorbing materials CoFe 2 O 4 @C/rGO (CCr) were prepared by adjusting carbon shell thickness. The CCr at a low thickness achieved strong microwave absorption and a wide effective absorption bandwidth. Not only the core-shell structure of the magnetic nanoparticle CoFe 2 O 4 @C (CFO@C) increases the interface loss, but both the coating carbon shell and the core CoFe 2 O 4 (CFO) are beneficial to improve impedance matching. Due to the synergistic effect of the dielectric and magnetic properties of graphene and ferrite, CCr possessed high absorption performance, and its minimum reflection loss reached (R Lmin) −52.5 dB when the thickness was only 2 mm. At the same time, the effective absorption bandwidth (EAB) was 5.68 GHz when the thickness was only 1.7 mm. The chemically stable core-shell dielectric nanocomposite provided a new solution for preparing materials with excellent chemical structure and high absorbing properties. [ABSTRACT FROM AUTHOR]

A high-gain, low-offset, and low-power auto-zero operational amplifier with rail-to-rail input/output is proposed. Based on a time-interleaved charge pump high-voltage on-chip internal power supply, the PMOS differential pair input configuration will achieve a rail-to-rail input range with constant transconductance. Time-interleaved auto-zero continuously eliminates the input offset voltage of the operational amplifier in the time domain. An nA-level bias circuit to realize low power. The operational amplifier circuit is based on a 65 nm CMOS process. Under 1.2V power supply voltage and temperature 27 °C, the input offset voltage of the operational amplifier is 3.16 μV and the input offset current is less than 20 pA. The temperature drift coefficient of offset voltage is 0.005 μV/°C between −40 °C and 90 °C. The variation rate of input transconductance is only 5.6 % among the rail-to-rail input range. The equivalent DC gain is 106.4 dB, the unit gain bandwidth is 0.54 MHz, the phase margin is 76.5°, and the power consumption is about 0.19 mW. The layout area is 0.83 × 0.75 mm2. [ABSTRACT FROM AUTHOR]

Biomass, as a continuously available raw material, is widely used to produce hard carbon. However, many researchers have ignored the natural special morphology of biomass and the influence of oxygen on the sodium storage performance. Here, we use the cilia of the setaria viridis as the precursor to obtain a fiber-like oxygen-doped hierarchical porous hard carbon (SVC). The sodium storage mechanism of SVC is studied by controlling the pyrolysis temperature. Studies have shown that the natural fibrous structure and vertical holes of SVC can provide channels for the rapid penetration of electrolyte. The appropriate nanocrystal size affords commodious circumstances for the insertion of Na+. More importantly, the increase in carbonization temperature will change the bonding mode of carbon and oxygen, promote the rupture of single bonds and retain the existence of double bonds, which is beneficial to the improvement of coulombic efficiency and reversible capacity. The hybrid sodium storage mechanism composed of insertion behavior and capacitance behavior promotes SVC to have higher reversible capacity (285.4 mAh g−1 at 0.05 A g−1) and excellent rate performance (90.7 mAh g−1 at 5 A g−1). This research provides some new ideas for the study of hard carbon. [ABSTRACT FROM AUTHOR]

Heteroatom doping is an effective strategy to improve the sodium storage capacity of carbon materials. However, the current heteroatom doping preparation method is complicated and it is difficult to achieve large-scale industrial production. In this paper, starch is used as precursor to obtain N, O, P co-doped carbon network (NOP–CN) through a simple calcination. Experimental and theoretical calculations were used to systematically analyze the effect of N, O, P co-doping on the sodium storage capacity of the carbon material. Compared with diatomic (N, O) doping, the introduction of P atoms further enhances the conductivity of the carbon structure, while distorting the graphite layer, generating more active sites and defects, increasing the graphite layer spacing. At the same time, the unique three-dimensional network of NOP–CN provides a fast transmission channel for sodium ions. Therefore, NOP–CN exhibits excellent electrochemical performance. The reversible capacity can reach 341.3 mA h g−1 at 0.05 A g−1. After 2000 cycles at 5 A g−1, the capacity can remain 119.1 mA h g−1. The excellent sodium storage capacity and simple synthesis strategy in this study provide an efficient and convenient method for the design of heteroatom-doped carbon materials. Image 1 [ABSTRACT FROM AUTHOR]

A simple preparation method of the anode is designed for sodium ion battery. The bimetallic selenide (CoSe 2 /ZnSe) and nitrogen-doped carbon composite materials are obtained by selenization and carbonization of the metal organic framework precursors, and applied to high-performance sodium ion storage. The ingenious nanostructure is shown in that CoSe 2 and ZnSe nanoparticles are evenly distributed on the fusiform flake carbon skeleton. This synergy can improve the capacity and conductivity, and inhibit the volume expansion during the cycle. For electrochemical performance analysis, the prepared 1:1-CoSe 2 /ZnSe@NCC electrode shows a high discharge specific capacity of 621.5 mA h g-1 at 0.1 A g-1 after 100 cycles (coulomb efficiency close to 100%, capacity retention reaches ~ 90%), and has advantages over other electrodes in terms of rate performance and reaction kinetics. The excellent electrochemical performance confirms the successful development of a high performance electrode for sodium ion storage by this strategy. [ABSTRACT FROM AUTHOR]

Development of superior heterogeneous photocatalyst for hydrogen (H 2) evolution with promising pollutant degradable capacity is a significant feature but then again thought-provoking for shaping the energy and environmental issues. In this regard, a photocatalytic H 2 evolution using nano diamond (ND) semiconducting materials having pollutant degradable capacity for Rhodamine B dye (RhB) has been rarely reported and hence predicted to the sustainable energy. Productive characteristics such good chemical stability, super hardness, nanometer size, biocompatibility and thermal conductivity, ND is a capable and highly valuable powder physical material. Non-uniform and agglomeration dispersion spread of ND in different solvents are the main problems preventing ND from the wide-use in commercial applications. Upon 535 nm solar light excitation, the fabricated ND sample exhibit remarkable photocatalytic H2 production with a HER of about 400 μmol h−1 than pristine ND (197 μmol h−1). Additionally, this H2 generation dramatically enhances the quantum yield, indicating the H2 terminated sites work as electron reservoirs. Precisely, the kinetic constant pseudo-order of FND for photodegradation of RhB was higher as compared with pristine ND. As such, the results show an important step toward tailor-designed and explain the vital role of FND composites for the rational motifs of fruitful photocatalyst with effective pollutant degradable capability for future demand. • A ball milling Functionalization of ND. • An twice improved HER was observed for FND (400 μmol/h) than pure ND (197 μmol/h). • Pseudo-order kinetic constant of FND for RhB was higher as compared with ND. [ABSTRACT FROM AUTHOR]

We integrate a potential conjugated donor-acceptor (DA) co-monomer such as 2, 3-dichloroquinoxaline (DCQ) within the structure of polymeric carbon nitride (PCN) by a facile one-pot co-polymerization process. The hydrogen evolution rate (HER) for pure CNU with 14.2 μmol/h while for CNU-DCQ 18.0 it was estimated at 124.9 μmol/h which remarkably fueled almost seventy times more than blank sample. Similarly, the oxygen evolution rate (OER) analysis indicates the production 0.2 μmol/h−1 (visible) and 1.5 μmol/h−1 (non-visible) for CNU. However, the OER of copolymerized CNU-DCQ 18.0 is found to be 1.9 μmol/h−1 (visible) and 12.8 μmol/h−1 (non-visible) which almost nine times higher than parental CNU. • DCQ integrated copolymer (CNU-DCQ) were prepared by facile one-pot thermo-induced co-condensation reaction. • The integration of DCQ was supported by DFT and TD-DFT calculations. • CNU-DCQ copolymer possess a high surface area with good electric properties. • An eight-time improved HER was observed for CNU-DCQ 18.0 (124.9 μmol/h) than pure CNU (14.2 μmol/h). • The OER, generates 0.2 μmol/h−1 and 1.5 μmol/h−1 (under visible and non-visible) for pure CNU, whereas the copolymerized CNU-DCQ 18.0 produce 1.9 μmol/h−1 (visible) and 12.8 μmol/h−1 (non-visible) respectively. • The HER for pure CNU with 14.2 μmol/h while for CNU-DCQ 18.0 it was estimated at 124.9 μmol/h which remarkably fueled almost seventy times more than blank sample. The OER analysis indicates the production 0.2 μmol/h−1 (visible) and 1.5 μmol/h−1 (non-visible) for CNU. However, the OER of copolymerized CNU-DCQ 18.0 is found to be 1.9 μmol/h−1 (visible) and 12.8 μmol/h−1 (non-visible) which almost nine times higher than parental CNU. Research based on the full water splitting via heterogenous semiconducting photocatalyst is a significant characteristic nevertheless challenging for determining the energy and environmental crises. With respect to this, a photocatalytic water splitting by visible light through heterojunction semiconductors has been anticipated as a route to the sustainable energy. For the first time, we integrate a potential conjugated donor–acceptor (DA) co-monomer such as 2, 3-dichloroquinoxaline (DCQ) within the structure of polymeric carbon nitride (PCN) by a facile one-pot co-polymerization process. The DCQ which is acting as an organic motif that simulates a nucleophilic attack on the hosting PCN semiconductor which extends into a long chain of the polymer having enormous surface area and remarkable photocatalytic activity for H 2 and O 2 evolution as compared to the parental CNU. The supremacy of molecular geometry with DA ratio is effectively studied by absorbent, calculated band gap and migration of electrons on the photocatalytic performance of as-synthesized CNU-DCQx co-polymer. The density functional theory (DFT) calculation deliver supplementary evidence for the positive incorporation of DCQ in to the PCN matrix with reduced band gap upon copolymerization. Further, the hydrogen evolution rate (HER) for pure CNU with 14.2 μmol/h while for CNU-DCQ 18.0 it is estimated at 124.9 μmol/h which remarkably fueled almost eight times more than blank sample. Similarly, the oxygen evolution rate (OER) analysis indicates the production 0.2 μmol/h (visible) and 1.5 μmol/h (non-visible) for CNU. However, the OER of copolymerized CNU-DCQ 18.0 is found to be 1.9 μmol/h (visible) and 12.8 μmol/h (non-visible) which almost nine times higher than parental CNU. Hence, the output of this work reflects as an important step on the way to tailor-designed and elucidate the promising role of D-π-A system for the rational motifs of productive photocatalysts for forthcoming request. [ABSTRACT FROM AUTHOR]

In this paper, a self-healing operational amplifier circuit to deal with hot carrier injection (HCI) effect is proposed. An inverter-based operational amplifier is implemented. The influence degree of HCI effect to performance of the operational amplifier is studied which utilizes an equivalent circuit model of HCI effect. A monitoring circuit is proposed to monitor the degree of HCI degradation. A charge pump circuit is utilized to generate a corresponding voltage according to the result of monitoring circuit. The output voltage of the charge pump circuit is feedback to tune the substrate voltage of the operational amplifier (and the monitoring circuit) to mitigate degradation. The simulation results show that the self-healing operational amplifier can maintain the performance at low temperature and room temperature for 50 years (and high temperature for 30 year) under HCI effect. The gain of the inverter-based operational amplifier without self-healing is reduced from 45 dB to 9.6 dB after 50 years, and the gain of the self-healing operational amplifier will maintain at about 46 dB among 50 years. The influence of HCI effect on bandwidth and phase margin is less than that of temperature and process corner. The lifetime of self-healing operational amplifier circuit is >5 times longer than lifetime of based on inverter operational amplifier circuit without self-healing. In addition, the self-healing operational amplifier is robust to process corner. • The impact of HCI effect on op amp performance is studied，using an equivalent circuit model of HCI effect • A compensation circuit for HCI effect is proposed at low supply voltages. This compensation circuit can work properly after hot carrier degradation • The self-healing operational amplifier can maintain the performance at low temperature and room temperature for 50 years (and high temperature for 30 year) under HCI effect • Gain of self-healing op-amp maintained at ~46 dB over 50 years, while non-self-healing op-amp's gain dropped to 9.6 dB. • Self-healing op-amp has more than 5timers longer lifetimes than non-self-healing one and is robust to process corner. [ABSTRACT FROM AUTHOR]

The development of high dielectric loss and magnetic loss for radar absorbing material is a long-term pursuing and under a close scrutiny. Most of the researches have been focused on exploring absorber materials with good absorption performance and at the same time with a good electrical conductivity. To develop a new absorber material will also have significant impacts on boosting the dielectric loss and magnetic loss. Herein, 3D spherical NiCo 2 S 4 (NCS)-based composite has been fabricated via a mild, simple and useful hydrothermal strategy and the electromagnetic wave absorbing properties have been investigated through comparison among NCS, acidified carbon nanotubes (a-CNT)/NCS, reduced graphene oxide (r-GO)/NCS and r-GO/a-CNT/NCS. The experimental results show that the optimal concentration of NiSO 4 ·6H 2 O to synthesize the composites is 6 M. Furthermore, the frequency bandwidth has been broadened and the maximum absorption peaks have been increased after adding the modified agent. The maximum frequency bandwidth of r-GO/a-CNT/NCS is 5.1 GHz below −5 dB and 2.7 GHz below −10 dB respectively, the maximum absorption peak is −35.8 dB at 8.1 GHz. Schematic illustration of the fabrication process for the r-GO/a-CNT/NCS. Image 1 • Different concentration of pure NCS causes various microstructure and properties. • The addition of a-CNT and r-GO can greatly improve the EM absorption properties. • The maximum frequency bandwidth is 5.1 GHz below −5 dB. • The maximum absorption peak is −35.8 dB at 8.1 GHz. [ABSTRACT FROM AUTHOR]

Highlights • EG/CuO@C is prepared by self-combustion and hydrothermal treatment. • The model of EG/CuO@C structure explain the electrochemical performance. • The EG/CuO@C has the excellent capacitance. Abstract Expanded graphite embedded with CuO nanospheres coated with carbon (EG/CuO@C) is in-situ prepared by self-combustion and hydrothermal treatment methods The component analysis of the composite is carried out using X-ray diffraction and its morphology and microstructure are characterized using field emission scanning electron microscopy (FESEM) and transmission electron microscope (TEM). The electrochemical performance is examined by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy in 6 M KOH solution as electrolyte. The experimental results revealed that the EG/CuO@C composite remained porous structure, which is beneficial for supercapacitance. The EG/CuO@C exhibits the high specific capacitance of 335 F g−1 and the capacitance retention of 87% after 8000 cycles at the scan rate of 10 mV s−1. Moreover, the EG/CuO@C composite remains high energy density of 14.03 Wh kg−1 at the power density of 10.1 kW kg−1. [ABSTRACT FROM AUTHOR]

In this paper, the performance degradation of a bandgap reference circuit with curvature compensation under the hot carrier injection (HCI) effect is studied, and a self-healing circuit is proposed. The intrinsic performance of the curvature compensation bandgap circuit achieved a temperature coefficient (TC) of 1.949 ppm/°C and an output reference voltage of 384.748 mV under a 1.2 V power supply voltage between −40 °C to 125 °C. The TC of the reference circuit will increase to 8.033 ppm/°C and the output reference voltage decreases to 384.318 mV after 50 years under the HCI effect. The study found that the gain decrease of the op-amp in the reference circuit leads to a decrease in the output voltage, and the decrease of the compensation current in the curvature compensation circuit leads to the degradation of the TC. A self-healing circuit is designed to mitigate the impact of the HCI effect. The simulation results show that the TC of the self-healing reference circuit is 3.934 ppm/°C and the output reference voltage is 384.655 mV after 50 years under the HCI effect. • The performance degradation of the reference circuits consists of two main causes. • Under the HCI effect, the gain of the op-amp decreases causing the circuit reference voltage to decrease. • A decrease in compensation current leads to a decrease in the temperature coefficient of the circuit. • Time proportional voltage and circuit bias changes are used to reduce the impact of the HCI effects. [ABSTRACT FROM AUTHOR]

Fabrication of highly elastic three-dimensional aerogel adsorbents with outstanding adsorption capacities is a long pursuit for the treatment of industrial contaminated water. In this work, a magnetic reduced graphene oxide (rGO)/Fe 3 O 4 /carbon nanotubes (CNTs) aerogel material was constructed by the electrostatic attraction between the negatively charged GO and positively charged CNTs following a one-pot water bath treatment. The as-synthesized aerogel demonstrated high compressive stress (28.4 kPa) and lower density (24.11 mg/cm3) with exceptional adsorption capacities for versatile adsorbates which are attributed to CNTs and magnetic Fe 3 O 4 nanoparticles. The effect of pH, initial concentration of adsorbates (dyes, Cd (ІІ) ions, organic solvents, and pump oil), content of CNTs and cyclic times on the adsorption capacities of the aerogel were investigated in detail. Furthermore, from simulation, the adsorption kinetics, and thermodynamics of the aerogel for adsorbates were more satisfied by endothermic quasi-second-order kinetic model with characteristic physical adsorption. Thus, the optimized rGO/Fe 3 O 4 /CNTs-10 aerogel adsorbent can be used as a powerful and versatile tool to deal with contaminated industrial or domestic wastewater. [Display omitted] • Aerogel was fabricated via electrostatic attraction and subsequent one-pot water. • Magnetic rGO/Fe 3 O 4 /CNTs aerogel with high mechanical stability was fabricated. • Aerogel achieved outstanding adsorption capacity for versatile adsorbates. • The produced aerogel demonstrated an almost 100% initial adsorption capacity. [ABSTRACT FROM AUTHOR]

Carbon fiber core-shell materials with three-dimensional structures have been proven to be electromagnetic wave absorbing materials with excellent performance. Although research on composite material structural frameworks is still in a state of limited understanding, their attractive results have been widely recognized. In this work, Mil88 A magnetic nanoparticles were implanted into carbon fibers (CF) and composite with transition metal sulfides to prepare flower-shaped MoS 2 coated carbon fibers/Mil88 A core-shell nanorods with adjustable microwave absorption. The introduction of Mil88 A and its attachment to the MoS 2 shell. Through the synergistic effect of the three, the dielectric loss is increased, and the polarization relaxation process is enhanced, thereby improving the impedance matching and optimizing the material's performance. After testing, when the thickness is only 2.5 mm, The minimum reflection loss of the obtained CF-Mil88 A@MoS 2 (CMM) reaches −70 dB, and the effective absorption bandwidth (EAB) reaches 4.68 GHz. [Display omitted] • The CMM exhibits excellent absorbing properties, its RL min reaches −70 dB, and the corresponding EAB is 4.68 GHz. • The designed multi-shell heterostructure and flower-shaped MoS 2 promote multiple reflections of electromagnetic waves. • Exploring the effects of carbonization temperature and the introduction of TMDs on electromagnetic wave absorption. • The Mil88A after high-temperature annealing provide magnetic loss and improve impedance matching. [ABSTRACT FROM AUTHOR]

A mononuclear titanium single crystal C 36 H 40 O 8 Si 3 Ti was synthesized and designed as a molecular precursor to produce silica supported single site Ti decorated Au catalysts of high activity and selectivity. Single site Ti–O species were successfully deposited onto Au nanoparticles supported on SiO 2 by simple grafting procedures. X-ray absorption spectroscopy and diffuse reflectance ultraviolet spectroscopies were used to investigate the structures and chemical natures of the titanium species around gold surface. Increasing the introduction of molecular precursor increased the titanium loading which allowed in-dependent control of Ti loading in the catalyst. When Ti loading increased to 3 wt% the gold NPs was still smaller than 2 nm and the method generated Ti–O units was remained highly dispersed around Au NPs. These samples were further tested as catalysts in selective oxidation of cis-cyclooctene in a stream of O 2 . They exhibited excellent catalytic activities and selectivities and the turnover frequencies (TOFs) achieved 83 h −1 . Moreover the catalysts can be retrieved by simple filtering from the reaction pot without diminishment of catalytic activity many times. All in all the results confirmed the important role of both the Au and isolated Ti–O species at the perimeter in the reaction and demonstrated that mononuclear Ti complex was facilitated to produce supported epoxidation catalysts as precursors. [ABSTRACT FROM AUTHOR]

3D printing is a fast-emerging technology, and a shape is fabricated using layer-by-layer deposition of a material in a bottom-up manufacturing operation. Here a porous nickel/polyaniline nanocages multiscale supercapacitor synthesized using 3D printing technology is fabricated. The porous structure of iron-nickel and polyaniline nanocages can increase the specific surface area which lead to enhance the specific capacitance. 3D printing technology is presented in energy devices to accurately fabricate the delicate structure. [ABSTRACT FROM AUTHOR]

Coiled amorphous carbon nanotube (CACNT) array was prepared by chemical vapor deposition method. The experimental results indicated that the length of as-prepared CACNT array was about 30 μm. The electromagnetic wave absorbing properties were studied through comparison among CACNTs, CACNT-La(NO 3 ) 3 , CACNT-(Fe, Co, Ni) and CACNT-reduced graphene oxide (RGO). The experimental results showed the maximum frequency bandwidth of CACNT-(Fe, Co, Ni) was 6.4 GHz below −5 dB and 2.3 GHz below −10 dB separately. Compared to the pure CACNTs, all the frequency bandwidth had been broaden after adding the modified agent. Meanwhile, the additive of rare earth ions La 3+ could effectively increase the maximum absorption peak (−17.94 dB at 8.96 GHz). [ABSTRACT FROM AUTHOR]

Amorphous carbon nanotube (ACNT)/sulfur composites were prepared by solution reaction method. The electrochemical results showed that both ACNT/S composite and ACNT/S mixture had a first reversible capacity of 1020 mA h·g −1 , and the capacity retention of ACNT/S composite was 77% after 100 cycles while that of ACNT/S mixture was only 35% with the initial capacity being 850 mA h·g −1 . The experimental results showed that the reversible lithium insertion capacity of the composite was obviously high and the cycling stability was good, which was mainly due to the solid and uniform dispersion of the sulfur and amorphous carbon nanotube matrix in the composite. [ABSTRACT FROM AUTHOR]

A composite with hierarchical layering structure characteristics was prepared for electromagnetic interference shielding applications. In this composite, highly conductive polyanilines (PANI) acted as a filler to shield electromagnetic waves and the “strong” aramid nanofibers (ANFs) film played as a matrix material to provide good mechanical property. This composite film with a thickness of several micrometres displayed a shielding effectiveness as high as 30 dB, a mechanical strength of 179 MPa, as well as good stability. These performances combined because the extended PANI molecules which have a very similar molecular structure with aramid molecules “attached” strongly on the surface of aramid nanofibers to form the highly conductive interconnected networks, and the hierarchical layering structure of ANF matrix was reserved. This composite could find potential applications for electromagnetic wave shielding especially when they are coated on curved surfaces and operated with frequent folding and/or stretching. [ABSTRACT FROM AUTHOR]

The pursuing aim of high reflection loss and broad frequency bandwidth for electromagnetic wave (EMW) absorbing materials is a long-term task and under a close scrutiny. To construct rational microstructures for the absorber have significant impacts on increasing reflection loss and broadening frequency bandwidth. Herein, we presented a sandwich microstructured expand graphite (EG)/BaFe 12 O 19 (BF) nanocomposite successfully prepared by in-situ sol-gel auto-combustion method. The experimental results showed that EG/BF nanocomposite has better EMW absorbing performance than pure EG and BF, the sandwich microstructured EG/BF connected with carbon nanotubes (CNTs) could further improve the electromagnetic performance effectively. The obtained CNT/EG/BF nanocomposite exhibited a saturation magnetization of 26.5 emu g −1 at room temperature and an excellent EMW absorbing performance. The maximum reflection loss of the sandwich microstructured CNT/EG/BF composites with a thickness of 1 mm was up to −45.8 dB and the frequency bandwidth below −10 dB could reach to 4.2 GHz within the frequency range of 2–18 GHz. The research results indicated that the prepared nanocomposite showed great potential as a new type of microwave absorbing material. [ABSTRACT FROM AUTHOR]

Three-dimensional (3-D) graphene foam/PANI nanorods were fabricated by hydrothermal treatment of graphene oxide (GO) solution and sequentially in-situ synthesis of PANI nanorods on the surface of graphene hydrogel. 3-D graphene foam was used as substrate for the growth of PANI nanorods and it increases the specific surface area as well as the double layer capacitance performance of the graphene foam/PANI nanorod composite. The length of the PANI nanorod is about 340 nm . PANI nanorods exhibited a short stick shape. These PANI nanorods agglomerate together and the growth orientation is anisotropic. The highest specific capacitance of 3-D graphene/PANI nanorod composite electrodes is 352 F g −1 at the scan rate of 10 mV s −1 . [ABSTRACT FROM AUTHOR]

The composite of carbon foam with Ni-Zn ferrite as additive has been developed via foaming and carbonization process for electromagnetic interference shielding, using coal tar pitch as precursor and Ni-Zn ferrite as an additive. It was observed that the shielding effectiveness (SE) over the X-band frequency is enhanced along with the increase of Ni-Zn ferrite additive amount. The carbon foam with 15 wt% Ni-Zn ferrite shows a SE of 42 dB, which has a promising application prospect. The electromagnetic interference shielding mechanism of carbon foam with different amount of Ni-Zn ferrite additive is discussed in the work. An absorption-dominant mechanism, which is mainly associated with the magnetic property determined by the amount of Ni-Zn ferrite additive, has been revealed. It is also found that the mechanical strength of resultant carbon foams increases firstly and then decreases with the continuously increased amount of Ni-Zn ferrite additive. [ABSTRACT FROM AUTHOR]

An equivalent circuit model of the negative bias temperature instability (NBTI) effect in 65 nm P-MOSFET is presented in this paper. Based on an existing P-MOSFET model of a 65 nm CMOS foundry PDK (Process Design Kit) and several basic electrical components and arithmetic cells in the EDA (Electronics Design Automation) library, an equivalent circuit model for NBTI degradation has been achieved. The electrical components and arithmetic cells include voltage source, voltage-controlled voltage source, voltage-controlled current source, adder, and multiplier. The equivalent circuit model includes five tunable input parameters: gate width (W), gate length (L), temperature (temp), stress time (t), and process corner (typical/fast/slow). The model takes into account the effects of drain-source, drain-gate, and gate-source voltage stress states. The effect of process corner on NBTI is also considered. The simulation results show that the performance curve of this P-MOSFET equivalent circuit model is consistent with the measured data in some published literature. This equivalent circuit model can be utilized for long-term reliability IC design. • This model provides five tunable input parameters which include gate width (W), gate length (L), temperature (temp), stress time (t), and process corner (typical/fast/slow) • The process corner option is seldom mentioned in other published literatures. • The equivalent circuit model is well compatible with EDA tools. • The equivalent circuit model has high accurate, and the simulation results of this model is well fitted with the measured results in other literatures. [ABSTRACT FROM AUTHOR]

The hot carrier injection (HCI) effect is an essential factor for the reliability of N-MOSFET. Under long-term usage time, the HCI effect will affect the threshold voltage, transconductance, saturation drain-source current of N-MOSFET, etc. It will seriously affect the performance and lifetime of products. The current model for HCI effect simulation is mainly by modifying the SPICE model of N-MOSFET, which requires complex experiments and parameter extraction. This paper establishes an HCI effect equivalent circuit model for a 65 nm N-MOSFET. Based on the N-MOSFET model in a 65 nm Process Design Kit (PDK), essential electrical components and arithmetic components (which are provided by EDA tools), this equivalent circuit model achieves the HCI effect simulation. This equivalent circuit model offers five tunable input parameters for the user, which are channel width (W), channel length (L), ambient temperature (Temp), stress time (Year), process corner (fast, typical, slow). The effect of gate-source voltage, drain-source voltage, and gate-drain voltage on HCI effect is included in this model. The simulation results of this model are compared with the measured results in other literatures, and the results are fitted well. • This equivalent circuit model provides five tunable input parameters, especially the process corner option. • The equivalent circuit model is well compatible with EDA tools. • The equivalent circuit model is a hybrid of empirical model and physical model. It has high accurate, and the simulation results of this model is well fitted with the measured results in other literatures. [ABSTRACT FROM AUTHOR]

Hierarchical structural design has been proved to be a new strategy for fabricating high-performance microwave absorbers, so some researchers use low–dimensional components to construct continuous networks for better performance. In this work, the novel hierarchical carbon fibers@ZIF–67@MoS 2 film with tunable and efficient electromagnetic wave (EMW) absorption performance was obtained by the electrostatic spinning of ZIF–67 in the interior of carbon fibers and subsequent hydrothermal of MoS 2. By the synergistic effects from the ZIF–67 particles increasing the magnetic loss and MoS 2 at the outer layer improving the impendence matching, the absorption property of CPZM–1 could be summarized as follow: the optimal reflection loss(RL) was −72.7 dB with a thickness of 2.6 mm at 10.0 GHz and the corresponding effective absorption bandwidth (EAB) of 9.8 GHz covered whole X and Ku band. Moreover, by adjusting the load of ZIF–67, CPZM–5 achieved the maximum EAB of 12.5 GHz. [ABSTRACT FROM AUTHOR]

The improved physicochemical immobilization and catalytic redox conversion of lithium polysulfides (LiPSs) intermediates are considered to be a desirable solution to enhance the sulfur electrochemistry in lithium-sulfur (Li–S) batteries. Herein, we for the first time, reported the fabrication of the core-shell structure composed of cobalt-doped carbon nano-tube (CNT) assembled polyhedron core derived from the cobalt metal-organic frameworks (Co-MOFs)@graphitized porous carbon aerogel shell as the sulfur reservoir material for Li–S batteries. The obtained sulfur cathodes exhibited excellent electrochemical performance, including a high reversible capacity (939.9 mAh g−1 at 0.1C), outstanding areal capacity (3.35 mAh cm−2 after 50 cycles, under a low electrolyte/8.3 μL m g s − 1 ), and superior cycling stability (the capacity decay rate of 0.087% per cycle after 500 cycles at 1C). The improvement in electrochemical performance could be attributed to the unique core-shell architecture: the multiple polyhedron Co–C cores not only provide a multiple-point catalytic center for LiPS conversion, but also serves as the polar material to inhibit the migrating of polysulfides by chemical interaction; More importantly, the graphitized porous carbon aerogel shell provides a fast transport channel for Li+/e− diffusion, and also sufficient free space for the sulfur reservoir and Li 2 S 2 /Li 2 S deposition. [Display omitted] • Co–C polyhedra reduced the formation of non-graphitic carbon in carbon aerogel. • Core-shell structures provided adequate accommodation capacity for sulfur species. • Multipoint Co–C polyhedron cores accelerated polysulfide redox reaction kinetics. • The S/Co-GC@GPCA cathode delivered outstanding cycling stability. [ABSTRACT FROM AUTHOR]

Flexible microwave absorption (MA) materials with high thermal conductivities and electric-thermal performances have promising applications in the wearable electronics and artificial intelligence fields. Herein, multifunctional and flexible ZnO/carbon cloth (CC@ZnO) films with effective MA performance were prepared using a typical hydrothermal method. The flexible CC@ZnO-3 film displays high reflection loss (R L) values of - 47.3 dB at 2.5 mm and broadest effective absorption bandwidth (EAB) of 4.0 GHz in the whole X band for the construction of 3D ZnO arrays and 2D CC matrix. Moreover, CC@ZnO-3 film was coated silver nanowires (AgNWs) solution to fabricate CC@ZnO/AgNWs/PVA (CAP) films with a highly conductively network. As a consequence, CC matrix and AgNWs conductive network contribute CAP with low voltages driven Joule heating performance, which ensure the functional integrity under extreme conditions. Therefore, our fabrications have potential applications in the fields of MA and the protection of wearable electronics. [ABSTRACT FROM AUTHOR]

• The structure of HCN can be controlled by the carbonization temperature. • HCN-800 shows an ultra-long cycle life and excellent electrochemical performance. • Achieved high areal mass loading through 3D printing technology. • LiCo 2 O 4 ||HCN-800 and Na 3 V 2 (PO 4) 3 ||HCN-800 full cells exhibits a stable cycle. Hollow nanostructures have shown great potential in energy storage and have attracted widespread attention. Here, we report a series of hollow carbon nanocage (HCN) by carbonizing ZIF-8@ZIF-67 core–shell precursor at different temperatures. The study found that when the carbonization temperature is 800 °C, HCN-800 has a good hollow structure, thin shell and large specific surface area, and contains abundant micropores and mesopores. When used as an anode material, even at a current density of 10.0 A g−1, it can still obtain reversible capacities of 236.1 mA h g−1 (5000 cycles, lithium ion batteries LIBs) and 111.7 mA h g−1 (10000 cycles, sodium ion batteries SIBs), showing excellent cycle stability and long cycle lifespan. And this outstanding ability can still be maintained under high areal mass loading. In addition, the lithium/sodium storage behavior was analyzed by CV kinetic analysis, ex-situ XPS and Raman tests. Benefiting from these advantages, HCN-800 can be prepared with higher areal mass loading by 3D printing and exhibit excellent lithium/sodium storage performance, which will bring broad application prospects for the development of high energy density secondary batteries. Finally, by using LiCoO 2 /Na 3 V 2 (PO 4) 3 cathode and HCN-800 anode to assemble a full cell to study the cycle performance. After 100 cycles at 0.1 A g−1 current density, the reversible capacity of 561.5 mA h g−1 (LIBs) and 164.7 mA h g−1 (SIBs) can be provided respectively, indicates that it has the potential of practical application. [ABSTRACT FROM AUTHOR]

SnP 0.94 nanodot electrocatalysts supported on porous hollow carbon aerogel matrix effectively manipulated electrochemical redox reaction kinetics of sulfur species. [Display omitted] • A synergistic SnP 0.94 @porous hollow carbon aerogel (SnP 0.94 @PHCA) was engineered. • The SnP 0.94 @PHCA could provide adequate accommodation capacity for sulfur species. • Experiment and DFT results confirmed strong adsorption/catalytic activity for LiPSs. • The S/SnP 0.94 @PHCA cathode exhibited an enhanced electrochemical performance. The realization of the high energy density of lithium-sulfur batteries (Li-S) has always been one of the targets pursued by researchers. However, the shuttling effect, dissolution of sulfur/lithium polysulfides (LiPSs), and sluggish redox kinetics in Li-S batteries restricted its long-term application and development. Herein, an advanced sulfur immobilizer composed of SnP 0.94 nanodot electrocatalysts@porous hollow carbon aerogel (SnP 0.94 @PHCA) was synthesized. As expected, the synergistic sulfur host can not only act as a good electrochemical interface but also provide adequate accommodation for active materials to alleviate the LiPS diffusion. More importantly, SnP 0.94 nanodot electrocatalysts supported on the conductive PHCA skeleton effectively expedited the conversion/redox reaction kinetics and also constructed a stronger adsorption system for LiPSs to inhibit the LiPS shuttling behavior. Correspondingly, the SnP 0.94 @PHCA composite endowed the sulfur cathode the outstanding specific capacity of 1017.8 mAh g−1 under a high sulfur loading (2.94 mg cm−2) at 0. 1 C, superior rate performance (579.8 mAh g−1 at 1 C), excellent cycling stability (the capacity decay rate of 0.13% per cycle at 0.5 C), and a high areal capacity of 6.9 mAh cm−2 under starved electrolyte conditions (8.6 μL mg s −1). This work opens up a new direction for constructing the electroactive hosts in Li-S batteries. [ABSTRACT FROM AUTHOR]

The ternary composite material ZnFe 2 O 4 @PANI-rGO with a core-shell structure and excellent electromagnetic absorption properties has been prepared by covalently modifying reducing graphene oxide with the binary magnetic material ZnFe 2 O 4 @PANI. The ternary composite material ZnFe 2 O 4 @PANI/rGO forms a " CO–NH ″ covalent bond between ZnFe 2 O 4 @PANI and rGO through hydrothermal routes and mechanical stirring. By comparing the two types of the connection method covalent and non-covalent bonds, it was surprised to find that formed by covalently connecting the binary ZnFe 2 O 4 @PANI material and rGO (C-ZPr) to obtain extremely excellent electromagnetic absorption performance. By adjusting the thickness from 1 mm to 4 mm, when the filler ratio is 20%, the minimum reflection loss (R Lmin) at 2.1 mm was as low as −49.99 dB at 17.28 GHz and the effective absorption bandwidth (R L < 10 dB) was almost 4.32 GHz. The introduction of covalent bonds becomes a bridge connecting magnetic materials and dielectric materials, adjusting electromagnetic parameters, enhancing reflection loss, and achieving impedance matching and improved electromagnetic absorbing performance. This preparation method is expected to provide new ideas for the preparation of high-performance absorbing materials in the future. [Display omitted] [ABSTRACT FROM AUTHOR]

Thermal management is a crucial issue for the reliability and life of the electronic devices. In this study, we successfully fabricated aluminum (Al) matrix composites with Cu networks (CNs) using a straightforward way. Graphite flakes (GFs) and CNs coated with graphene (CNs@Gr) were used to improve the performance of Al-matrix composites by hot-pressing method. There-dimensional (3D) CNs@Gr in the composites displayed an effective thermal transfer pathway in the matrix. The thermal conductivity (TC) of Al/GFs/CNs@Gr-5 composites (482.14 W/m·K) at a low Gr content, which has increased about 103.4% compared to pure Al. The synthesized CNs@Gr networks with continuous dendritic structure can serve as high-efficiency thermal transfer pathways to enhance heat dissipation through Gr layers, which reduced interfacial resistance for phonon scatterings. Furthermore, all fabricated composites displayed a lower coefficient of thermal expansion (less than 2.5 × 10−5) (CTE) than pure Al matrix (below 340℃). As a result, the construction of 3D networks in Al-matrix composites with high comprehensive performance makes them promising thermal management materials. [ABSTRACT FROM AUTHOR]

Different plants can be used to prepare nanoparticles. This is termed as green technology. It is one of the best ecofriendly and low-cost method for the preparation of nanoparticles which has no harmful effects. PbO nanoparticles were prepared by green method using leaf extract of Datura Sternum plants. The preparation of Lead oxide was confirmed by color change from colorless to yellowish brown. UV–Visible peak obtained at 250 nm and XRD study clarified the formation of PbO NPs. These PbO nanoparticles were then applied for the preparation of Nano Composite Polymer Membranes (nCPMs). PbO-PVC nCPMs were prepared based on polyvinyl chloride (PVC) polymer and PbO filler with the help of solution casting method, using cyclohexanone as a solvent. Different percentage (5–35%) of filler was used. The physiochemical parameters studied were viscosity, water uptake (WU), perpendicular swelling (DT) in deionized water, density, porosity (ε), morphology, ion adsorption capacity (IAC) and electrical conductivity (σ). The values of all these parameters except viscosity and conductivity were increased on increasing filler percentage. Viscosity of the nCPMs solution was decreased from 171 to 46.21. The conductivity of nCPMs was first increased upto 25% filler and then decreased. The deformation in PVC structure was increased on enhancing PbO amount. The values of Density, porosity, water uptake, DT and IAC were found in range 1.15–5.02, 0.50–0.87, 72.01–141.30, 0.012–0.11, and 3.13 × 107–8.60 × 107 respectively. Unlabelled Image • PbO nanoparticles were prepared by green method and was confirmed by color change from colorless to yellowish brown. The UV-Visible and XRD study clarified the formation of PbO NPs. • PbO-PVC nCPMs (Lead oxide-polyvinyl chloride nanocomposite polymer membrane were prepared using solution casting method and were investigated for physiochemical parameters. • The values of water uptake, perpendicular swelling, density, porosity, ion adsorption capacity, were increased except viscosity and conductivity on increasing filler percentages in the composites. • The deformation in PVC structure was increased on enhancing PbO amount. The values of Density, porosity, water uptake, DT and IAC were found in range 1.15 -5.02, 0.50- 0.87, 72.01-141.30, 0.012-0.11, and 3.13 x 107-8.60 x 107 respectively. [ABSTRACT FROM AUTHOR]

In this work, carbon dot decorated copper sulphide/carbon nanotubes (CuS@CD-CNTs) composite with a unique three-dimensional (3D) grape string-like structure was directly prepared via in situ hydrothermal process at the temperature of 180 °C for 12 h and applied for supercapacitors. The chemical composition and morphology were systematically tested by XRD, Raman, SEM and TEM characterization techniques. The as-prepared CuS@CD-CNTs composite brings out a novel 3D grape string-like structure, where the CuS spheres are distributed homogeneously with CNTs as a result of the addition of carbon dot. As the active material of pseudocapacitor electrode, the CuS@CD-CNTs composite delivers superior electrochemical properties with a decent specific capacitance of 736.1 F g−1 at the current density of 1 A g−1. Also, the CuS@CD-CNTs composite showed exceptional cycling stability, maintaining 92% retention after 5000 charge-discharge cycles. Such superior electrochemical properties owe to the collective contribution of CuS, CD and CNTs and 3D grape string-like architecture. The excellent electrochemical results above suggest that CuS@CD-CNTs composite has promising electrochemical energy storage application in supercapacitors. Image 1 • The CuS@CD-CNTs composite with a peculiar 3D grape string-like structure is synthesized by hydrothermal reaction. • The synergistic effect of CuS, CD and CNTs is beneficial for electrochemical performance. • The 3D CuS@CD-CNTs composite shows high capacitance and stable cyclic performance. [ABSTRACT FROM AUTHOR]

The impedance matching and high loss capabilities of composites with homogeneous distribution are limited owing to high addition and lack of structural design. Developing composites with heterogeneous distribution can achieve strong and wide electromagnetic (EM) wave absorption. However, challenges such as complex design and unclear absorption mechanisms still exist. Herein, a novel composite with a heterogeneous distribution gradient is successfully constructed via MOF derivatives Co@ nitrogen-doped carbon (Co@NC) anchored on carbon foam (CF) matrix (MDCF). Notably, the concentration of MOF can easily control the gradient structure. In particular, the morphologies of MOF derivatives on the surface of CF undergo a transition from the collapse of the inner layer to the integrity of the outer layer, accompanied by a continuous reduction in the size of Co nanoparticles. Correspondingly, enhanced interface polarization from the core-shell of Co@NC and good impedance matching of MDCF can be obtained. The optimized MDCF exhibits the minimum reflection loss of -68.18 dB at 2.01 mm and effective absorption bandwidth covering the entire X-band. Moreover, MDCF exhibits lightweight characteristics, excellent compressive strength, and low radar cross-section reduction. This work highlights the immense potential of composites with heterogeneous distribution for achieving high-performance EM wave absorption., (© 2024 Wiley‐VCH GmbH.)

Sensitive and rapid identification of volatile organic compounds (VOCs) at ppm level with complex composition is vital in various fields ranging from respiratory diagnosis to environmental safety. Herein, we demonstrate a SERS gas sensor with size-selective and multiplexed identification capabilities for VOCs by executing the pre-enrichment strategy. In particular, the macro-mesoporous structure of graphene aerogel and micropores of metal-organic frameworks (MOFs) significantly improved the enrichment capacity (1.68 mmol/g for toluene) of various VOCs near the plasmonic hotspots. On the other hand, molecular MOFs-based filters with different pore sizes could be realized by adjusting the ligands to exclude undesired interfering molecules in various detection environments. Combining these merits, graphene/AuNPs@ZIF-8 aerogel gas sensor exhibited outstanding label-free sensitivity (up to 0.1 ppm toluene) and high stability (RSD=14.8%, after 45 days storage at room temperature for 10 cycles) and allowed simultaneous identification of multiple VOCs in a single SERS measurement with high accuracy (error < 7.2%). We visualize that this work will tackle the dilemma between sensitivity and detection efficiency of gas sensors and will inspire the design of next-generation SERS technology for selective and multiplexed detection of VOCs., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Two-dimensional transition metal carbon/nitrides (MXenes) are promising candidates to revolutionize next-generation wearable sensors as high-performance surface-enhanced Raman scattering (SERS) substrates. However, low sensitivity of pure MXene nanosheets and weak binding force or uncontrolled in situ growth of plasmonic nanoparticles on hybrid MXene composites limit their progress toward universal and reliable sensors. Herein, we designed and manufactured a highly sensitive, structurally stable wearable SERS sensor by in situ fabrication of plasmonic nanostructures on the flexible TiVC membranes via the maximization of chemically reducing sites using alkaline treatment. DFT calculations and experimental characterization demonstrated that the hydroxyl functional groups on the surface of MXenes can facilitate the reduction of metal precursors and the nucleation of gold nanoparticles (AuNPs) and can be covalently attached to AuNPs. Thus, the fabricated flexible TiVC-OH-Au sensor satisfied the rigorous mechanical requirements for wearable sensors. In addition, combining the electromagnetic (EM) enhancement from dense AuNPs formed by the activation of nucleation sites and charge transfer (CT) between target molecule and substrate induced by the abundant DOS near the Fermi level of TiVC, the fabricated sensor exhibits ultrasensitivity, long-term stability, good signal repeatability, and excellent mechanical durability. Moreover, the proof-of-concept application of the wearable SERS sensor in sweat sensing was demonstrated to monitor the content of nicotine, methotrexate, nikethamide, and 6-acetylmorphine in sweat at the molecular level, which was an important step toward the universality and practicality of the wearable sensing technology.

High sensitivity, good signal repeatability, and facile fabrication of flexible surface enhanced Raman scattering (SERS) substrates are common pursuits of researchers for the detection of probe molecules in a complex environment. However, fragile adhesion between the noble-metal nanoparticles and substrate material, low selectivity, and complex fabrication process on a large scale limit SERS technology for wide-ranging applications. Herein, we propose a scalable and cost-effective strategy to a fabricate sensitive and mechanically stable flexible Ti 3 C 2 T x MXene@graphene oxide/Au nanoclusters (MG/AuNCs) fiber SERS substrate from wet spinning and subsequent in situ reduction processes. The use of MG fiber provides good flexibility (114 MPa) and charge transfer enhancement (chemical mechanism, CM) for a SERS sensor and allows further in situ growth of AuNCs on its surface to build highly sensitive hot spots (electromagnetic mechanism, EM), promoting the durability and SERS performance of the substrate in complex environments. Therefore, the formed flexible MG/AuNCs-1 fiber exhibits a low detection limit of 1 × 10 -11 M with a 2.01 × 10 9 enhancement factor (EF exp ), signal repeatability (RSD = 9.80%), and time retention (remains 75% after 90 days of storage) for R6G molecules. Furthermore, the l-cysteine-modified MG/AuNCs-1 fiber realized the trace and selective detection of trinitrotoluene (TNT) molecules (0.1 μM) via Meisenheimer complex formation, even by sampling the TNT molecules at a fingerprint or sample bag. These findings fill the gap in the large-scale fabrication of high-performance 2D materials/precious-metal particle composite SERS substrates, with the expectation of pushing flexible SERS sensors toward wider applications.

Superpixel decomposition could reconstruct an image through meaningful fragments to extract regional features, thus boosting the performance of advanced computer vision tasks. To further optimize the computational efficiency as well as segmentation quality, a novel framework is proposed to generate superpixels from the perspective of hybridizing two existing linear clustering frameworks. Instead of conventional grid sampling seeds for region clustering, a fast convergence strategy is first introduced to center the final superpixel clusters, which is based on an accelerated convergence strategy. Superpixels are then generated from a center-fixed online average clustering, which adopts region growing to label all pixels in an efficient one-pass manner. The experiments verify that the integration of this two-step implementation could generate a synergistic effect and that it becomes more well-rounded than each single method. Compared with other state-of-the-art superpixel algorithms, the proposed framework achieves a comparable overall performance in terms of segmentation accuracy, spatial compactness and running efficiency; moreover, an application on image segmentation verifies its facilitation for traffic scene analysis.

Based on the increasing application requirements for the efficient adsorption of wastewater pollutants, graphene oxide-carbon nanotube/activated carbon (GO-CNT/AC) composites are constructed from the optimal microstructure matching of GO, CNTs, and AC materials by solution impregnation and freeze-drying methods. Three-dimensional structures with nano-micro hierarchical pores are established, with GO and CNTs uniformly dispersed on the AC surface, effectively restrain the agglomeration. The added CNTs played a "spring" role, supporting the gap between the GO sheets and AC matrix. Meanwhile, stable links are formed between GO, CNTs, and AC, realizing the synergistic matching of the microstructure, which provides abundant active absorption sites beneficial for improving the adsorption performance. The influences of the CNT contents, adsorbent amounts, methylene blue (MB) concentrations, and pH values on the adsorption property of GO-CNT/AC composites are systematically investigated. The results show that when the pH value of the MB solution is 13, the CNT concentration is 3 mg/mL and the MB concentration is 200 mg/L, the adsorption property of the composite is the best, with an adsorption capacity of 190.8 mg/g and a removal percentage of 95.4%. Compared with the raw AC, the adsorption capacity and removal percentage of the composites are increased by 73.9% and 72.8%, respectively. The GO-CNT/AC composites exhibit excellent cyclic adsorption performance, with a cyclic stability of 91.8% after six rounds of adsorption-desorption cycles. The kinetic analysis shows that the adsorption process conforms to the PSO kinetic model. By fitting of the IPD model, the adsorption mechanisms of the GO-CNT/AC composites are divided into two adsorption stages and described respectively. This study provides a new way to achieve highly efficient adsorption of pollutants in wastewater.

In view of the good adsorption properties of graphene and carbon foam, they were combined to achieve the optimal matching of microstructures. Taking mesophase pitch as a raw material, pitch-based carbon foam was prepared by the self-foaming method. Graphene gel was prepared as the second phase to composite with the carbon foam matrix; graphene-modified, pitch-based carbon foam composites were finally obtained. Graphene gel was dispersed in the rich pore structure of carbon foam to improve its agglomeration and the porosity, and the active sites of the composite were further increased; the adsorption properties and mechanical properties of the composites were also significantly improved. The microstructure and morphology of the composites were studied by SEM, XRD and Raman spectroscopy; the compressive property and porosity were also tested. Methylene blue (MB) solution was used to simulate a dye solution for the adsorption test, and the influence of the composite properties and MB solution on the adsorption property was studied. Results showed that the compressive strength of the composite was 13.5 MPa, increased by 53.41%, and the porosity was 58.14%, increased by 24.15%, when compared to raw carbon foam. When the mass of the adsorbent was 150 mg, the initial concentration of the MB solution was 5 mg/L, and the pH value of the MB solution was 11; the graphene-modified carbon foam composites showed the best adsorption effect, with an adsorption rate of 96.3% and an adsorption capacity of 144.45 mg/g. Compared with the raw carbon foam, the adsorption rate and adsorption capacity of the composites were increased by 158.18% and 93.50%, respectively.

The graphitization degree is of great importance for determining the electromagnetic (EM) wave attenuation loss behavior. The conductive loss is considered to be the mechanism resulting from tailoring the graphitization degree. There is a lack of in-depth research on the dipole polarization caused by defects and functional groups and the interface polarization caused by graphite/amorphous carbon. Herein, lightweight carbon foam (CF) bulk derived from mesophase pitch was prepared to clarify the effect of the graphitization degree systematically. The results demonstrate that with an increase graphitization degree, the interfacial polarization improves and dipole polarization decreases. The synergistic effect of conduction loss and dipole and interfacial polarization dominates the impedance matching and further changes the EM loss behavior of CFs. Particularly, the minimum reflection loss is - 16.69 dB and effective absorption bandwidth is 3.63 GHz, the EM interference shielding effectiveness attains 35.13 dB and the compressive strength is up to 11.73 MPa when the optimal graphitization degree is achieved. Therefore, this work elucidates the effect of the interface polarization of graphite/amorphous carbon, thus providing a valuable insight into the design of advanced carbon-based materials for EM wave absorption and shielding., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Inc. All rights reserved.)