Carbon-based Composites Research Articles

Fe3O4 Nanoparticles Embedded into Pyridinic-N-Rich Carbon Nanohoneycomb with Strong dx2-Pz Orbital Hybridization for High-Performance Electromagnetic Wave Absorption.

Carbon-based magnetic nanocomposites as promising lightweight electromagnetic wave (EMW) absorbents are expected to address critical issues caused by electromagnetic pollution. Herein, Fe3O4 nanoparticles embedded into a 3D N-rich porous carbon nanohoneycomb (Fe3O4@NC) were developed via the pyrolysis of an in-situ-polymerized compound of m-phenylenediamine initiated by FeCl2 in the presence of NaCl crystals as templates. Results demonstrate that Fe3O4@NC features highly dispersed Fe3O4 nanoparticles into an ultrahigh specific pyridinic-N doping carbon matrix, resulting in excellent impedance matching characteristics and electromagnetic wave absorbing capability with the biggest effective absorption bandwidth (EAB) of up to 7.1 GHz and the minimum reflective loss (RLmin) of up to -65.5 dB in the thin thickness of 2.5 and 2.3 mm, respectively, which also outperforms the majority of carbon-based absorbers reported. Meanwhile, its high absorption performance is further demonstrated by an ethylene propylene diene monomer wave absorbing patch filled with 8.0 wt % Fe3O4@NC, which can completely shield a 5G signal in a mobile phone. In addition, theory calculation reveals that there is a strongest dx2-Pz orbital hybridization interaction between Fe3O4 clusters and pyridinic-N dopants in the carbon network, compared with other kinds of N dopants, which can not only generate more dipoles of carbon networks but also increase net magnetic moments of Fe3O4, thereby leading to a coupling effect of efficient dielectric and magnetic losses. This work provides new insights into the precise design and synthesis of carbon-based magnetic composites with specific interface interactions and morphological effects for high-efficiency EMW absorption materials.

N-doped CNTs/CoNi nanochains-carbon hollow microspheres multi-level multi-scale heterogeneous interface structures and microwave absorption properties

Constructing multi-level multi-scale heterogeneous interfaces in magnetic carbon-based composites remains a formidable challenge, requiring rational material combinations to effectively balance dielectric and magnetic losses for achieving high strength and wide frequency wave absorption. Electromagnetic wave (EMW) absorbing materials consisted of cobalt-nickel (CoNi) magnetic nanochain, nitrogen-doped carbon nanotubes (NCNTs) and hollow carbon microspheres were prepared by hydrothermal method without external magnetic field. These composites possessed a unique multi-level multi-scale heterogeneous interface structure that is highly advantageous for efficient absorption of EMWs. The CoNi nanoparticles were self-assembled into uniformly distributed and randomly oriented magnetic nanochains, which were further reassembled with NCNTs and hollow carbon microspheres to form heterogeneous interface structures resembling a rose, chrysanthemum, hedgehog ball, and bauhinia tree. Due to the high-density interface enhancing the loss ability of interface polarization, as well as the higher saturation magnetization, coercivity, and wave absorption ability of the magnetic nanochains compared to the magnetic nanoparticles themselves, the minimum reflection loss achieved is −66.86 dB, and the effective absorption bandwidth achieved is 5.01 GHz, at a content as low as 11 wt%. This study provides a new idea for generating nanochains without magnetic fields and constructing multi-level and multi-scale heterogeneous interface structures to achieve strong absorption and wide effective absorption bandwidth (EAB).

Carbon Fiber-Based Vitrimer Composites: A Path toward Current Research That Is High-Performing, Useful, and Sustainable.

In the polymeric material industry, thermosets and related composites have played a substantial role in the production of rubber and plastics. One important subset of these is thermoset composites with carbon reinforcement. The incorporation of carbon fillers and fibers gives polymeric materials improved electrical and mechanical properties, among other benefits. However, the covalently crosslinked network of thermosets presents significant challenges for recycling and reprocessing because of its intractable nature. The introduction of vitrimer materials opens a new avenue to produce biodegradable and recyclable thermosets. Carbon-reinforced vitrimer composites are pursued for high-performance, long-lasting materials with attractive physical properties, the ability to be recycled and processed, and other features that respond uniquely to stimuli. The development of carbon-reinforced vitrimer composites over the last few years is summarized in this article. First, an overview of vitrimers and the methods used to prepare carbon fiber-reinforced vitrimer composites is provided. Because of the vitrimer nature of such composites, reprocessing, healing, and recycling are viable ways to greatly extend their service life; these approaches are thoroughly explained and summarized. The conclusion is our prediction for developing carbon-based vitrimer composites.

Evaluation of the Modal Parameters of a Unidirectional Carbon-Based Composite Structure Using the Influential Factor of Static Loading.

Static loading can significantly alter the dynamics of unidirectional carbon-based composites (UCBCs), with modal parameters varying depending on the orientation of the carbon fibers. In this study, the sensitivity of modal parameters of UCBC structures under uniaxial static loading was investigated. The theoretical static load influential factor was derived from a linearized UCBC model and corresponded to the transformed decoupled response over the mass-normalized static load. Three rectangular UCBC specimens (carbon fiber orientation of 0°, 45°, and 90°) were prepared under fixed-fixed boundary conditions using a jig fixture. Uniaxial static loads between 0 N and 1000 N were applied, and the first three modes of the UCBC specimens were analyzed. An isotropic SUS304 specimen was used as a reference. The linearization assumption about the UCBC structure was preliminarily validated with the Modal Assurance Criterion (MAC). A high influential factor was found for the UCBC specimen when carbon fibers were aligned with the static load direction at the first two resonance frequencies. Therefore, the proposed influential factor is an efficient indicator for determining the sensitivity of the dynamic response of a UCBC structure over a static load case. The variations in the influential factors for the UCBC specimens were more pronounced than for the isotropic specimens.

Thermal shock resistance of carbon-based composites reinforced by HfC nanowires under extreme conditions

Lightweight composites with excellent thermal shock performance exhibit significant potential for thermal structural components. Herein, HfC nanowires modified carbon/carbon (HfCNWs-C/C) composites are fabricated, establishing a three-dimensional network within the matrix. The microstructure of the composites before and after thermal shock cycles were characterized by SEM, XRD and TEM. Additionally, the flexural strength with varied thermal shock were analyzed, which were initially increasing before subsequently decreasing with the number of thermal shock cycles under Ar atmosphere, exhibiting thermal shock strengthening phenomena. While within oxy-acetylene system, the strength of HfCNWs-C/C exhibit an increasement of 75 % compared with C/C after ablation for 6 cycles, which can be attributed to the sintering and the generation of molten film of partial HfO2 phases that can mitigates oxidation of the matrix, but still lead to a declining trend in the strength following ablative thermal cycles.

Multi-interface spatial star-like MoC/Co/C composites toward enhanced electromagnetic wave absorption properties

Interfacial engineering and morphology design are two popular strategies to strengthen the performance of carbon-based composites as electromagnetic wave absorbing materials (EWAMs). Herein, we integrate their advantages simultaneously in ternary MoC/Co/C composites (SMCCs). On one hand, highly dispersed MoC and Co nanoparticles create abundant heterogeneous interfaces, and on the other hand, the spatial star-like carbon skeletons derived from ZnCo-MOF also bring significant structure contribution to EM energy consumption. EM measurement reveals that the pyrolysis temperature greatly impacts EM properties of SMCCs. After blending with paraffin (organic binder), the mixture that involves SMCC-800 (pyrolyzed at 800 °C) may have both good impedance matching degree and powerful EM attenuation ability. As a result, SMCC-800/paraffin displays excellent EM absorption performance, including strong reflection loss intensity down to −67.3 dB at 16.2 GHz (thickness: 1.8 mm) and broad response bandwidth of 6.0 GHz (12.0–18.0 GHz, thickness: 2.0 mm) less than −10.0 dB, which outdo the performance of many composites with similar chemical composition ever reported. The EM absorption mechanism of SMCC-800/paraffin is comprehensively illustrated through the investigation on EM properties of the mixtures with various control samples.

N-Containing Porous Carbon-Based MnO Composites as Anode with High Capacity and Stability for Lithium-Ion Batteries.

MnO has attracted much attention as the anode for Li-ion batteries (LIBs) owing to its high specific capacity. However, the low conductivity limited its large application. An effective solution to solve this problem is carbon coating. Biomass carbon materials have aroused much interest for being low-cost and rich in functional groups and hetero atoms. This work designs porous N-containing MnO composites based on the chemical-activated tremella using a self-templated method. The tremella, after activation, could offer more active sites for carbon to coordinate with the Mn ions. And the as-prepared composites could also inherit the special porous nanostructures of the tremella, which is beneficial for Li+ transfer. Moreover, the pyrrolic/pyridinic N from the tremella can further improve the conductivity and the electrolyte wettability of the composites. Finally, the composites show a high reversible specific capacity of 1000 mAh g-1 with 98% capacity retention after 200 cycles at 100 mA g-1. They also displayed excellent long-cycle performance with 99% capacity retention (relative to the capacity second cycle) after long 1000 cycles under high current density, which is higher than in most reported transition metal oxide anodes. Above all, this study put forward an efficient and convenient strategy based on the low-cost biomass to construct N-containing porous composite anodes with a fast Li+ diffusion rate, high electronic conductivity, and outstanding structure stability.

Enhancing X-band microwave absorption properties with nickel ferrite and carbon-based composites

The present study focuses on synthesizing a composite material comprising of nickel ferrite and carbon derived from cotton, to exhibit exceptional microwave absorption capabilities over a wide frequency range. By adopting a mechanical alloy method, the microwave-absorbing composite is developed. The microwave absorption characteristics of the developed composites are further unearthly in terms of their permittivity and permeability. Combining magnetic and dielectric phases produces better eddy current loss and polarization, which are primarily responsible for absorption characteristics. The developed composites are cast into rectangular pallets to evaluate microwave absorption characteristics and examined using a vector network analyzer within the 8.2–12.4 GHz frequency range. With a pallet thickness of 2.55 mm, the entire X-band frequency is effectively covered, yielding a remarkable minimum reflection loss of −20.46 dB at 10.01 GHz. The current work's findings, owing to the synergistic combination of nickel ferrite and carbonized carbon provide a practical approach for developing a hybrid material with remarkable electromagnetic performance.

Fabrication of bimetallic-doped materials derived from two polymorphic Ni-Mo-based coordination polymers for enhanced dye removal and gaseous iodine capture

Two polymorphic Ni–Mo-based coordination polymers (CPs) based on the ligand N,N′-bis(4-pyridinecarboxamide)-1,2-cyclohexane (4-bpah) were created using hydrothermal synthesis. Each of these CPs (denoted as Ni–Mo-1 and Ni–Mo-2) has the similar main framework [Ni(4-bpah)2(Mo2O7)], but they each show different crystalline phases with different 2D grid windows. Moreover, the Ni–Mo-based CP-derived carbon-based composites (C–Ni–Mo-X-Y, X = 1 or 2 and Y = 400, 450, or 500) were prepared by thermal cracking and “low-temperature” calcination below 500 °C using two CPs as precursors. The results show that the Ni–Mo-based CP-derived carbon-based composites prepared at different temperatures exhibit irregular morphologies with different micron-sized or nano-sized loose structures and chemical compositions. Furthermore, the dye and gas iodine adsorption properties of the C–Ni–Mo-X-Y composites were investigated in detail.

Publisher's Note: “Phase change-related thermal property characterization and enhancement in carbon-based organic phase change composites” [Appl. Phys. Rev. 11, 021322 (2024)

Publisher's Note: “Phase change-related thermal property characterization and enhancement in carbon-based organic phase change composites” [Appl. Phys. Rev. <b>11</b>, 021322 (2024)

SiCnws/CNTs/Cf-C/SiOC composites with multi-scale lossy phases for simultaneous electromagnetic wave absorption and thermal insulation

Carbon fiber reinforced carbon-based composites are considered to be an ideal lightweight material with exceptional high-temperature mechanical performance. Nevertheless, their high conductivity result in a strong reflection rather than absorption of electromagnetic wave (EMW) for the stealth application. To address this challenge, a novel carbon-based composite made of multi-scale lossy phases (Carbon nanotubes (CNTs), SiC nanowires (SiCnws), and Carbon fiber (Cf)) and impedance matching phase (SiOC ceramic) was fabricated by the precursor-derived method. The prepared SiCnws/CNTs/Cf-C/SiOC (SCC-CS) composites exhibit an effective absorption (EAB) of 2.4 GHz at a thickness of 1.9 mm and a minimum reflection loss (RLmin) of −58.44 dB (99% absorption) in the X band. The EMW absorption of the composite is attributed to the multiple loss mechanisms and favorable impedance matching with free space, caused by the multi-conductive phase and SiOC in the composite. In addition, the fabricated composites also have thermal insulation properties and can effectively achieve radar cross-sectional (RCS) reduction, which are promising aerospace composites with the integration of structure and function.

Structural optimization and electrocatalytic hydrogen production performance of carbon-based composites: A mini-review

The energy demand has increased significantly in recent years and it is urgent to develop a renewable energy system that is highly efficient and non-noble metal-based. Hydrogen energy is an environmentally friendly energy source with abundant resources, which can be used to solve the problem of high energy demand without greenhouse gas emissions. However, the development of catalysts for hydrogen production technology by electrolysis of water is slow, mainly due to the complexity of the electrolysis hydrogen generation process, low hydrogen production efficiency, weak electrode material activity and high cost. Among the non-noble metal-based catalysts, carbon-based materials have high conductivity, tunable chemical bonding, and easily modified morphology, making them beneficial to achieving efficient hydrogen production, though pure carbon composites suffer from few surface-active sites and unmoderated hydrogen bonding energy, which need to be further optimized. The principle of electrocatalytic hydrogen production from the perspectives of reaction thermodynamics and kinetics is analyzed and discussed in this paper. Thermodynamics of electrocatalytic hydrogen production is reflected by the Gibbs free energy of hydrogen adsorption (ΔGH*) and electrode potential (E). Reaction kinetics of the electrocatalytic hydrogen production process are reflected by overpotential, Tafel slope and exchange current density. Structural optimization methods of carbon-based composite materials and hydrogen production performance after structural optimization are also summarized. Structural optimization methods of carbon-based composite materials mainly include introducing active sites, improving conductivity, increasing specific surface area and introducing self-supporting materials. Finally, prospects are proposed for the development direction and existing problems of electrocatalytic hydrogen production performance of carbon-based composites.

Advancing energy solutions: Carbon-based cementitious composites in energy storage and harvesting

The rapid progress of smart and sustainable cities has led to an increased demand for construction materials that possess functional capabilities in energy storage and harvesting. In light of this, a comprehensive literature review is conducted in this study to investigate the multifunctional properties exhibited by carbon-based cementitious materials. Specifically, the piezoelectric, thermoelectric, tensile, compressive, and flexural behaviors of carbon fiber (CF), graphene, graphite powder (GP), and carbon nanotubes (CNTs) are thoroughly examined through multi-scale research approaches. The electrical conductivity and mechanical properties of these carbon-based additives are analyzed in relation to their molecular structures. Evaluation results reveal that CNTs-based cementitious composites demonstrate 160 %–269 % superior multifunctional performance compared to their CF-based counterparts. Furthermore, the feasibility of potential applications of carbon-based cementitious composites in concrete construction is extensively discussed, encompassing diverse areas such as thermoelectric energy harvesting, intelligent structural adjustment, cathodic protection systems, snow and ice melting, electromagnetic shielding, and structural health monitoring. The research outcomes presented in this study offer a systematic evaluation of a wide range of carbon-based cementitious materials, providing valuable guidelines and recommendations for engineers.

Phase change-related thermal property characterization and enhancement in carbon-based organic phase change composites

By utilizing the significant amount of energy absorbed and released during their phase transitions, phase change materials (PCMs) can capture and store thermal energy to fill gaps between supply and demand. Due to their many favorable properties, organic PCMs have gained attention in a wide range of applications. Nevertheless, their inherent low thermal conductivity has limited the direct use of organic PCMs in thermal energy storage (TES). Extensive research has been conducted on enhancing organic PCM thermal conductivity by incorporating high thermal conductivity materials. Owing to their high thermal conductivity and low density, carbon-based materials have been extensively used for thermal conductivity enhancement in phase change composites (PCCs). Carbon-based organic PCCs, which incorporate highly thermally conductive carbon allotropes and their direct chemical derivatives with organic PCMs, are a group of diverse PCCs with highly promising potential for TES applications. Adequate latent heat and shape stability performances are crucial to the success of the applicational performances of these PCCs. Much empirical research has pushed efforts to enhance these phase change properties, yet a logical understanding of these enhancement efforts based on the thermodynamics and intermolecular interactions of carbon-based organic PCCs has been elusive. In particular, the effect of characterization methods on the evaluation of phase change properties has been largely understudied. This review strives to provide novel physical and chemical insights into latent heat and shape stabilization evaluation processes and enhancement efforts in carbon-based organic PCCs through a detailed review and analysis of recent literature. The review provides an unprecedented comprehension of newly developed PCCs that challenge the traditional understanding that the latent heat of PCCs cannot exceed that of its base PCM. Efforts on phase change property enhancement driven by these new insights have the potential for carbon-based organic PCCs to succeed in a variety of TES applications, including solar-thermal harvesting, thermal management of batteries and electronics, thermoregulating textiles, and infrared stealth and infrared responsive materials.

Predicting the compressive strength of carbon-enhanced cementitious composites using two-dimensional convolutional neural networks

This study addresses the limitations of traditional statistical methods and artificial neural networks (ANNs) in extracting relevant features from carbon-based cementitious composites to assess their dynamic behaviors under various environmental conditions. However, previous deep-learning methods were limited in making efficient predictions utilizing multiple factors. These shortcomings are not appropriate for predicting the properties of cement composed of various elements. In this study, these elements were converted into image form to handle efficiently the multiple factors that consist of cement, and the prediction was performed using a convolutional neural network (CNN)-based model. The concentration range of multiwalled carbon nanotubes (MWCNTs) used was 0.25 wt % to 1.0 wt %. Additionally, the specimens utilized were 50×50×50mm3 in size, and a total of 532 pieces of data were employed. Based on mean absolute error (MAE), performance was improved by approximately 25 % with ANN (MAE = 3.89) and 7.2 % with random forest (MAE = 3.14) compared with the proposed model (MAE = 2.92). The findings of this study are a novel and practical approach for predicting the mechanical properties of cementitious composites, enabling reverse application to optimize mixing ratios for CNT cement composites, and streamlining fabrication.

Co-Doped Porous Carbon/Carbon Nanotube Heterostructures Derived from ZIF-L@ZIF-67 for Efficient Microwave Absorption.

Carbon-based magnetic metal composites derived from metal-organic frameworks (MOFs) are promising materials for the preparation of broadband microwave absorbers. In this work, the leaf-like co-doped porous carbon/carbon nanotube heterostructure was obtained using ZIF-L@ZIF-67 as precursor. The number of carbon nanotubes can be controlled by varying the amount of ZIF-67, thus regulating the dielectric constant of the sample. An optimum reflection loss of -42.2 dB is attained when ZIF-67 is added at 2 mmol. An effective absorption bandwidth (EAB) of 4.8 GHz is achieved with a thickness of 2.2 mm and a filler weight of 12%. The excellent microwave absorption (MA) ability is generated from the mesopore structure, uniform heterogeneous interfaces, and high conduction loss. The work offers useful guidelines to devise and prepare such nanostructured materials for MA materials.

Polyimide Enables Carbon-Based Conductive Polymer Composites with High Working Temperature for Deicing Application

Polyimide Enables Carbon-Based Conductive Polymer Composites with High Working Temperature for Deicing Application

Enhanced adsorption capacity of phosphoric acid-modified montmorillonite clay and ground coffee waste-derived carbon-based functional composite beads for the effective removal of methylene blue

Clays, valued for their versatility, serve as economical adsorbents. Recent studies show that physical, thermal, and chemical modifications can enhance their adsorption capacity. In this study, the synthesis of a functional bead comprising phosphoric acid-modified montmorillonite (PMMT) and coffee waste carbon (CWC) and its application for the efficient adsorption of methylene blue (MeB) dye is investigated. A highly flexible and low-cost phyllosilicate, montmorillonite clay, MMT was treated with phosphoric acid to enhance the ionic density, composited with CWC, resulting in improved surface properties thereafter was transformed into easily recoverable bead form through subsequent cross-linking steps. These functional composite beads were characterized using various characterization techniques. As a result, the existing tetrahedral sheets possessed by the MMT having weak bonds between the layers are improved in a way that they can allow molecule exchange for the efficient enhancement of the adsorption capacity of the composite material. Moreover, after the necessary modifications, the adsorbent was found to be mechanically stable, inhibiting secondary pollutions from the use in powder forms while allowing the interlayers favorable for not just cationic but also anionic exchange whilst increasing the specific surface area and pore volume. The surface area was enhanced to 9.93 m2 /g. Following this, maximum adsorption capacity of 489.9 mg/g was attained showing a superior removal efficiency for methylene blue dye (>80%). The adsorption equilibrium was analyzed using Freundlich and Langmuir models. The adsorption mechanism aligns with the Langmuir model which encompasses a monolayer adsorption. All in all, this study is anticipated to play a crucial role in the search for adsorbents with multiple functionalities and good structural stability during and after use.

Carbon-Based Composites for Oxygen Evolution Reaction Electrocatalysts: Design, Fabrication, and Application.

The four-electron oxidation process of the oxygen evolution reaction (OER) highly influences the performance of many green energy storage and conversion devices due to its sluggish kinetics. The fabrication of cost-effective OER electrocatalysts via a facile and green method is, hence, highly desirable. This review summarizes and discusses the recent progress in creating carbon-based materials for alkaline OER. The contents mainly focus on the design, fabrication, and application of carbon-based materials for alkaline OER, including metal-free carbon materials, carbon-based supported composites, and carbon-based material core-shell hybrids. The work presents references and suggestions for the rational design of highly efficient carbon-based OER materials.

Preparation and properties of activated carbon-based Na3PO4 composites for low-temperature thermochemical heat storage

With the advantages of low heat storage temperature, high heat storage density, and a low price, Na3PO4 has been proposed as a thermochemical heat storage candidate material for use in solar low-temperature heat storage engineering applications. However, the application of pure Na3PO4 is limited due to its propensity for agglomeration. In this study, activated carbon-based Na3PO4 (R-AC@Na3PO4) composites with mass fractions of 30 %, 50 %, and 80 % were synthesized by melt impregnation method using activated carbon as the porous matrix. The morphology and structure of the composites were characterized, and their heat storage performances were investigated. The hydration experiments were carried out in a constant temperature and humidity chamber and dehydration experiments were carried out in thermogravimetric analysis and differential scanning calorimetry simultaneously. The results showed that at 30 °C, 60 % relative humidity, the hydration equilibrium time for the composites were only 30 %–40 % of the pure material. Meanwhile, at a mass fraction of 80 %, material's volumetric heat storage can reach 1793 J·cm−3 without agglomeration, and the performance was stable after 20 cyclic tests. This study provides a reference for the research and development of low-temperature thermochemical heat storage materials and offers more possibilities for R-AC@Na3PO4 composites in future engineering applications.