Search Results (198)

Graphene oxide (GO) aerogels were discovered as lightweight, highly porous materials with exceptional mechanical, electrical, and thermal properties. These properties make them suitable for a wide range of advanced applications. This paper discusses GO aerogel synthesis processes, characterization, mechanical properties, applications, and future directions. The synthesis methods discussed include hydrothermal reduction, chemical reduction, crosslinking methods, and 3D printing, with major emphasis on their effects on the aerogel’s structural and functional attributes. A detailed analysis of mechanical characterization techniques is elaborated upon, along with highlighting the effects of parameters such as porosity, crosslinking, and graphene concentration on mechanical strength, elasticity, and stability. Research has been carried out to find GO aerogel applications in various sectors, such as energy storage, environmental remediation, sensors, and thermal management, showcasing their versatility and potential. Additionally, the combination of nanoparticles and doping strategies to improve specific properties is addressed. The review concludes by identifying current challenges in scalability, brittleness, and property optimization and proposes future directions for synthesis innovations. This work will be helpful for researchers and engineers exploring new possibilities for GO aerogels in both academic and industrial areas. Full article

Lithium–sulfur batteries (LSBs), possessing excellent theoretical capacities, advanced theoretical energy densities, low cost, and nontoxicity, are one of the most promising energy storage battery systems. However, some issues, including poor conductivity of elemental S, the “shuttle effect” of high-order lithium polysulfides (LiPSs), and sluggish reaction kinetics, hinder the commercialization of LSBs. To solve these problems, various carbon-based aerogels with developed surface morphology, tunable pores, and electrical conductivity have been examined for immobilizing sulfur, mitigating its volume variation and enhancing its electrochemical kinetics. In this paper, an extensive generalization about the effective preparation methods of carbon-based aerogels comprising the combined method of carbonization with the gelation of precursors and drying processes (ambient pressure drying, freeze-drying, and supercritical drying) is proposed. And we summarize various carbon carbon-based aerogels, mainly including graphene aerogels (Gas) and carbon nanofiber (CNF) and carbon nanotube (CNT) aerogels as cathodes, separators, and interlayers in LSBs. In addition, the mechanism of action of carbon-based aerogels in LSBs is described. Finally, we conclude with an outlook section to provide some insights into the application of carbon-based aerogels in electrochemical energy storage devices. Based on the discussion and proposed recommendations, we provide more approaches on nanomaterials in high-performance liquid or state LSBs with high electrochemical performance in the future. Full article

Despite their outstanding thermal insulation and ultralight structure, silica aerogels suffer from inherent mechanical fragility, making the investigation of their mechanical behavior crucial for expanding their practical utility in advanced applications. To enhance their mechanical performance, this study introduces a dual-phase reinforcement strategy by anisotropically incorporating carbon nanotubes (CNTs) and graphene oxide (GO) sheets into the aerogel matrix. Using molecular dynamic simulations, we systematically investigate the tensile behavior and pore structure evolution of these hetero-structured composites. The results reveal a non-monotonic dependence of tensile strength on loading ratio, distinguishing three strain-dependent reinforcement regimes. High loading content (11.1%) significantly improves strength under low strain (0–26%), whereas low loading levels (1.8%) are more effective at preserving structural integrity under large strain (44–50%). Moderate loading (5.1%) yields balanced performance in intermediate regimes. While increasing carbon content reduces initial pore size by partially filling the framework, tensile deformation leads to interfacial debonding and the formation of larger pores due to CNT–GO hybrid structure interactions. This work elucidates a dual reinforcement mechanism—physical pore confinement and interfacial coupling—highlighting the critical role of nanostructure geometry in tuning strain-specific mechanical responses. The findings provide mechanistic insights into anisotropic nanocomposite behavior and offer guidance for designing robust porous materials for structural and functional applications. Full article

Advancements in thermoregulating textiles have been propelled by innovations in nanotechnology, composite materials, and smart fiber engineering. This article reviews recent scholarly papers on experimental passive and active thermoregulating textiles to present the latest advancements in these fabrics, their mechanisms of thermoregulation, and their feasibility for use. The review underscores that phase-change materials enhanced with graphene, boron nitride, and carbon nanofibers offer superior thermal conductivity, phase stability, and flexibility, making them ideal for wearable applications. Shape-stabilized phase-change materials and aerogel-infused fibers have shown promising results in outdoor, industrial, and emergency settings due to their durability and high insulation efficiency. Radiative cooling textiles, engineered with hierarchical nanostructures and Janus wettability, demonstrate passive temperature regulation through selective solar reflection and infrared emission, achieving substantial cooling effects without external energy input. Thermo-responsive, shape-memory materials, and moisture-sensitive polymers enable dynamic insulation and actuation. Liquid-cooling garments and thermoelectric hybrids deliver precise temperature control but face challenges in portability and power consumption. While thermoregulating textiles show promise, the main challenges include achieving scalable manufacturing, ensuring material flexibility, and integrating multiple functions without sacrificing comfort. Future research should focus on hybrid systems combining passive and active mechanisms, user-centric wearability studies, and cost-effective fabrication methods. These innovations hold significant potential for applications in extreme environments, athletic wear, military uniforms, and smart clothing, contributing to energy efficiency, health, and comfort in a warming climate. Full article

The extensive use of lithium-ion batteries and other energy storage systems (ESS) in recent years has resulted in a critical need for effective thermal management solutions that ensure safe and reliable operations. Carbon-based materials (C-bMs) are a promising candidate for addressing the thermal challenges in ESS due to their unique thermal, electrical, and structural properties. This article provides a concise overview of C-bM thermal management solutions for improved battery safety. The key thermal management requirements and failure modes associated with battery systems are highlighted, underscoring the importance of effective battery thermal management (BTM). Various forms of C-bMs, including graphite, graphene, carbon nanotubes, carbon foams, nanodiamonds, and graphdiyne, are examined for their potential applications in battery thermal management systems. The recent innovations and advancements in C-bM thermal management solutions, such as phase change composites, heat pipes, and thermal interface materials, are highlighted. Furthermore, the latest research trends focus mainly on the development of hybrid battery thermal management solutions, carbon-based aerogels, and complex C-bM structures with tailored thermal pathways for optimized thermal management. Most of the current innovations are still at the laboratory scale; hence, future research efforts will be focused on developing integrated multi-functional C-bMs, sustainable and scalable manufacturing techniques, self-healing C-bMs composites, intelligent C-bMs, and further explorations of uncommon C-bMs. These advancements are bound to enhance performance, sustainability, and application-specific adaptations for BTM. This article provides valuable insights for researchers, and stakeholders interested in leveraging C-bMs for BTM. Full article

This review summarizes the current knowledge in the field of preparing new and/or innovative materials that can be advantageously used for the sorption of emerging pollutants from water. This paper highlights new innovative materials such as transition metal-modified biochar, zeolites, clays, carbon fibers, graphene, metal organic frameworks, and aerogels. These materials have great potential for the removal of heavy metals from water, particularly due to their large surface area, nanoscale size, and availability of various functionalities; moreover, they can easily be chemically modified and recycled. This paper not only highlights the advantages and ever-improving physicochemical properties of these new types of materials but also critically points out their shortcomings and suggests possible future directions. Full article

A supercapacitor’s energy storage capability is greatly dependent on electrode materials. Layered double hydroxides (LDHs) were extensively studied as battery-type electrodes because of their 2D structure and quick intercalation/deintercalation of electrolyte ions. However, the energy storage capability for pristine LDHs is limited by their large aggregation tendency and poor electrical conductivity. Herein, a novel NiCoMn-LDH/SWCNTs (single-walled carbon nanotubes) composite electrode material, with ultrathin NiCoMn-LDH nanosheets dispersedly grown among the highly conductive networks of SWCNTs, was prepared via a facile zeolitic imidazolate framework-67 (ZIF-67)-derived in situ etching and deposition procedure. The NiCoMn-LDH/SWCNTs electrode demonstrates a specific capacitance as large as 1704.3 F g⁻¹ at 1 A g⁻¹, which is ascribed to its exposure of more active sites than NiCoMn-LDH. Moreover, the assembled NiCoMn-LDH/SWCNTs//BGA (boron-doped graphene aerogel) hybrid supercapacitor exhibits a superior capacitance of 167.9 F g⁻¹ at 1.0 A g⁻¹, an excellent energy density of 45.7 Wh kg⁻¹ with a power density of 700 W kg⁻¹, and an outstanding cyclic stability with 82.3% incipient capacitance maintained when subjected to 5000 charge and discharge cycles at the current density of 10 A g⁻¹, suggesting the significant potential of NiCoMn-LDH/SWCNTs as the electrode material applicable in supercapacitors. Full article

The mechanical stability of carbon aerogels, particularly their thermal insulation performance, is closely linked to their elastic modulus. This property plays a crucial role in determining the material’s overall mechanical stability. The objective of this study is to enhance the accuracy of elastic modulus predictions for carbon aerogels using a power-scaling model. By setting the prefactor of the Gibson and Ashby equation to 1.0, accurate predictions of the elastic modulus can be achieved if the correct scaling exponent is determined. Twelve sets of experimental data were used to fit the power-scaling model, revealing that the scaling exponent for the elastic modulus of carbon aerogels typically falls between 2.2 and 3.0. This range is narrower than the 2.0 to 4.0 range reported in the literature, with a median value of 2.6 providing reliable predictions. Additionally, a relationship between the solid thermal conductivity and the elastic modulus of carbon aerogels was established using a thermal conduction model. The study also examined the elastic modulus of carbon nanotube and graphene aerogels—both allotropes of carbon aerogel. By fitting experimental data into the power-scaling model, the scaling exponents for carbon nanotube aerogels and graphene aerogels were found to range from 2.7 to 3.5 and 2.7 to 3.7, respectively. Median exponent values of 3.1 and 3.2 were identified as optimal for predicting the elastic moduli of carbon nanotube and graphene aerogels. Full article

In this study, we report the findings of a morphological analysis of a resorcinol–formaldehyde (RF)-based carbon aerogel (CA) and its graphene oxide (GO)-doped version (CA-GO), prepared for possible applications as an electrode material. Beyond some electron microscopic and N₂ sorption investigations, we mostly used NMR cryoporometry and relaxometry to characterize the gels in a wet state, as they are usually applied. The precursor RF polymer aerogel was prepared both with and without GO and was subsequently carbonized into carbon aerogel. Modifying the polymer aerogel using GO resulted in a larger variety of C-O bonds in both polymer aerogels. However, the most important changes occurred in the morphology of the carbon aerogels. NMR relaxometry revealed the highly hydrophilic nature of the pore wall of the RF polymer aerogels, as demonstrated by their uniform wetting behavior. The carbonization resulted in a mostly hydrophobic pore wall decorated by some oxygen-containing spots and a macroporous system. Doping with GO after pyrolysis resulted in spherical pores in the CA and cylindrical pores in the CA-GO, which is potentially a more promising material for electrochemical use than CA. Full article

Textile industry waste contains high concentrations of heavy metals such as Pb(II) and Cr(VI) that must be reduced before they are released to the environment. The adsorption method is one way to reduce the heavy metal content. In this work, we develop a porous cellulose nanofiber (CNF) aerogel modified with graphene oxide (GO) as an alternative aerogel adsorbent for Pb(II) and Cr(VI). Cellulose was extracted from banana peduncle, a biomass waste that remains largely underutilized. The addition of GO aims to increase the adsorption properties. The aerogel adsorbents were synthesized by varying the ultrasonication time to 45 min for CNF 45 and 60 min for CNF 60, and the amount of GO added to 1 mL and 2 mL. The aerogel adsorbents were successfully prepared using the freeze-drying method with CNF45, CNF60, CNF45/GO1, CNF45/GO2, CNF60/GO1, and CNF60/GO2 variations. CNF was successfully isolated from a banana peduncle with an average diameter of 44.16 nm for 45 min (CNF 45) and an average diameter of 14.6 nm for 60 min (CNF 60) of ultrasonication. Chemical treatment and ultrasonication reduced the crystallinity index value of cellulose by 73% and 61% for CNF 45 and CNF 60, respectively. CNF aerogel has a very low shrinkage rate (<7%), resulting in a larger surface area. CNF60/GO2 obtained the optimum adsorption ability for Pb(II) metal at a concentration of 100 ppm and 27.27 mg/g at 30 min. On the other hand, the adsorption ability of Cr(VI) metal was obtained by CNF60/GO2 at a concentration of 100 ppm and 13.48 mg/g at 30 min. SEM images show that all aerogel adsorbents are porous, with a porosity value range of 96–98%. In conclusion, CNF60/GO2 proved to be the most effective aerogel adsorbent, offering the potential for heavy metal removal from industrial wastewater. Full article

In the present work, the influence of the addition of graphene nanoplatelets presenting different dimensions on polyurethane–polyisocyanurate aerogel structure and properties has been studied. The obtained aerogels synthesized through a sol–gel method have been fully characterized in terms of density, porosity, specific surface area, mechanical stiffness, thermal conductivity, and speed of sound. Opacified aerogels showing high porosity (>92%) and low densities (78–98 kg/m³) have been produced, and the effect of the size and content of graphene nanoplatelets has been studied. It has been observed that formulations with less than 5 wt.% of graphene nanoplatelets larger than 2 microns can effectively reduce the total thermal conductivity by absorption and scattering of the infrared radiation, reducing the heat transfer by this mechanism. The resulting opacified samples are highly insulating materials, with thermal conductivities less than 18 mW/m·K. Moreover, it has been observed that smaller particles with ca. 200 nm of average length can promote an increase in the elastic modulus, therefore obtaining stiffer aerogels, combined with thermal conductivities lower than 20 mW/m·K. Results have been studied in detail, providing a further understanding of the mechanisms for improving the final properties of these materials, making them more suitable for industrial applications. Full article

Dyes abundance in industrial wastewater exerts adverse effects on the environment and human health; adsorption represents a promising remediation strategy. Chitosan-based composites are interesting materials for dye adsorption. In this work, methyl orange (MO) adsorption using chitosan (CH) and chitosan–graphene oxide (CH-GO) aerogels produced by supercritical gel drying, performed at 200 bar/35 °C, was assessed by studying the effect of driving force (25–100 ppm) and adsorbent dosage (1–8 g/L). It was highlighted that the difference in the performance between the two adsorbents was non-negligible only at high concentrations: processing a 100 ppm MO solution, q_eq is 59 mg/g and 28 mg/g for CH-GO and CH, respectively. Starting from a 10 ppm MO solution, using a dosage of 8 g/L, it was possible to achieve adsorption efficiency of about 85%, meaning that small amounts of nanostructured devices can result in good process outcomes. Freundlich isotherm reliably describes the system behavior (R² = 0.99). The multi-linear IPD kinetic model confirms that in the case of nanostructured porous devices, there are different mass transfer phenomena that control molecule diffusion through the system. The research proposed in this work aims to explore, as a first assessment, the potential of nanostructured devices for adsorption purposes. Full article

Graphene aerogels with high surface areas, ultra-low densities, and thermal conductivities have been attracted a lot of attention in recent years. However, considerable difference in their deformation behavior and mechanical properties lead to their poor performance. The problem can be solved by preparing graphene aerogel of given morphology and by control the properties through the special structure of graphene cells. In the present work, molecular dynamics simulation is used to overview the mechanical properties of four different morphologies of graphene aerogel: honeycomb, cellular, lamellar and randomly distributed graphene flakes. All the structures are considered under uniaxial compression and tension with the detailed analysis of the deformation behavior. It is found that cellular structures have much better compressibility and elasticity. During both compression and tension, cellular structures can be transformed from one to another by controlling the compression/tensile direction. The highest strength and fracture strain are found for the lamellar GA under tension along the direction perpendicular to the alignment of the graphene walls. This reveals that the mechanical properties of graphene aerogels can be controlled by enhancing the structural morphology. The obtained results is the contribution which provide the insights into recent developments concerning the design of carbon-based structures and their application. Full article

Carbon nanostructures are highly promising materials for applications in a variety of different fields. Besides their interesting performances, the possibility to synthesize them from biowaste makes them an eco-friendly resource widely exploitable within a circular economy context. The present work deals with the green, one-pot synthesis of graphene quantum dots (GQDs) from carbon aerogels (CAs) derived from rice husk (RH). After having obtained CAs upon purification of RH, followed by gelification and carbonization of the resulting cellulose, the one-pot solventless production of GQDs was obtained by ball milling. This method determined the formation of crystalline nanostructures with a diameter of around 20 nm, which were analyzed via scanning electron microscopy, transmission electron microscopy, atomic force microscopy, X-ray diffraction, and Raman spectroscopy to obtain a full morphological and structural characterization. GQDs were used as electrode materials for supercapacitors and Li-ion batteries, showing the ability to both accumulate charges over the surface and intercalate lithium-ions. The reported results are a proof of principle of the possibility of exploiting GQDs as support material for the development of advanced systems for energy storage. Full article