Graphene-based Composites Research Articles

Investigating the environmental impacts of lithium-oxygen battery cathode production: A comprehensive assessment of the effects associated with oxygen cathode manufacturing

Lithium-oxygen batteries offer remarkably high energy density compared to current lithium-ion batteries. The key to their electrochemical performance lies in the processes occurring at the air cathode. However, the complexity of these reactions, coupled with the by-products generated during discharge, can make the reaction process slow or impede their efficiency. This study evaluates the environmental impact of high-efficiency lithium-oxygen batteries cathodes, including titanium oxide composites, graphene-based composites and activated carbon-based composites, through a life cycle assessment across 18 impact categories using a cradle-to-gate approach with a functional unit of 25 kWh. Results show that active material production was the largest contributor to environmental impact, particularly Global Warming Potential. Among the evaluated cathodes, reduced graphene oxide/α-mnaganese oxide/palladium (rGO/α-MnO2/Pd) demonstrated the highest environmental impact, with a global warming potential of 1130.71 kg carbon dioxide from active material production, due to its energy-intensive synthesis and the use of chemicals like sulfuric acid, sodium borohydride, hydrochloric acid, and hydrogen peroxide. Additionally, the rGO/α-MnO2/Pd cathode had the highest Human Toxicity Potential and Ozone Depletion Potential. Batteries with graphene-based cathodes achieved a specific capacity of 7500 mAh.g-1, underscoring their performance potential while highlighting the need for more sustainable cathode manufacturing methods. These findings emphasize the environmental considerations necessary for large-scale lithium-oxygen batteries implementation.

CVD graphene with high electrical conductivity: empowering applications

Abstract Graphene is an extraordinary material boasting a unique structure, enthralling properties, and promising application vistas. Particularly, the remarkable electrical conductivity of graphene confers it with an inimitable superiority in multiple fields. Endeavors have been continuously made to progressively elevate the conductivity of graphene materials that are synthesized using chemical vapor deposition (CVD), the primary means to prepare high-quality graphene in batches. From this perspective, we offer a comprehensive analysis and discussions on the growth, transfer, and post-treatment strategies evolved towards highly conductive graphene over the past five years. Large-area graphene films, ranging from monolayer to multilayer ones, are initially addressed, succeeded by graphene-based composites which enable traditional metals and non-metal materials to showcase novel or enhanced electrical performances. Eventually, an outlook for future directions to achieve higher electrical conductivity and to develop novel applications for CVD graphene materials is provided.

Advances in photocatalytic degradation of tetracycline using graphene-based composites in water: a systematic review and future directions.

In this study, a comprehensive systematic review was conducted to better recognize the applicability of graphene-based photocatalytic processes for the degradation of tetracycline (TC) from water. A broad search strategy was developed for English language articles available in PubMed, Scopus, and Web of Science. The effect of parameters such as pH, TC concentration, photocatalyst dose, radiation source intensity, and the effect of graphene on the process, kinetics, and reuse of the photocatalyst were investigated. A total of 63 out of a possible 3498 retrieved records met inclusion criteria. The results showed that most related studies have increased since 2019. About 46.7% of the articles showed 90-100% TC removal efficiency and 59.52% of the studies had optimal pH equal to 5 and 6. Also, the widespread use of visible light had a significant trend. The effect of the dose of graphene in the catalyst was one of the most important and effective factors on the process; hence, the difference in efficiency with and without graphene was completely evident. This review indicated that the presence of graphene has been able to have a positive effect on increasing the efficiency of oxidation processes, and it can be used for environmental pollutants remediation.

Mechanobiological mechanisms in the remediation of soil lead pollution using two-dimensional carbon materials and Morchella: A molecular-level study

Graphene-based 2D carbon composites and Morchella mushrooms are used in the paper to study the mechanobiological mechanisms of soil lead remediation. Soil is contaminated with lead, which threatens ecosystems and human health, making it even more important to find remedies. To fully comprehend these processes, present-day materials, and organic compounds are needed to improve soil nutrition and eradicate lead. To deal with the challenge of finding effective means of lead removal; limitations associated with traditional soil pollution remediation methods; and merging biology and material sciences. Multifunctional graphene wettability-patterned nanocoated membranes (MGW-PNM) is a novel technique developed to overcome these challenges. Such processes result in membranes with different wettability patterns that take advantage of the properties of graphene. This facilitates better interaction between the membrane itself and the surrounding soil as well as lead contaminants by modifying its hydrophobicity or hydrophilicity characteristics. For effective removal of lead, extensive simulation studies were done using MGW-PNM. In line with this, it can be inferred that MGW-PNM also remediates highly capable soils at high-efficiency levels. This was established when comparing modern techniques to past ones where considerable improvements were made on how much lead is extracted from them. The study suggests new ways of addressing environmental contamination resulting from microbial activities in soils by combining advanced materials with biological substances such as Morchella spp. For this purpose, it investigates various molecular interactions occurring among carbonaceous species called Morchella microbes and environmental pollutants like those including Pb.

Recent Progress of Three-Dimensional Graphene-Based Composites for Photocatalysis.

Converting solar energy into fuels/chemicals through photochemical approaches holds significant promise for addressing global energy demands. Currently, semiconductor photocatalysis combined with redox techniques has been intensively researched in pollutant degradation and secondary energy generation owing to its dual advantages of oxidizability and reducibility; however, challenges remain, particularly with improving conversion efficiency. Since graphene's initial introduction in 2004, three-dimensional (3D) graphene-based photocatalysts have garnered considerable attention due to their exceptional properties, such as their large specific surface area, abundant pore structure, diverse surface chemistry, adjustable band gap, and high electrical conductivity. Herein, this review provides an in-depth analysis of the commonly used photocatalysts based on 3D graphene, outlining their construction strategies and recent applications in photocatalytic degradation of organic pollutants, H2 evolution, and CO2 reduction. Additionally, the paper explores the multifaceted roles that 3D graphene plays in enhancing photocatalytic performance. By offering a comprehensive overview, we hope to highlight the potential of 3D graphene as an environmentally beneficial material and to inspire the development of more efficient, versatile graphene-based aerogel photocatalysts for future applications.

Innovative Adsorbents for Pollutant Removal: Exploring the Latest Research and Applications.

The growing presence of diverse pollutants, including heavy metals, organic compounds, pharmaceuticals, and emerging contaminants, poses significant environmental and health risks. Traditional methods for pollutant removal often face limitations in efficiency, selectivity, and sustainability. This review provides a comprehensive analysis of recent advancements in innovative adsorbents designed to address these challenges. It explores a wide array of non-conventional adsorbent materials, such as nanocellulose, metal-organic frameworks (MOFs), graphene-based composites, and biochar, emphasizing their sources, structural characteristics, and unique adsorption mechanisms. The review discusses adsorption processes, including the basic principles, kinetics, isotherms, and the factors influencing adsorption efficiency. It highlights the superior performance of these materials in removing specific pollutants across various environmental settings. The practical applications of these adsorbents are further explored through case studies in industrial settings, pilot studies, and field trials, showcasing their real-world effectiveness. Additionally, the review critically examines the economic considerations, technical challenges, and environmental impacts associated with these adsorbents, offering a balanced perspective on their viability and sustainability. The conclusion emphasizes future research directions, focusing on the development of scalable production methods, enhanced material stability, and sustainable regeneration techniques. This comprehensive assessment underscores the transformative potential of innovative adsorbents in pollutant remediation and their critical role in advancing environmental protection.

Drop-weight impact and compressive behavior of graphene-based carbon fiber-reinforced polymer composites

Drop-weight impact and compressive behavior of graphene-based carbon fiber-reinforced polymer composites

Synergistic effect of Prussian Blue, Ceria, and reduced graphene oxide in ternary nanocomposite PBNCs-CeO2-rGO for electrochemical detection of hydrogen peroxide

Graphene-based ternary composites incorporating rare earth metals have garnered significant attention for their potential in low-detection applications of hydrogen peroxide (H2O2), owing to their cost-effectiveness and facile synthesis methods. In this study, we have reported the synergistic effect of Prussian blue nanocubes (PBNCs), reduced graphene oxide (rGO), and ceria nanoparticles (CeO2) in the ternary nanocomposite, i.e., PBNCs-CeO2-rGO for a low detection of H2O2. The enhanced electrocatalytic activity of ternary composite as compared to bare PBNCs and CeO2 nanoparticles was evidenced in different electrochemical methods such as Electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and Amperometry. The synthesized material was comprehensively characterized using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), Fourier-transform infrared spectroscopy (FTIR), and Raman spectroscopy. Remarkably, the synthesized material exhibited a low detection limit of up to 2.08 nM and a high sensitivity of 8671.6 μA mM−1 cm−2. Furthermore, the synthesized material demonstrated excellent selectivity, good reproducibility, and high stability, highlighting its potential for various sensing applications.

Flexible composite films with ultrahigh through-plane thermal conductivity yet low graphene content

Graphene-based polymeric composites have become one of the promising thermal interface materials (TIMs) for the high integration electronic devices due to the excellent intrinsic thermal conductivity of graphene. However, the challenges still remain, such as ordered alignment of graphene in elastic polymer and regulation of phonon scattering at graphene/graphene interface. In this study, a vertically oriented graphene framework within a flexible silicone rubber matrix was fabricated by non-solvent induced phase separation (NIPs) coupled with an in in-situ welding technique. The as-prepared film exhibits an outstanding through-plane thermal conductivity of 29.5W/mK at low graphene loading of 7.5 wt%, which indicates an exceptionally high thermal conductivity enhancement per 1 wt% graphene content (specific TCE) over 1950 %/wt%. Furthermore, the composite films demonstrate excellent conformability inherited from the silicone rubber matrix and achieves low contact resistance of 40–70 Kmm2W−1 under various pressure and interfacial conditions. This study contributes to a deeper insight into the development of the high-performance graphene-based polymeric TIMs.

Graphene Oxide Covalently Functionalized with 5-Methyl-1,3,4-thiadiazol-2-amine for pH-Sensitive Ga3+ Recovery in Aqueous Solutions.

A novel graphene-based composite, 5-methyl-1,3,4-thiadiazol-2-amine (MTA) covalently functionalized graphene oxide (GO-MTA), was rationally developed and used for the selective sorption of Ga3+ from aqueous solutions, showing a higher adsorption capacity (48.20 mg g-1) toward Ga3+ than In3+ (15.41 mg g-1) and Sc3+ (~0 mg g-1). The adsorption experiment's parameters, such as the contact time, temperature, initial Ga3+ concentration, solution pH, and desorption solvent, were investigated. Under optimized conditions, the GO-MTA composite displayed the highest adsorption capacity of 55.6 mg g-1 toward Ga3+. Moreover, a possible adsorption mechanism was proposed using various characterization methods, including scanning electron microscopy (SEM) equipped with X-ray energy-dispersive spectroscopy (EDS), elemental mapping analysis, Fourier transform infrared (FT-IR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). Ga3+ adsorption with the GO-MTA composite could be better described by the linear pseudo-second-order kinetic model (R2 = 0.962), suggesting that the rate-limiting step may be chemical sorption or chemisorption through the sharing or exchange of electrons between the adsorbent and the adsorbate. Importantly, the calculated qe value (55.066 mg g-1) is closer to the experimental result (55.60 mg g-1). The well-fitted linear Langmuir isothermal model (R2 = 0.972~0.997) confirmed that an interfacial monolayer and cooperative adsorption occur on a heterogeneous surface. The results showed that the GO-MTA composite might be a potential adsorbent for the enrichment and/or separation of Ga3+ at low or ultra-low concentrations in aqueous solutions.

Conductive graphene-based coagulated composites for electronic printing applications

Graphene is gaining significance in applications such as sensors, antennas, photonics and spintronics. In particular, it is suitable for printing components and circuits affording the properties of high conductivity alongside flexibility, elasticity and wearability. For this application, graphene is typically customised into a fluidic form—ink or paint. This paper reports a novel, economical, scalable methodology for synthesising electrically conductive graphene-based coagulated composite that could be utilised in the above-mentioned applications. Composites are prepared from graphene powder/ink and screen-printing ink (GP–SPI and GI–SPI, respectively) at different mass ratios, and the optimal composition is identified by brush coating on paper in the form of rectangular strips. As a proof of concept, at optimum mass ratios, the GP–SPI and GI–SPI composites exhibit electrical conductivities ranging 0.068–0.702 mS m−1 and 0.0303–0.1746 μS m−1, in order. The as-prepared conductive composites are then screen-printed onto a square with an area of 1 cm2 on ceramic, FR4, glass, paper, polyester and wood substrates. The coagulated GP–SPI and GI–SPI composites are compatible with all these substrates and yield a conductive coating, demonstrating their suitability in multifaceted applications. Furthermore, the method proposed herein eliminates the need for rare/precious expensive materials, state-of-the art equipment, highly skilled personnel and costs associated with the same, thereby broadening the avenues for low-cost, fluidic graphene-based functional composites.

Bulk graphene-based composites with artificial nacre-like laminated structure: Microstructure and mechanical properties

In this study, the bulk Cu/reduced graphene oxide (Cu/rGO) composites featuring an artificial nacre-like laminated structure were successfully fabricated using spark plasma sintering (SPS), and the microstructure and mechanical properties of the resulting composites were investigated. The Cu/rGO composites demonstrated a distinct laminated structure, and their relative densities increase with Cu addition. Moreover, the presence of trace amounts of in-situ interfacial reaction products (CuO and CuO2,) were observed to enhance the adhesive strength at the Cu-rGO interface. Mechanical testing of the composites showed notable improvements in both compressive strength and ductility compared to a bulk monolithic rGO sample. Specifically, the bulk rGO composites with a 35.05 wt% addition of Cu displayed an enhancement of ∼67 % in compressive strength and ∼19 % in ductility relative to the pure rGO sample. These improvements are attributed to synergetic strengthening and toughening mechanisms within the rGO composites. The enhanced strength and ductility of the Cu/rGO composites significantly boost their wear resistance. This research not only demonstrates the effectiveness of incorporating Cu into rGO matrices but also suggests a promising avenue for the development of novel bulk rGO composites with engineered laminated structures.

Retraction Note: Investigation on the role of graphene-based composites for in photocatalytic degradation of phenol-based compounds in wastewater: a review.

Retraction Note: Investigation on the role of graphene-based composites for in photocatalytic degradation of phenol-based compounds in wastewater: a review.

Dual role of two-dimensional graphene in silica aerogel composite: Thermal resistance and heat node

Incorporating two-dimensional graphene sheets, known for their high in-plane thermal conductivity, into silica aerogel enhances both the thermal insulation and mechanical properties of the composite. This work delves into the impact of graphene doping on the solid thermal conductivity of silica composites and their mechanical characteristics, employing molecular dynamics simulations that encompass both amorphous silica bulk and porous silica aerogel structures. Our findings reveal that graphene–silica interface thermal resistance notably restricts heat conduction in graphene doped silica aerogel, with the most pronounced effect occurring when graphene aligns vertically with the heat flux. Within porous silica aerogel, graphene serves as a “heat node”, bridging and connecting adjacent pores. A notable “trade-off” emerges: high weight percentages of graphene sheets augment heat transfer through the “heat node effect”, whereas the interfacial thermal resistance between graphene and aerogel reduces solid heat transfer, leading to decreased thermal conductivity. Additionally, while the inclusion of graphene sheets offers limited mechanical property enhancements, their two-dimensional structure can cause detachment and slipping from the silica matrix, leading to localized improvements in mechanical strength. This work sets the stage for advancing graphene-based aerogel composites characterized by low thermal conductivity and enhanced mechanical properties.

Molecular modeling analysis for functionalized graphene/sodium alginate composite

This study examined the functionalization of graphene with easily ionizable elements, such as lithium, and subsequently its interaction with the biopolymer sodium alginate (SA), to highlight its potential for biomedical applications. Utilizing Density Functional Theory (DFT), the research comprehensively investigated the structural, electronic, and spectroscopic properties of these graphene-based composites. The electronic properties of functionalized graphene were investigated using DFT at the B3LYP/6-31G(d,p) level. Among the various configurations studied, graphene exhibited weak interaction with two lithium atoms, displaying the highest reactivity in terms of total dipole moment (TDM) at 5.967 Debye and a HOMO/LUMO energy gap (ΔE) of 0.748 eV. Electrostatic potential mapping revealed that graphene when enhanced with lithium and three units of SA, exhibited an augmented potential density on its surface, a finding corroborated by other investigated physical properties. Notably, the configuration of graphene/3SA/Li, with weak interaction occurring at two side carbons, demonstrated the highest reactivity with a TDM of 15.509 Debye and ΔE of 0.280 eV. Additionally, a shift in the spectral characteristics of graphene towards lower wavenumbers was observed as lithium and SA interacted with the graphene substrate. The PDOS plot for Graphene/3SA/Li, showed the highest contribution in the HOMO orbitals was equally from lithium, sodium, hydrogen, and oxygen, while the lowest contribution was from carbon. This computational analysis provides comprehensive insights into the functionalized graphene systems, aiding in their further development and optimization for practical biomedical use.

Aluminum/Graphene Thermal Interface Materials with Positive Temperature Dependence.

Graphene is widely used in excellent thermal interface materials (TIMs), thanks to its remarkably high in-plane thermal conductivity (k∥). However, the poor through-plane thermal conductivity (k⊥) limits its further application. Here, we developed a simple in situ growth method to prepare graphene-based thermal interface composites with positively temperature-dependent thermal conductivity, which loaded aluminum (Al) nanoparticles onto graphene nanoplatelets (GNPs). To evaluate the variations in thermal performance, we determined the thermal diffusivity and specific heat capacity of the composites using a laser-flash analyzer and a differential scanning calorimeter, respectively. The Al nanoparticles act as bridges between the nanoplatelets, enhancing the k⊥ of the 1.3-Al/GNPs composite to 11.70 W·m-1·K-1 at 25 °C. Even more remarkably, those nanoparticles led to a unique increase in k⊥ with temperature, reaching 20.93 W·m-1·K-1 at 100 °C. Additionally, we conducted an in-depth investigation of the thermal conductivity mechanism of the Al/GNPs composites. The exceptional heat transport property enabled the composites to exhibit a superior heat dissipation performance in simulated practical applications. This work provides valuable insights into utilizing graphene in composites with Al nanoparticles, which have special thermal conductivity properties, and offers a promising pathway to enhance the k⊥ of graphene-based TIMs.

3D hierarchical graphene-based composite for ultra-high heat-conducting film

In order to pursue lightness and portability, modern electronic devices usually use a compact layout to place various components, but this highly integrated design increases the heat density of the device and causes heat accumulation. Excessive heat accumulation will reduce the reliability of the device and even cause thermal failure. The advantages of light weight, easy processing and low cost of polymer-based thermally conductive composites have become main concerns of modern thermal management materials, but the low thermal conductivity (TC) has seriously limited their application. Here, 3D hierarchical anisotropic oriented graphene-based composites with high TC are fabricated by layer-by-layer self-assembling of one-dimensional carboxylated cellulose nanofibers (CNF–C) and poly dopamine modified nickel particle-coated two-dimensional graphene nanosheets (PDA-Ni@GNS). Owing to the well-defined flaky packing layers and the hydrogen bonding, the composite exhibits not only sufficiently high in-plane TC of 28.8 W m−1 K−1 and tensile strength of 124 MPa, but also exhibits hydrophobic property. A generalized four-parameter model (FPM) is found to reasonably predict the entire CPU temperature evolution versus time. This work presents a facile strategy for constructing 3D hierarchical interfacial structure to obtain excellent versatility of anisotropic thermal management composites.

Enhanced microwave absorption in graphene-based composites: A study on the synergistic effect of ferrite integration and electromagnetic coupling

Graphene integration with magnetic particles demonstrates a synergistic enhancement in dielectric and magnetic loss properties, facilitating the realization of absorbing materials that are strong, broadband, lightweight, and thin. This study achieved uniform dispersion of ferrite on the surface of in-situ synthesized high-conductivity graphene, utilizing an economical liquid glucose precursor and cobalt ferrite sintering process. An interface consisting of iron carbide and cobalt-iron alloy forms between the graphene and cobalt ferrite, significantly enhancing the samples’ microwave absorption performance. Furthermore, the magnetic loss is notably enhanced through the coupling of soft and hard magnetic materials. Consequently, a composite material consisting of Graphene/Fe3C/CoFe2/CoFe2O4, with a minimal thickness of 1.85 mm, demonstrated an impressive minimum reflection loss of −48.8 dB and a notable absorption bandwidth extending over 4.04 GHz. This research will offer an effective approach for developing high-performance microwave absorption materials using graphene-based composite magnetic materials.

Boron-graphene composite for efficient electromagnetic interference shielding with strong strength and near-zero thermal expansion

The quest for the materials that boast efficient electromagnetic interference (EMI) shielding, strong strength and superb thermal dimensional stability is a burgeoning research area, particularly due to their critical applications in safeguarding sensitive circuits against microwave radiation, especially in the space environments. Graphene-based composites, leveraging the remarkable attributes of individual graphene nanosheets, emerge as prime contenders for fulfilling these sophisticated application requirements. In this study, we prepared boron-graphene composites via spark sintering, combining graphene sheets and boron nanoparticles. This method not only ensures high-performance outcomes but also remains cost-effective and suitable for large-scale production. Boron serves as a binder, facilitating the connection between adjacent graphene sheets and enhancing the graphitization process. The resulting composites demonstrated exceptional electrical conductivity (4.53 × 105 S m−1) and superior EMI shielding effectiveness (average SET 83 dB, with the thickness of 0.25 mm), markedly surpassing previous graphene-based materials in terms of compressive strength (171.3 MPa), and exhibiting low thermal expansion and an ultra-low friction coefficient (0.04). Additionally, to unravel the evolution of boron in the graphene composite and the impact of boron on electrical conductivity, first principles calculations and density functional theory (DFT) were utilized. This investigation underscores the significant promise of boron-graphene composites as high-performance, multifunctional materials across various domains.

Unveiling transformative potential: recent advances in graphene-based polymer composites

Unveiling transformative potential: recent advances in graphene-based polymer composites