Graphene-based Carbon Research Articles

Low-cost flash graphene from carbon black to reinforce cementitious composites for carbon footprint reduction

With the merits of high quality, cost-effectiveness, and high yield efficiency, flash Joule heating (FJH) emerges as an efficient means for mass production of flash graphene (FG). It creates prerequisites for the large-scale application of graphene in reinforcing cementitious composites, thus opening innovative possibilities for curbing carbon emissions and fostering the sustainable evolution of cementitious composites. In this study, two types of FGs, including high-purity FG (FG-G) and conductive FG (FG-D), are successfully synthesized via FJH process using carbon black as the carbon source. FG-G features a low ID/IG of 0.52, and exhibits higher graphitization and structural orderliness with fewer defects compared to the FG-D. The addition of 0.25 wt% FG-D increases the compressive strength, flexural strength, and flexural ultimate strain of cementitious composites by 16.48 MPa/16.8%, 1.43 MPa/37.2%, and nearly 2600 με/550%, respectively. The microstructure characterization results reveal that FG reduces the matrix defects, enhances both the matrix microstructure and calcium silicate hydrate gel nanostructure, which is advantageous for matrix refinement, inhibition of microcrack aggregation and propagation, and load transfer efficiency. Its disorderly stacked turbine structure also contributes to robust interface bonding and friction with cement matrix, thus facilitating the strengthening and toughening of cementitious composites. This study introduces a potential avenue to develop widely applicable and versatile silicon-based cementitious composites with high performance and low CO2 emission by using small carbon-based graphene as reinforcement.

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.

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

Highly porous biomass-derived graphene-based carbons for removal of phenol from wastewater

This study explores the effectiveness of highly porous graphene-based carbons derived from biomass as an adsorbent for removing phenol from aqueous solutions. The graphene-based carbons were extensively characterized using electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and BET analysis. They predominantly consisted of sp2-bonded carbons and demonstrated an exceptionally high specific surface area with an interconnected pore structure. This unique structure enables effective phenol adsorption primarily through favorable π-π interactions, resulting in outstanding adsorption capacity. Both Langmuir and Freundlich isotherm models provided excellent fits to the adsorption data, confirming the favorable phenol adsorption characteristics of the carbons. Furthermore, the adsorption kinetics were well-described by non-linear pseudo-first-order (PFO), pseudo-second-order (PSO), and linear intraparticle diffusion (IPD) models, indicating that phenol adsorption occurs through a physisorption mechanism involving the phenolic ring and the basal plane of the carbon. This study underscores the potential of biomass-derived graphene-based carbon as a cost-effective and efficient adsorbent for phenol removal, offering promising implications for sustainable water treatment solutions.

Retraction Note: Graphene-Based Important Carbon Structures and Nanomaterials for Energy Storage Applications as Chemical Capacitors and Supercapacitor Electrodes: a Review

Retraction Note: Graphene-Based Important Carbon Structures and Nanomaterials for Energy Storage Applications as Chemical Capacitors and Supercapacitor Electrodes: a Review

Unraveling Water-Based Lubrication with Carbon Dots of Asphaltene Origin.

Despite the lower toxicity of water-based lubricants over nonrenewable petroleum-based analogues, they face challenges in achieving widespread adoption due to low stability and inadequate friction-reduction performance. To address this, a cost-effective nanoadditive is synthesized by expansive oxidation of asphaltenes to create biocompatible asphaltene-derived carbon dots [(ACDs); 5 nm]. These ACDs exhibit excellent water redispersibility, promoting long-term friction reduction and marking the first use of an asphaltene-based system for friction reduction in water or oil. Even at low loadings (0.2-4.0 wt %), ACDs significantly reduce friction on steel surfaces (>54%) with tribofilm stability surpassing pristine carbon dots, typical carbon-based graphene quantum dots, and inorganic nanomaterials (commercial 5 and 20 nm silica). The ACDs' attributes include high negative zeta potential, considerable water uptake, varied functional groups, biocompatibility, and a nanodisc shape conducive to stable tribofilm formation through effective particle stacking. The scalable synthesis, high yield, and impressive water redispersibility of ACDs position them favorably for commercial water-based lubrication.

Designed MoSe2 modified multi-layer hollow carbon fiber composite material achieves tunable electromagnetic wave absorption in the X and Ku bands

As a substitute for graphene-based carbon materials, carbon fiber (CF) based absorbing materials have enormous application prospects. Effective improvements have been made in solving the problems of heavy quality and complex preparation processes of ordinary absorbing materials. In order to obtain a flexible thin fiber membrane absorbing material with good stability and excellent performance, we prepared a multi-layer hollow carbon sphere/CF@MoSe2 with carbon fiber as the matrix, and controlled the microstructure through hollow carbon shell and MoSe2, and introduced transition metal chalcogenides to coordinate electromagnetic parameters. As a result, the hollow carbon sphere/CF@MoSe2 flexible composite film achieved a minimum reflection loss (RLmin) of −47.98 dB at a thickness of 2.5 mm, and an effective bandwidth (EAB) of 8.1 GHz at a thickness of 2.7 mm. The RLmin of the hollow carbon ball/CF composite film reached −45 dB at a thickness of 2.6 mm, and the EAB reached 3.2 GHz. The theoretical characterization results jointly prove the reason for the improved performance, and this study provides an experimental basis for a more in-depth exploration of the birth of new absorbing materials.

Fabrication of graphene-based magnetic carbon composites derived from iron cobalt metal-organic framework as dual-band electromagnetic wave absorbers

The fabrication of advanced magnetic carbon electromagnetic wave (EMW) absorbers derived from metal-organic framework (MOF) with thin thickness, wide bandwidth, strong absorption strength and low filling ratio remains a huge challenge. In this paper, CoFe2O4/CoFe/C/Graphene composites were prepared by a simple two-step way of solvothermal reaction and carbonization treatment. The results of micromorphology analysis revealed that as the carbonization temperature increased, the obtained carbon frameworks changed from a spindle shape to dodecahedron-like shape and finally to a tile shape, and the carbonization temperature had a notable influence on the electromagnetic parameters and EMW absorption properties of the magnetic carbon composites. It should be noted that the obtained CoFe2O4/CoFe/C/Graphene composites exhibited comprehensive excellent EMW absorption performance when the carbonization temperature was 750.0 ℃ and the filling radio was only 15.0 wt%, namely the effective absorption bandwidth reached up to 4.8 GHz and the optimal minimum reflection loss was −40.2 dB at a thickness of 2.06 mm. A distinct dual-band (C band and Ku band) absorption feature was observed when the thickness exceeded or equaled 4.5 mm. Furthermore, the underlying electromagnetic dissipation mechanisms were also elucidated. Therefore, our results could provide a valuable reference for preparing excellent magnetic carbon EMW absorbers derived from MOF.

Fast Joule Heating for the Scalable and Green Production of Graphene with a High Surface Area.

The rapid development of electric vehicles, unmanned aerial vehicles, and wearable electronic devices has led to great interest in research related to the synthesis of graphene with a high specific surface area for energy applications. However, the problem of graphene synthesis scalability, as well as the lengthy duration and high energy intensity of the activation processes of carbon materials, are significant disadvantages. In this study, a novel reactor was developed for the green, simple, and scalable electrochemical synthesis of graphene oxide with a low oxygen content of 14.1%. The resulting material was activated using the fast joule heating method. The processing of mildly oxidized graphene with a high-energy short electrical pulse (32 ms) made it possible to obtain a graphene-based porous carbon material with a specific surface area of up to 1984.5 m2/g. The increase in the specific surface area was attributed to the rupture of the original graphene flakes into smaller particles due to the explosive release of gaseous products. In addition, joule heating was able to instantly reduce the oxidized graphene and decrease its electrical resistance from >10 MΩ/sq to 20 Ω/sq due to sp2 carbon structure regeneration, as confirmed by Raman spectroscopy. The low energy intensity, simplicity, and use of environment-friendly chemicals rendered the proposed method scalable. The resulting graphene material with a high surface area and conductivity can be used in various energy applications, such as Li-ion batteries and supercapacitors.

Fabrication and optimization of activated carbon-based graphene oxide from rice husks as an alternative to graphite

Processing of renewable, abundant, and low-cost biomass into graphene materials such as porous carbon materials for application in the environmental field, electronics and clean energy has been attracting interest in the last few decades.

Exploring green and efficient zero-dimensional carbon-based inhibitors for carbon steel: From performance to mechanism

Metal corrosion results in significant economic losses and poses potential safety problems. Graphene oxide (GO) is an innovative and effective corrosion inhibitor but suffers from a laborious and financially burdensome post-modification. Herein, zero-dimensional carbon-based graphene quantum dots without and with N doping (namely, GQDs and NGQDs) were synthesized without any post-modification, and innovatively served as a novel green, efficient corrosion inhibitor for carbon steel. Crucially, their inhibition mechanism and the inhibiting enhancement mechanism induced by N incorporation was comprehensively revealed. The results showed that in stark contrast to GO, GQDs and NGQDs without post-treatment possessed smaller sizes, much better monodispersity, and higher water solubility. And they displayed a remarkable inhibition efficiency (η) for carbon steel, which was comparable to the modified GO. Specifically, GQDs exhibited an η of 83.32% at a concentration of 200 mg/L, while NGQDs achieved an even higher η of 89.25%. As evidenced by the corrosion morphology investigation, adsorption isotherm analysis, and theoretical calculation, the inhibition mechanism of GQDs and NGQDs was attributed to their physical and chemical adsorption on the steel surface, hindering metal dissolution of the anode and hydrogen evolution of the cathode. Innovatively, density functional theory and molecular dynamics simulation elucidated the positive impact of N doping on the inhibition performance of NGQDs. That was N doping endowed NGQDs with better charge-donating ability, leading to stronger adsorption on the steel substrate than GQDs. This study not only contributed to addressing a critical need in the industry by presenting a viable environmentally friendly, low-cost, and efficient corrosion inhibitor, but also provided new insights for the development of corrosion inhibition theory.

Microporous carbon prepared by microwave pyrolysis of scrap tyres and the effect of K+ in its structure on xylene adsorption

This work brings novel information about microwave-assisted pyrolysis of scrap tyres, the industrial realization of which is still an engineering challenge due to both missing fundamental processing issues as well as how to enhance the engineering quality of pyrolytic products, mainly of solid carbon black. One-step microwave pyrolysis of scrap tyres for 50 min at power of 440 W with KOH activation in the mass ratio of 1:3 (scrap tyres:KOH) is successfully applied for the first time to yield micropores-containing carbon black which application potential was verified for xylene adsorption from waste gas. Compared to conventional high-temperature pyrolysis, the microwave pyrolysis requires shorter time and thus significantly reduces input energy. Two-step microwave pyrolysis of scrap tyres at 440 W does not result in more organized graphene-based carbon, but turbostratic carbon is more perturbed. The higher microwave power of 950 W within one-step microwave pyrolysis does not enhance the graphitization of carbon black, but shorten the microwave pyrolysis time to 20 min. The two main physicochemical properties of the novel micro-macroporous carbon black determining its adsorption performance for xylene are the microporosity/large volume of micropores and K+ present in the carbon structure. Micropores <0.52 nm with/without K+ and cavities <0.82 nm with K+ within carbon structure are proved by molecular modeling to be the sites with the highest affinity for xylene adsorption. Higher adsorption capacity of activated carbon blacks compared to non-activated ones correlates with molecular modeling results. More perturbed carbon structure does not affect the xylene adsorption.

Quantitative morphometry of topological graphene-based aerogels and carbon foams by x-ray micro-computed tomography

In this work, we report quantitative morphometry of freeze-dried graphene-based aerogels (i.e., graphene aerogel-GA, nitrogenated GA-NGA, graphene-carbon nanotube hybrid-Gr-MWCNTs, carbon foam-CF, and CF-GA hybrid-CF-GA) and monoliths, prepared by hydrothermal and organic sol-gel methods, respectively. X-ray micro-computed tomography (XMCT) in combination with scanning and transmission electron microscopy allowed visualization of internal microstructures in three-dimensional space. Quantitative morphometry analysis through the reconstructed volume renderings from two-dimensional sliced images revealed hierarchical structures possessing interlaced thin sheets, honeycomb organization, and topological interconnected pore background domains. The influence of small-diameter functionalized multi-walled carbon nanotubes (MWCNTs) inclusions to graphene-like sheets and integration with CF is assessed through quantitative morphometry analysis in terms of volume-weighted pore size, wall thickness, and porosity levels. Hybrid composite porous solids elucidated cross-linking reinforced by a homogeneous distribution of CNTs into complex sheets of GA and CF matrices. A consistent trend impacting porosity and interconnectedness was found following NGA ≥ GA &amp;gt; CF &amp;gt; Gr-MWCNT2:1 &amp;gt; CF-GA &amp;gt; Gr-MWCNT3:1 &amp;gt; Gr-MWCNT5:1, from XMCT image processing and analyses in corroboration with physical properties and reliability. The experimental results provide insights and guide the design of characteristic porous carbonaceous and graphene-based functional nanomaterials for energy sciences, environmental engineering, and fundamental reactive transport of fluids.

Environment-adaptive, anti-fatigue thermal interface graphene foam

The rapid development of high-power and high-frequency devices in electronics leads to the urgent demands for advanced thermal interface materials (TIMs) with both superior thermal conductivity and excellent structural stability. Many attempts have exploited the silicone-based TIMs with higher thermal conductive fillers, however, their structural stability remains challenging in some extreme conditions. Here we fabricate the carbon-based graphene foam roll (GFR) as flexible TIM by hydroplastic foaming (HPF) and interface strengthening methods. The enhanced interface bonding within GFR by impregnation of graphene oxide (GO) enables its superior structural integrity. It can keep mechanical stability after 10,000 cycles at a compressive strain of 60% and sustain high temperature up to 500 °C, which has never been realized in previous reports. We demonstrate the GFR-TIM not only achieves very high structural stability but also exhibits higher thermal conductivity (∼17.42 W/mK) than most commercial TIMs (5–10 W/mK). The GFR-TIM can serve as an efficient heat-dissipation component for the CPU and shows superior cooling efficiency compared to commercial TIMs. Our work provides an advanced graphene-based TIM with excellent environment-adaptive and anti-fatigue properties, broadening their application in extreme environments, such as hypersonic vehicles, high-throughput satellites and high-power radar systems.

Graphene with KI-modified pore structure and its electrochemical capacitors application

AbstractThe use of electrochemical capacitors is greatly limited by their poor volumetric energy density, and the key for improving it is to develop porous yet compact carbon materials. In recent years, the densification of porous carbons by capillary forces during drying has been used as a main method to balance the density and porosity of porous carbons for high volumetric performance. But there are still deficiencies in fine tuning the pore structure, which limits the compatibility of porous carbons with high-voltage ionic liquids. We report a KI-assisted method to prepare graphene-based porous carbons with high density and high capacitance. During the synthesis of the carbons, graphene oxide was dispersed in KI solutions with concentrations of 12.5-37.5 mmol/mL followed by hydrothermal treatment at 180 °C for 6 h. The obtained hydrogels were dried in 0.01 MPa of air at 60 °C for 72 h. By this procedure, KI was loaded into a matrix of compact graphene and formed crystals to suppress over shrinkage of pores during drying to produce densification and pseudo-capacitance. Electrochemical characterization of the resulting materials indicated that the ion-accessible surface area and pseudo-capacitance of the porous carbons were increased. The KI/graphene composite with an optimum concentration of KI of 25 mmol/mL achieved both a high electrode density of 0.96 g cm-3 and a high volumetric capacitance of 115 F cm-3 (at 1 A g-1) in an ionic liquid electrolyte (1-alkyl-3-methylimidazolium tetrafluoroborate). A symmetric cell assembled using this material had a high volumetric energy density of 19.6 Wh L-1.

High Energy Density Lithium-Sulfur Batteries Based on Carbonaceous Two-Dimensional Additive Cathodes.

The increasing demand for electrical energy storage makes it essential to explore alternative battery chemistries that overcome the energy-density limitations of the current state-of-the-art lithium-ion batteries. In this scenario, lithium-sulfur batteries (LSBs) stand out due to the low cost, high theoretical capacity, and sustainability of sulfur. However, this battery technology presents several intrinsic limitations that need to be addressed in order to definitively achieve its commercialization. Herein, we report the fruitfulness of three different formulations using well-selected functional carbonaceous additives for sulfur cathode development, an in-house synthesized graphene-based porous carbon (ResFArGO), and a mixture of commercially available conductive carbons (CAs), as a facile and scalable strategy for the development of high-performing LSBs. The additives clearly improve the electrochemical properties of the sulfur electrodes due to an electronic conductivity enhancement, leading to an outstanding C-rate response with a remarkable capacity of 2 mA h cm-2 at 1C and superb capacities of 4.3, 4.0, and 3.6 mA h cm-2 at C/10 for ResFArGO10, ResFArGO5, and CAs, respectively. Moreover, in the case of ResFArGO, the presence of oxygen functional groups enables the development of compact high sulfur loading cathodes (>4 mgS cm-2) with a great ability to trap the soluble lithium polysulfides. Notably, the scalability of our system was further demonstrated by the assembly of prototype pouch cells delivering excellent capacities of 90 mA h (ResFArGO10 cell) and 70 mA h (ResFArGO5 and CAs cell) at C/10.

Enhanced electrochemical properties of graphene-based screen-printed carbon electrode by PPy modification: Experimental and DFT investigations

Here, a novel method to enhance the electrochemical properties of graphene-modified screen-printed carbon electrode (G/SPCE) with polypyrrole (PPy) nanosheets is proposed. The mechanism of improving the electrochemical sensitivity of G/SPCE was investigated at the molecular level. G/SPCE was modified with PPy nanosheets synthesized by oxidative polymerization to improve its electrochemical properties. The cyclic voltammetry (CV) and differential pulse voltammetry (DPV) response of PPy-modified G/SPCE (PPy/G/SPCE) to K3[Fe(CN)6] (PF) were tested experimentally. The results show that the oxidation current sensitivity of G/SPCE to PF after PPy nanosheets modification increased from 11.12 μA·mM−1 to 12.91 μA·mM−1 in CV response, and from 8.44 μA·mM−1 to 10.72 μA·mM−1 in DPV response. The effective reaction area of PPy/G/SPCE was found to be increased by scanning electron microscopy. And the functional group CO/CO in PPy/G/SPCE, acting as a catalyst for the redox reaction of PF, was also found to be improved by X-ray photoelectron spectroscopy. Furthermore, the adsorption energy, electron transfer and density of states changes of PF molecule on pure and PPy-modified graphene were analyzed based on density functional theory calculation. The calculation results show that the adsorption energy and electron transfer of PPy-modified graphene to PF molecule are significantly increased. The response sensitivity of graphene to PF molecule is greatly enhanced by the synergistic effect generated of PPy and graphene.

Oxygen Desorption by Graphene-Based Carbon Films Obtained Through Sublimation

Background: Nanocarbon materials are known as highly sensitive gas sensors when compared to common solid-state sensors. This manuscript discusses graphene-based carbon films as materials for a gas sensor operating at near room temperature. Methods: The structural characteristics of graphene-based carbon films on In2O3- and ITO- coated substrates were studied by confocal laser microscopy, SEM, and Raman spectroscopy. Microwave conductivity was measured by using a λ/4 coaxial resonator based on a symmetric two-wire line in the frequency range 0.65 - 1.2 GHz and the temperature range 290-360 K. Results: The results obtained showed that films on In2O3 - and ITO-coated substrates desorb oxygen from the various structural levels of graphene-based carbon, such as crystalline contacts between globular nanoparticles and distorted graphene fragments. A correlation between the size of nanoparticles in films and the desorption temperature was also revealed. Conclusion: Our studies have shown that thin films of natural graphene-based carbon are promising as gas sensors. The possibility of varying characteristic oxygen desorption temperatures on different substrates is discussed.

Effects of nano-particles on the MRR and TWR of graphene-based composite by EDM using copper tool

This experimental research graphene-based carbon fibre composite used as the workpiece and copper as tool electrode. Graphene-based carbon fibre composite used in aerospace, automotive, and other industries due to its lightweight and high strength-to-weight ratio. Four processing parameters—input current (Ip), voltage gap (Vg), pulse on time (Ton), and pulse off time (Toff) used to determined Material Removal Rate (MRR) and Tool Wear Rate (TWR) (TWR). In this work the influence of copper nanoparticles were investigated over the MRR and TWR. The design of experiments is based on standard L9 orthogonal array. 5.24% enhancement and 3.84% reduction were reported in the MRR and TWR, respectively, using the copper nanoparticle mixed dielectric compared to the simple dielectric oil.

Optimized single-step synthesis of graphene-based carbon nanosheets from palm oil fuel ash

Recycling palm oil fuel ash (POFA) into lucrative holey graphene nanosheets will not only save resources but will also prove to be a great solution to avoid the hazards of environmental pollution. The present research aims on studying the effects of temperature and ratio of potassium hydroxide (KOH) during the chemical activation reaction of POFA, resulting in porous graphene sheets with great scope in a variety of industrial applications. These two parameters were studied because of their major influence on the yield, surface area, porosity, and quality of the produced graphene sheets. Porous graphene sheets were prepared by optimizing different activation temperatures (700 °C, 800 °C, and 900 °C) and POFA to KOH impregnation ratios (1:2, 1:3, 1:4, and 1:5). The optimal conditions for producing the best POFA-derived holey graphene in terms of the number of layers, surface area, and porosity were found with impregnation ratio of 1:3 and at temperature of 800 °C. From scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HR-TEM) analyses, it was found that the resulting few layer nanosheets have more uniform porosity at these optimized conditions. We found Brunauer-Emmett-Teller (BET) surface area, pore volume and carbon percentage of 1506.64 m2/g, 0.88 cm3/g and 99% respectively which are comparable to the previous findings using other biomass sources. It was also found that a higher temperature and higher KOH ratio resulted into pore widening and increasing the surface area, but at temperatures beyond the optimized conditions, the surface area and pore volume were reduced due to more vigorous reactions, and volatilization, which led to pore destruction. The present work emphasizes that these parameters have major impact on POFA activation, and their optimisation resulted into good quality graphene nanosheets in a greener and sustainable way, which can be used for many applications including inexpensive energy-storage and water purification applications.