Applications Of Graphene Research Articles

Applicability of few layer graphene derived from annoni grass biomass on the mechanical properties of cement mortars

In this work, we report the potential applicability of few layer graphene (FLG) synthesized from annoni grass (AG) biomass (Eragrostis plana Nees) by investigating its impact on the flexural and compression strength of cement mortars. For this purpose the AG biomass was collected and burnt at the temperature of 400 °C per 60 min, obtaining the AG ash (AGA). For FLG production, the AGA was mixture with the chemical reagent potassium hydroxide (KOH) and burnt at the temperature and time of 850 °C and 60 min, respectively. For the mechanical properties analysis, a reference sample (A0-without FLG) and samples with different percentage of FLG were prepared, specifically 0.02 % (A1), 0.03 % (A2), 0.05 % (A3), 0.07 % (A4) and 0.1 % (A5). Statistical analysis (Analysis of Variance, ANOVA) of the mechanical properties demonstrates a maximum flexural and compression strength in sample A2. The flexural and compression strength increase 25.2 % and 10.1 % compared to the reference mortar. These results indicate that the FLG produced from AG not only improves the mechanical properties of mortars but also presents significant environmental benefits, because AG is considered an invasive pest of agricultural fields of the southern region of Brazil. Therefore, with its removal from the fields it would be contributing to environmental preservation.

Realizing single-layer graphene by simultaneous crystallization and top-down etching of amorphous graphene-like carbon obtained via CVD

Continuous large-area graphene can be obtained on copper by utilizing solid polymer carbon sources (SPCS). However, the detailed conversion process and related mechanisms have been rarely reported. Here, a low-temperature chemical vapor deposition (CVD) combined with high-temperature hydrogen annealing (HTHA) method is designed to investigate the intricate evolution process from SPCS to amorphous graphene-like carbon (AGLC), and subsequently to single-layer graphene (SLG). During low-temperature CVD process, under catalysis of copper and auxiliary catalysis of hydrogen, the pyrolysis products of SPCS undergo nucleation and growth on copper, resulting in the formation of AGLC at 500 °C. During subsequent HTHA process above 1000 °C, the conversion of AGLC to continuous SLG can be achieved through simultaneous catalytic crystallization of copper and top-down etching of hydrogen, which sequentially undergoes coexistence stage of AGLC/few-layer graphene (FLG), followed by FLG formation stage. Under different stage and conditions, there exists a synergistic-competitive relationship between catalytic effect of copper and etching effect of hydrogen. The proposed conversion mechanism can provide fundamental insights into SLG synthesis via SPCS, which could facilitate further advancements in large-scale industrial applications of graphene.

Advances in the Application of Graphene in Lithium-ion Batteries

The search for effective energy storage options has escalated due to the rising global energy demands and environmental concerns. Lithium-ion batteries (LIBs) emerge as a key technology. However, the performance of traditional LIBs still needs to be improved. Therefore, choosing new nanomaterials for the modification of LIBs has become an effective solution. Graphene, as a nanomaterial, is an excellent candidate material for modification. This paper delves into the application of graphene in enhancing the performance of LIBs. Graphene, with its superior electrical conductivity and substantial specific surface area, offers the potential to enhance the performance of both anode and cathode materials in LIBs. This can lead to significant improvements in the overall cycle life, energy density, and power density of these batteries. This work emphasizes the application of graphene in cathode and anode materials. In cathode materials, the layered structure of graphene enables lithium-ion with high theoretical capacity. Meanwhile, graphene helps improve the electron and lithium ion mobility of anode materials. Despite the promising developments, challenges such as lithium loading capacity and coulombic efficiency still remain. The continued exploration of graphene applications is expected to drive LIBs to unprecedented performance metrics. This is in line with the global quest for sustainable and efficient energy storage technologies.

Supercritical mechano-exfoliation process

The intricate balance among cost, output, and quality has substantially hindered the practical application of graphene within the downstream industry chain. Here we present a scalable and green supercritical CO2-assisted mechano-exfoliation (SCME) process that omits the use of organic solvents and oxidants throughout the production lifecycle, including exfoliation, separation, and purification. The SCME process achieves graphene powder space-time yields exceeding 40 kg/(m³·day) at laboratory (0.06–0.2 kg) and pilot scales ( > 4 kg), with resultant free-standing films showing conductivities up to 5.26 × 10⁵ S/m. Further kinetic investigations propose general guidelines for grinding-assisted exfoliation: (1) the macroscopic optimizing ability of mechanotechnics for mass transfer frequency and stress distribution and (2) the microscopic multiplication ability of exfoliation medium for shear-delamination. The comprehensive techno-economic analysis also underscores the economic viability of the SCME process for large-scale production.

Preparation Methods and Quantum Hall Effect of Graphene

Graphene is a two-dimensional ultra-thin functional material. It has the characteristics of light weight, and it exhibits stable chemical properties. In recent years, it has become an excellent candidate material for the modification of various functional devices due to its excellent electrical performance. The performance of graphene is significantly influenced by the preparation method. Therefore, it is necessary to summarize the preparation methods of graphene. In addition, these functional devices typically operate in complex external environments, including magnetic fields, temperature fields, and electric fields. Therefore, studying the quantum Hall effect of graphene is of great significance for the use of graphene based devices. This article is written in order to provide a quicker understanding of this field. The preparation methods of graphene are briefly described. Among these methods, several industrialized methods of graphene production are also highlighted. Then, the progresses of quantum Hall effect in graphene are also presented. This work is of great significance for promoting the application of graphene based devices in complex external field environments.

Graphene-Based Materials in Energy Storage and Conversion Devices

Global energy demand and environmental concerns have grown increasingly over the years. To solve these problems, advanced energy storage and conversion technologies are essential. This work explores the applications of graphene-based materials to enhance the performance of lithium-ion batteries, supercapacitors, and solar cells. In lithium-ion batteries, graphene significantly improves electrical conductivity, mechanical stability, and energy capacity, thereby improving battery performance. Likewise, in supercapacitors, graphene-based electrodes exhibit excellent specific capacitance and energy density, which are crucial for high-power applications. In solar cells, graphene improves photoelectric conversion efficiency and stability, especially in perovskite and ZnO/Si heterojunction solar cells. However, the high cost and complexity of producing graphene limit its widespread use. Future research should focus on developing cost-effective production methods, optimizing graphene properties through doping, exploring composite materials, and expanding graphene applications in sustainable energy and environmental fields. This work provides an overview of current progress and suggests directions for future research in this area.

Application of Graphene in Acoustoelectronics.

An interdigital transducer structure was fabricated from multilayer graphene on the surface of the YZ-cut of a LiNbO3 ferroelectric crystal. The multilayer graphene was prepared by CVD method and transferred onto the surface of the LiNbO3 substrate. The properties of the multilayer graphene film were studied by Raman spectroscopy. A multilayer graphene (MLG) interdigital transducer (IDT) structure for surface acoustic wave (SAW) excitation with a wavelength of Λ=60 μm was fabricated on the surface of the LiNbO3 crystal using electron beam lithography (EBL) and plasma chemical etching. The amplitude-frequency response of the SAW delay time line was measured. The process of SAW excitation by graphene IDT was visualized by scanning electron microscopy. It was demonstrated that the increase in the SAW velocity using graphene was related to the minimization of the IDT mass.

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.

Quantum dots applied in healthcare

This article addresses the applications of quantum dots in the health area, focusing on the applications of graphene and carbon dots. It also presents the explanation of what quantum dots are, and the motivation for using this technology in health. For this approach, research was carried out with sever-al authors, in order to present to the reader, the importance of further studies of this nanotechnology so that in the future it can be applied in the health network. It should be noted that only a portion of the studies already published on quantum dots and the health area have been addressed.

Graphene Coating and its Effect on Performance of Box Type Solar Cooker: An Experimental Investigation

Background: Solar cookers have been the subject of several theoretical and empirical investigations, with numerous modifications attempted to increase efficiency and security. Solar cookers need much sophisticated research and enhancement work to function better. A thorough grasp of the application of graphene in box-type solar cooking systems is crucial for both solar energy and graphene. Objective: To improve the performance of box-type solar cookers, this patent research aims to offer an experimental investigation and insightful information on of applying graphene coating to the absorber plate and its derivative. Materials and Methods: To ensure equal dispersion of graphene into the black paint, three samples containing (1, 3, and 5wt%) of graphene embedded with the paint were produced with 1mm, 3mm, and 5mm thickness of the coating and stirred at 400 rpm for two hours using a magnetic stirrer. Xray diffraction and scanning electron microscopy have been studied to comprehend the influence of graphene nanoparticles on the surface morphology of the coated absorber panel. Performance evaluations of the box-type solar cookers were conducted with and without a graphene coating on the absorber plate, and data has been recorded for each case. Results: The results of patent research show that the absorber plate with (1, 3, and 5wt.%) of graphene embedded with black paint 1mm, 3mm, and 5mm thickness coating has a maximum thermal efficiency of 41.48% with 97.08 W cooking power, 46% with 109.35 W cooking power, and 49% with 114.77 W cooking power for the average solar irradiation is 978 W/m2. Discussion: It was determined that the cooking power (P), the first figure of merit (F1), and the second figure of merit (F2) were all satisfactorily achieved. Embedding black paint into graphene coating has been shown to significantly influence the heat transmission and thermal performance enhancement of box-type solar cookers, as demonstrated by the findings of X-ray diffraction and Scanning Electron Microscopy analysis. Conclusion: The current research makes it abundantly evident that the incorporation of graphene into the absorber plate of a box-type solar cooker, together with the application of a black paint coating, leads to increased heat transfer rates, which in turn provides an increase in cooking power. Because of this, graphene is an attractive nanomaterial that has the potential to improve the performance of box-type solar cookers, which is the novelty of this research work.

Biocompatibility of Water-Dispersible Pristine Graphene and Graphene Oxide Using a Close-to-Human Animal Model: APilot Study on Swine.

Graphene-based materials (GBMs) are of considerable interest for biomedical applications, and the pilot study on the toxicological and immunological impact of pristine graphene (GR) and graphene oxide (GO) using swine as a close-to-human provides valuable insights. First, ex vivo experiments are conducted on swine blood cells, then GBMs are injected intraperitoneally (i.p.) into swine. Hematological and biochemical analyses at various intervals indicate that neither GO nor GR cause systemic inflammation, pro-coagulant responses, or renal or hepatic dysfunction. Importantly, no systemic toxicity is observed. Analysis of a panel of 84 immune-related genes shows minimal impact of GO and GR. The animals are sacrificed 21 days post-injection, and transient absorption imaging and Raman mapping show the presence of GO and GR in the mesentery only. Histological evaluation reveals no signs of alterations in other organs. Thus, clusters of both materials are detected in the mesentery, and GO aggregates are surrounded only by macrophages with the formation of granulomas. In contrast, modest local reactions are observed around the GR clusters. Overall, these results reveal that i.p. injection of GBMs resulted in a modest local tissue reaction without systemic toxicity. This study, performed in swine, provides essential guidance for future biomedical applications of graphene.

Recent Research Progress of Porous Graphene and Applications in Molecular Sieve, Sensor, and Supercapacitor.

Porous graphene, including 2D and 3D porous graphene, is widely researched recently. One of the most attractive features is the proper utilization of graphene defects, which combine the advantages of both graphene and porous materials, greatly enriching the applications of porous graphene in biology, chemistry, electronics, and other fields. In this review, the defects of graphene are first discussed to provide a comprehensive understanding of porous graphene. Then, the latest advancements in the preparation of 2D and 3D porous graphene are presented. The pros and cons of these preparation methods are discussed in detail, providing a direction for the fabrication of porous graphene. Moreover, various superior properties of porous graphene are described, laying the foundation for their promising applications. Owing to its abundant morphology, wide distribution of pore size, and remarkable properties benefited from porous structure, porous graphene can not only promote molecular diffusion and electron transfer but also expose more active sites. Consequently, a serious of applications containing gas sieving, liquid separation, sensors, and supercapacitors, are presented. Finally, the challenges confronted during preparation and characterization of porous graphene are discussed, offering guidance for the future development of porous graphene in fabrication, characterization, properties, and applications.

Study on preparation and properties of GA/h-BN modified road petroleum asphalt based on ball milling method

ABSTRACT Graphene (GA), a two-dimensional nanomaterial, is noted for its exceptional mechanical, thermal and electrical properties. The integration of GA with road materials can potentially develop high-performance composite road materials. However, its application in road engineering is limited by complex preparation processes and high costs. This paper presents a GA/h-BN composite material developed through mechanical stripping using flake graphite and hexagonal boron nitride (h-BN). A mathematical model was created employing uniform design methods and optimised through numerical analysis to identify the optimal process parameters. Microscopic techniques, including X-ray diffraction and atomic force microscopy, confirmed that the GA/h-BN product consists of approximately three layers, forming a ‘graphene-hexagonal boron nitride-graphene’ nanolayer structure. The composite was then used to modify matrix asphalt, with performance tests determining the optimal dosage. The results indicated that adding 0.3% GA/h-BN significantly improved the asphalt's high- and low-temperature performance, fatigue resistance and cracking resistance. Moreover, the evaluation of the physical properties of matrix asphalt modified solely with h-BN revealed that, despite h-BN comprising 70% of the mass fraction in the GA/h-BN modifier, it exerted a minimal impact on the performance of the asphalt. This study introduces a novel source of raw materials for the application of GA in road engineering.

Graphene Composites and its Application in Environmental Treatment

Graphene, as a new two-dimensional material, is an ideal material for pollutant adsorption because of its large specific surface area and strong adsorption capacity. Moreover, graphene has an ultra-high electron transport capacity and can be used as a carrier of photocatalysis to further treat pollutants, so it has a wide range of applications in the field of environmental governance. However, with the application of graphene in the field of environmental treatment, the shortcomings of graphene are gradually exposed, such as easy aggregation, easy oxidation and biological toxicity. In recent years, in order to better meet the needs of removing pollutants in the environment and solve the shortcomings of graphene, graphene composites came into being. In this paper, three kinds of graphene composites which can solve the problems of easy aggregation, easy oxidation and biological toxicity of graphene are found out from thousands of graphene composites, and the basic properties, preparation methods and applications in environmental treatment are summarized respectively. They are graphene/metal oxide composites, porous foam/graphene oxide composites and graphene oxide/chitosan composites. At the same time, the application of graphene composites in pollutant adsorption and degradation and the problems existing in this process are also introduced in detail.

Mode of application of sulfonated graphene modulated bioavailable heavy metal contents and microbial community composition in long-term heavy metal contaminated soil

Nanomaterials are increasingly recognized for their potential in soil remediation. However, their impact on soil microbial communities in contaminated soil remains poorly understood. In this study, we investigated the dynamic effects of sulfonated graphene (SG) following one-time or repeated applications on heavy metal availability and soil microbial communities in long-term heavy metal-contaminated soil over 180 days. Our findings revealed that one-time SG application at 30 mg kg−1 significantly increased the bioavailable cadmium (Cd) and copper (Cu) contents by approximately 30 %–40 % after 2 and 180 days. Repeated SG applications, however, displayed no significant influence on heavy metal availability. One-time SG application, coupled with the increased available Cd, induced significant enrichment of some specific functional bacterial genera involved in glycan biosynthesis metabolism and biosynthesis of other secondary metabolites, thereby decreasing the available contents of heavy metals after 90 days. However, the shifts in bacterial community structure and function were subsequently partially recovered after 180 days. Conversely, repeated SG treatments led to minimal alterations after 90 days while leading to similar shifts in the bacterial community at 60 mg kg−1 after 180 days. The fungal community structure remained largely unaltered across all SG treatments. Intriguingly, SG treatments substantially stimulated fungal biomass, with the stimulation degree dependent on SG dosage. These results provide valuable insights for developing phytoremediation strategies, suggesting tailored SG applications during specific growth phases to optimize remediation efficiency.

Green and energy-saving tread rubber by constructing chemical cross-linking interface between graphene oxide and natural rubber

The dispersibility of fillers and interfacial interaction are crucial for polymer nanocomposites. Developing a simple, efficient and green method to simultaneously reduce and functionalize graphene oxide (GO) for preparing graphene/rubber composites with excellent dispersibility and enhanced interfacial interactions remains one of the main trends in developing and expanding the application of graphene in the rubber industry. In this work, VOC (volatile organic compound) -free and environmentally friendly L-methionine (L-Met) was selected as the functional modifier of GO. Then, L-Met-modified GO (MGO) was blended with natural rubber (NR) in an aqueous phase to prepare MGO/NR composites. The amphiphilic property of L-Met not only reduced GO but also endowed it with less agglomeration and excellent water dispersibility, which was a prerequisite for achieving uniform dispersion of GO in the NR matrix. In addition, the amino acids on the surface of MGO enhanced the compatibility between GO and the protein-phospholipid layer on the outer layer of NR latex particles. Meanwhile, L-Met containing sulfur bonds promoted rubber vulcanization, resulting in the formation of a cross-linked network between the modified GO and NR molecular chains. Compared to unmodified GO/NR composites, MGO/NR composites exhibited excellent mechanical properties and low heat build-up. More importantly, the solid tire prepared by using L-Met as the interface modifier for GO filled rubber showed lower rolling resistance and temperature rise, and the energy saving efficiency was improved. This strategy is expected to provide a new insight into the green production of organically modified graphene and the preparation of low-energy-consumption green graphene tires.

Fluid-Dynamics-Rectified Chemical Vapor Deposition (CVD) Preparing Graphene-Skinned Glass Fiber Fabric and Its Application in Natural Energy Harvest.

Graphene chemical vapor deposition (CVD) growth directly on target using substrates presents a significant route toward graphene applications. However, the substrates are usually catalytic-inert and special-shaped; thus, large-scale, high-uniformity, and high-quality graphene growth is challenging. Herein, graphene-skinned glass fiber fabric (GGFF) was developed through graphene CVD growth on glass fiber fabric, a Widely used engineering material. A fluid dynamics rectification strategy was first proposed to synergistically regulate the distribution of carbon species in 3D space and their collisions with hierarchical-structured substrates, through which highly uniform deposition of high-quality graphene on fibers in large-scale 3D-woven fabric was realized. This strategy is universal and applicable to CVD systems using various carbon precursors. GGFF exhibits high electrical conductivity and photothermal conversion capability, based on which a natural energy harvester was first developed. It can harvest both solar and raindrop energy through solar heating and droplet-based electricity generating, presenting promising potentials to alleviate energy burdens.

Effect and mechanisms of type, content, and dispersion method of flash graphene on the rheological behaviors of fresh cement pastes

Flash Joule heating provides a facile, low-carbon, and cost-effective method for upscale graphene production, benefiting the application of graphene in modifying cement-based materials. Understanding the effect and mechanisms of flash graphene (FG) type, content, and dispersion method on the rheological behaviors of cement-based materials is essential for designing and controlling cement-based materials in different application scenarios. Therefore, this study explored the rheological behaviors of cement pastes with 2 different types of flash graphene at 4 different content levels (namely 0.1 wt%, 0.2 wt%, 0.3 wt%, and 0.4 wt% of cement mass) using 3 different dispersion methods (namely water reducer dispersion with ultrasonic treatment, dry mixing with water reducer, and mechanical dispersion with water reducer). The results indicated that the addition of FG generally increases the yield stress and plastic viscosity of fresh cement pastes. The water reducer dispersion with ultrasonic treatment and nano-boron doping shows a good effect in dispersing FG. The influence mechanisms of FG on rheological behaviors of fresh cement pastes are a competition between exert replacement, agglomeration, lubrication, and adsorption effects.

Unveiling the Versatile Applications of Cobalt Oxide-Embedded Nitrogen-Doped Porous Graphene for Enhanced Energy Storage and Simultaneous Determination of Ascorbic Acid, Dopamine and Uric Acid

The advancement of electrode materials is essential for addressing the energy and biomedical challenges. A multi-functional approach was employed to create a new electrode material of cobalt oxide-embedded nitrogen-doped porous graphene (Co3O4@NpG) for sensing and energy storage applications. In the present study, we have fabricated a new electrochemical sensing platform based on Co3O4@NpG. The sensing performance and selective detection capability of the demonstrated sensor was optimized and tested by determining dopamine (DA), uric acid (UA), and ascorbic acid (AA) simultaneously in analyte fortified biological samples. The sensing response is noticed to be linearly dependent upon the concentration of AA, DA, and UA in the range of 0.1–450, 0.1–502, and 0.2–396 μM, respectively. This material also showed good electrochemical energy storage performance when assessed as a supercapacitor electrode. The Co3O4@NpG electrode material showcased a remarkable specific capacitance of 314.58 Fg−1, an energy density of 10.06 Wh kg−1 at a power density of 240 Wkg−1 at 0.5 Ag−1, in a 6 M KOH electrolyte, along with excellent long-term cycling stability. Hence, the material Co3O4@NpG stands out as a promising multifunctional electrode candidate, excelling in the precise simultaneous detection of critical biomolecules besides exhibiting superior energy storage performance.

Chemical vapor deposition and applications of vertical graphene: Progress and prospects

Chemical vapor deposition and applications of vertical graphene: Progress and prospects