Graphene Sheets Research Articles

Hydrothermal-based controllable synthesis and structural-optical characterization of 2D-MoS2/graphene nanocomposites for optoelectronic applications

This study presents a two-dimensional (2D) nanocomposite of molybdenum disulfide/graphene (2D-MoS2/C) synthesized via a hydrothermal method at 230 °C for 2 h. Comprehensive characterization using XRD, FESEM, HRTEM, Raman spectroscopy, XPS, UV–Vis spectroscopy, and PL measurements revealed detailed microstructural, morphological, compositional, and optical properties. FESEM confirmed the uniform crystallization of ultrathin 2D MoS2 nanocrystals on graphene sheets, while TEM and HRTEM showed vertical growth of 2D MoS2 nanosheets (∼3–6 nm thick), forming a 2D MoS2/C architecture. XRD and Raman analyses verified the hexagonal 2H–MoS2 phase with minimal impurities, supported by XPS measurement. MicroRaman analysis indicated defect repair in graphene oxide substrate, evidenced by reduced D-band intensity and an enhanced 2D-band. The 2D MoS2/C nanocomposite exhibited significant photoluminescence with distinct emission peaks in the visible range (∼1.75–2.05 eV), surpassing the 2D MoS2 counterpart. Notably, 2D MoS2/C thin films showed high absorbance (∼83 %) compared to graphene oxide (∼48.4 %) and bare 2D MoS2 (∼22.1 %), highlighting enhanced light-matter interaction. This straightforward, cost-effective synthesis approach offers promising potential for MoS2/C nanocomposite applications in optoelectronics and catalysis.

Tribological manufacturing of ZDDP tribofilms functionalised by graphene nanoplatelets

Abstract 3D Tribo-Nanoprinting (3D TNP), which uses a highly controllable tribological contact to deposit tribofilms, has been proposed as a manufacturing method for nanoscale structures. Inspired by this, we show for the first time, as a proof of concept, the ability to electrically functionalise tribofilms for potential use in the manufacture of structures with nanoscale thickness. Zinc dialkyldithiophosphate (ZDDP) tribofilms have been generated to include varying concentrations of graphene nanoplatelets (GNPs) resulting in them becoming electrically conductive when tested using conductive atomic force microscopy. In its highest GNP concentration, approximately 55% of the surface of the tribofilm was able to sustain current up to a threshold of 245 pA. The higher graphene content led to a suppression in film formation and decreased substrate coverage. Transmission electron microscopy revealed a dual-layered tribofilm with a carbon-rich layer above a pure layer of ZDDP tribofilm. Within the carbon-rich layer, the GNPs formed into scrolls which created an internal network through which current could flow, being limited by the insulating pure ZDDP layer at the film-substrate interface, and the presence of surface graphene sheets. A modified lateral force microscopy procedure supported the presence of surface graphene sheets. Despite limited deposition precision in terms of homogeneity and distribution of the tribofilms, this work provides a step towards the use of 3D TNP for the manufacture of electronic structures on the nanoscale by proving that tribofilms can be functionalised by the addition of particle additives.

Highly efficient and responsive thin heaters based on CVD graphene/polyetherimide nanolaminates for next-gen thermal management applications

Graphene, with its superior physical properties, has been considered as the perfect candidate for the production of lightweight, high-strength composite materials with interesting multi-functionalities. The use of large-sized, high-quality CVD graphene monolayers alternated to ultra-thin polymer films in a laminate configuration has been recently proposed as an efficient route to overcome many of the limitations faced by the use of discontinuous sheets of graphene in nanocomposites. Here we report on the production of CVD graphene/polyetherimide (Gr/PEI) nanolaminates with very low graphene volume fractions (up to 0.165 vol%), using a modified iterative and automatic lift-off/float-on procedure. The produced freestanding Gr/PEI nanolaminates present not only a significant enhancement of mechanical and electrical properties but, very interestingly, show impressive Joule heating efficiency. In fact, upon the application of an electrical potential, they can reach temperatures higher than 250 °C, with heating rates up to 325 °C/s. The produced heaters show a very uniform distribution of the temperature even when bend and are characterized by low power consumptions (up to 16 Watt) and high areal power densities (up to ca. ∼1.28 W/cm2), thus suggesting their possible application in thermal management.

(Invited) Developing a Graphene Field-Effect Biosensor for Genetic Biomarkers: Simulations Unveil How the Device Sensitivity Is Related to DNA-Graphene Interactions at the Nanoscale

Graphene field-effect transistor biosensors (GFETs) offer a promising platform to detect cancer DNA biomarkers at low concentration [1]. At their core, they have an electronic circuit containing a graphene sheet – a two-dimensional nanomaterial made of a single layer of carbon atoms – whose electronic properties are very sensitive to nearby electric charges. Leveraging that feature, the electrical current generated by a GFET can thus be made very sensitive to the concentration of a specific DNA sequence in a biological sample. To achieve this, the complementary DNA sequence is linked to the graphene to bind specifically the target DNA. In most GFETs, the link is done using 1-pyrenebutanoic acid succinimidyl ester (PBASE) because its pyrene group stacks on the graphene through pi-pi interactions, without disrupting the electronic properties of the graphene. However, recent experiments in the Bouilly group have shown variations in GFET sensitivity depending on the incubation time of graphene with PBASE.Here, we use a computational approach developed in our previous work [2] to investigate at the nanoscale the role of PBASE linker molecules on the sensitivity of the GFET. First, we use molecular dynamics simulations to characterize the conformational ensemble of a 10-nt single-stranded DNA sequence linked to a graphene sheet using PBASE. Second, we estimate the electrical response of the GFET from the electrostatic potential generated by these DNA conformations on the graphene, as determined using electrostatic Poisson-Boltzmann simulations. Our results show that the conformational ensemble of DNA is strongly affected by the presence of other PBASE adsorbed on the graphene, thus changing the electrostatic potential generated on the graphene. The predicted change of the electrostatic potential should impact measurably the detection signal of the GFET.We are now using these simulations to explain the experimental characterizations of a GFET designed to detect a genetic biomarker important in breast cancer profiling. Our simulations have the potential to support the development of GFETs with better sensitivity for DNA detection.[1] Béraud, A., Sauvage, M., Bazán, C. M., Tie, M., Bencherif, A., and Bouilly, D. (2021) Graphene field-effect transistors as bioanalytical sensors: design, operation and performance. Analyst. 146:403-428.[2] Côté, S., Mousseau, N., and Bouilly, D. (2022) The molecular origin of the electrostatic gating of single-molecule field-effect biosensors investigated by molecular dynamics simulations. Phys. Chem. Chem. Phys. 24:4174-4186.

Effective Non-Precious Metal Oxide Supported Carbon as a High Performance Bifunctional Electrocatalyst for All Vanadium Redox Flow Batteries

As one of the most promising electrochemical energy storage systems, vanadium redox flow batteries (VRFBs) have received increasing attention owing to their attractive features for large-scale storage applications. However, their high production cost and relatively low energy efficiency still limit their feasibility. One of the critical components of VRFBs that can significantly influence the effectiveness and final cost is the electrode. Therefore, the development of an ideal electrocatalyst with low cost, large active surface area, good chemical stability, and excellent electrochemical activity toward the VO2+/VO2 + and V2+/V3+ redox reactions is essential for the design of VRFBs. Hence, we prepared a stable, high catalytic activity and uniformly distributed non-precious metal oxide nanoparticles on the surface graphene sheets via two step routes, hydrothermal followed by annealing at optimum temperature for VRFB applications. Among the samples, the prepared electrocatalyst shows the best electrochemical activity with lowest peak potential separation and highest peak current density toward VO2 +/VO2+ and V2+/V3+ redox reactions. This observation is due to the synergistic effects related to the presence of excess oxygen vacancies on the metal oxide, the high content of oxygen functional groups, and the high electrical conductivity of the graphene sheets. Hence, the prepared electrocatalyst grown on the surface of graphite felt (GF) support demonstrates the optimal electrochemical activity with the energy and voltage efficiencies of 76.8% and 80.9%, respectively, which are much greater than those of the 59.8% and 63.2% attained from pristine GF at 100 mA cm–2. Moreover, the electrode presented good stability and durability in acidic electrolyte during long-term operations for 100 cycles at a higher current density of 100 mA cm–2.

Impact of Water-Water Correlation at Suspended Graphene/Water Interface Under Different Electro-Modulated

Graphene-based devices have extensive applications in aqueous environments. The molecular interactions across the graphene sheet significantly impact various devices, although few researches focused on elucidating the interface effects. In this study, we utilize trench structure to make graphene unilaterally and bilaterally suspended in water. The conduction status of both lateral and longitudinal currents (Id, Is, Ig) of graphene was monitored under two suspension scenarios to investigate the changes in interface evolution with the introduction of solvent-solvent interactions. For unilaterally suspended graphene, the current perpendicular to the graphene channel direction remains in the off state. For bilaterally suspended graphene, the current path is formed vertically between the graphene channel and the gate electrode, perpendicular to the direction of the graphene. This experimental setup illustrates the possibilities for exploring interfacial characteristics at the interface between 2D materials and solutions through practical experimentation.The detailed fabrication process of the graphene field-effect-transistor (GFET) device is depicted in Fig. 1. To fabricate the microchannel structure, a microfluidic pattern was generated through photolithography on the SiO2/Si substrate spun with a layer of photoresist. Then, the corresponding microchannel pattern with a thickness of 300 nm SiO2 and 30 μm Si layer was etched by reactive-ion etching (RIE) to form a trench capable of storing water. Afterward, Au electrodes were placed next to the microfluidic channel via evaporation utilizing a shadow mask. The second critical step involves the preparation of graphene. Graphene sheets were grown on a copper foil through the chemical vapor deposition (CVD) method. With the support of PMMA film, physically stacked graphene bilayer graphene was transferred to the target substrate. Ultimately, the suspended bilayer graphene was submerged in acetone for 24 hours to remove the PMMA layer and immersed in isopropanol (IPA) and DI water to clean the residues.According to this device structure, we successfully fabricate the suspension of graphene unilaterally or bilaterally in water. When introducing water through the trench, the bottom surface of the suspended graphene contacts with water molecules, while the upper surface of the suspended graphene is exposed to air. This configuration leads to a unilateral suspension in water (unilateral-suspension GFET). Conversely, when water is introduced through the trench and water is also added above the graphene channel, graphene comes into contact with water on both sides. This configuration results in its bilateral suspension in the water (bilateral-suspension GFET). The electronic transport characteristics of unilateral-suspension GFET and bilateral-suspension GFET were measured by Agilent semiconductor analysis B1500A. The gate voltage was applied to water through an Ag/AgCl electrode. Fig. 2 (a) displays the Raman spectroscopy of suspended graphene on GFET device. The most notable features of the Raman spectrum are the G peak around 1580 cm-1, and the 2D band around 2700 cm-1, which are typical characteristics of graphene. The ID/IG ratio of 0.19 indicates the good quality of the graphene layers. As shown in Fig. 2 (b), the scanning electron microscope (SEM) result of suspended graphene on the GFET device verifies the presence of large-area graphene. The diagram displays a clear demarcation line, facilitating the identification of graphene presence on the substrate. This can also imply the excellent quality of graphene with few defects.The transport behavior of unilateral-suspension GFET and bilateral-suspension GFET are measured individually, as shown in Fig. 3. The sum (ΔI) of The drain current behavior (Id) and source current behavior (Is), and gate current behavior (Ig) are recorded with changed gate voltages (from -1V to +1V) and constant VDS (VDS= 0.1V). For unilateral-suspension GFET, ΔI and Ig keep constant at zero, and there is no conduction path perpendicular to the graphene channel direction. For bilateral-suspension GFET, ΔI and Ig at positive gate voltage are opposite in direction and equal in absolute value, this indicates the formation of an obvious path between the channel and gate electrode. The apparent interfacial evolution is believed to change with the introduction of the other side of water.In conclusion, we compare the electrical characteristics shown by two different suspension situations of graphene-based field effect transistors. There are some interesting results of the conduction path relating to interfacial evolution. This result has potential for chemical sensing or battery application. Furthermore, it can contribute to fundamental research about the interface interaction between suspended graphene and water. Figure 1

Synthesis and Modular Engineering of Porous Graphene Nanoarchitectures

Bottom-up nanoarchitectonics has demonstrated the capability to control structural parameters of nanomaterials with atomic precision. The surface-assisted synthesis of graphene-based one-dimensional nanostructures à la carte distinctly illustrates the power of this concept. However, despite impressive advances in the synthesis of 1D homostructures, advancing in structural complexity faces major challenges. However, despite impressive advances in the synthesis of 1D homostructures, advancing in structural complexity faces major challenges. The functionalization of edges in nanorib-bons, an effective strategy to tailor their electronic properties and chemical interactions, is a clear example. The concept of inserting the desired functional groups or dopants in the molecular precursor often fails due to their lack of stability during the reaction path. The fabrication of heterostructures is a second example, where the challenge lies on the control of the size and distribution of their com-ponents. A third one is extending the on-surface strategy to two-dimensional structures, where examples of long-range ordered nanoarchitectures are very limited.In this talk I will present different strategies that we have developed to overcome each one of this challenges. I will show introducing our method to synthesize a 2D nanoporous graphene, where the long-range order is achieved by the sequential growth of 1D building blocks and their posterior coupling [1]. I will continue presenting two modular strategies that lead to more complex nanoporous structures. The first consist on the molecular engineering of the coupling bridges. I will show an example where the introduction of phenyl groups in the bridges brings tunability of the quantum electronic coupling and the corresponding in-plane electronic anisotropy [2]. In a final example I will focus on intercalating different 1D ribbon components in periodic arrays for the formation of lateral heterostructure superlattices where the junction is defined with atomic precision [3]. One of the components being a N-doped ribbon, the heterostructure can also be seen as a nanoporous graphene sheet bearing N-doped pores.

Surface area and porosity analysis in nanoporous carbons by atomistic pore domain model

We present a new atomistic model for evaluating the surface area and porosity of micro-mesoporous carbons. This method, referred to as the atomistic pore domain model (APDM), advances the adsorption porosity methodology by calculating textural properties of micro-mesoporous carbons without relying on assumptions about pore geometry. A thorough analysis of porosity across eleven porous carbons demonstrates a robust correlation between the surface area accessible to N2 molecules, as computed using APDM and the Brunauer-Emmett-Teller method with Rouquerol criterium. This correlation is observed across a spectrum of nanoporous carbons, ranging from ultramicroporous activated carbon fibers and nanoporous carbon beads to supermicro-mesoporous activated carbons and activated carbon fibers. APDM facilitates the extraction of the information regarding the N2 surface area accessibility and the intrinsic geometric surface area of micro-mesoporous carbons. The N2-to-He surface area accessibility ratio of the investigated porous carbons varies from approximately 57 %–94 %, indicating varying degrees of pore sieving among studied carbon samples. Except for ACF-25 micro-mesoporous activated carbon fiber, the intrinsic geometric surface areas of the studied micro-mesoporous carbons are smaller than the geometrical surface area of a single graphene sheet (2640 m2/g).

Synthesis and characterization of zinc ferrite nanoparticles@GO for the photocatalytic degradation of Methylene Blue dye under visible light

Due to rising environmental pollution, there has been a growing focus on photo degradation catalysts for pollution removal. Under visible light irradiation, methylene blue dye (MB) photocatalytic degradation has been studied using Zinc ferrite nanoparticles (ZnFe2O4 NPs) and Zinc ferrite nanoparticles/graphene oxide (ZnFe2O4/GO). Methylene blue dye is a carcinogenic pollutant that poses risks to both humans and marine life. The synthesis of ZnFe2O4/GO was achieved by the biotemplating method. Synthesized nanoparticles were loaded on graphene oxide (GO) in different ratios (Zn1:GO1, Zn1:GO3, and Zn1:GO5). Nanocomposite characterization was done utilizing Raman Spectroscopy analysis, FT–IR, XRD, BET, FE-SEM–EDX, XPS, and TEM. The confirmation of the cubic spinel structure of ZnFe2O4 NPs has been validated uniformly distributed on the surface of the GO sheets. The vigorous interaction between ZnFe2O4 NPs and graphene sheets facilitates rapid electron mobility, enhancing electron separation and holes in photocatalytic applications. The aforementioned parameters are crucial in MB’s photocatalytic degradation performance. Photocatalytic degradation processes depend on pH solution, initial dye concentration, and catalyst dosage. The outcomes demonstrated that augmenting the proportion of graphene oxide amplified MB photo degradation. Under the optimum conditions of 1 g/L dose, pH 8, 10 mg/L initial dye concentration, and 180-min irradiation time, the degradation ratio increased to 51.17 %, 59.70 %, 89.49 %, and 97.38 % using ZnFe2O4, Zn1:GO1, Zn1:GO3, and Zn1:GO5, respectively. Based on the photo degradation process, GO exhibited superior photocatalytic performance at the highest concentration. The kinetics data showed that the photo degradation reaction adheres to the pseudo-second-order. The study indicated that the eco-friendly, non-toxic photocatalyst ZnFe2O4/GO can be used as an effective potential substance for water treatment as well as the elimination of hazardous organic dyes from aqueous solutions.

Enhancement of capillary flow via precursor film thickening in graphene nanochannels

The wicking dynamics of total wetting liquids in a nanocapillary differ from those of partial wetting liquids due to the presence of the precursor film. In this work, the wetting behavior of total wetting liquids (isopropyl alcohol and dimethylformamide) on graphene sheets, as well as the imbibition dynamics in graphene-based nanoslits, are investigated using molecular dynamics. The spontaneous spreading dynamics can be described by two power laws, with the long-term behavior conforming to the viscosity-dominated Tanner’s law. The imbibition behavior within nanoslits shows a deviation from Washburn’s equation, displaying a unique two-stage pattern. This pattern is marked by a turning point that is related to the type of liquid and is independent of the channel width. Notably, the imbibition rate in the second stage exceeds that in the first. The advancing rate of the precursor film is insensitive to changes in channel width. After the precursor film reaches the end of the channel, the second stage commences, followed by the re-thickening of the film. This re-thickening reduces the curvature radius of the meniscus and increases the driving Laplace pressure, thereby enhancing the capillary flow in the second stage.

Strong MXene-bridged graphene sheets for compact energy storage

Strong MXene-bridged graphene sheets for compact energy storage

Hydrogen storage capacity on vanadium decorated graphene

In the present study we performed Density Functional Theory (DFT) calculations to study the decorated Vanadium (V) on graphene sheet (Gr-V) as well. We adsorbed 6H2 molecules on V decorated graphene surface. The calculated total energy (Etotal) for pristine graphene and complex system Gr-V found –223.718 Ry and −368.95557 Ry respectively. After successive adsorption of molecular hydrogen, the total energy found in the range of −371.308 Ry to −382.523 Ry. We investigated the Fermi energy in increasing order within the range of 0.898 eV to 3.135 eV, The evaluated binding and Fermi energies confirms the Vanadium candidate is more suitable for hydrogen storage capacity of the studied system. On the basis of the extracted results, we can infer that the decorated hydrogen molecule (1H2-6H2) has the sufficient gravimetric capacity of V decorated graphene. The density of states (DOS) confirms the weak interaction between σ bonding electrons of H2 molecule (1H2-6H2) with the vanadium (V) decorated graphene complex system. Our reported complex system (Gr-V-1H2-6H2) is feasible for a promising material to store hydrogen molecules (H2) moreover.

Tunable terahertz filter based on graphene photonic crystals with defective layers

In this paper, we design a high-precision tunable terahertz filter by using transfer matrix method. The filter structure mainly consists of graphene embedded photonic crystals (GPCs). The front part of the GPCs contains artificial synthetic material and air layer, the back part of the GPCs is composed by and periodic stack of isotropic dielectric slabs (MgF2) embedded with graphene sheets, where air defect layer is located in the middle of the GPC as a central layer. Our simulation reveals that graphene layer and air defective layer strongly affect the filter performance. And we can get a relatively pure transmission peak in a wide frequency region. Additionally, the influence of incidence angle of terahertz wave, thickness of air layer, the unit number of front periodic structure and chemical potential of the graphene sheets can also modulate the function of the filter. And the filter has strong stability when the temperature changes from 150 K to 350 K.The results indicate that single channel, dual and multiple channels filter in a narrow frequency can be obtained by optimizing the structure parameter.

Damping Characteristics of Nonlocal Strain Gradient Waves in Thermoviscoelastic Graphene Sheets Subjected to Nonlinear Substrate Effects

Damping Characteristics of Nonlocal Strain Gradient Waves in Thermoviscoelastic Graphene Sheets Subjected to Nonlinear Substrate Effects

ZIF-67 Nanostructures Anchored on 3D Graphene Sheets: A Non-noble Electrocatalyst for Efficient Oxygen Evolution Reaction

ZIF-67 Nanostructures Anchored on 3D Graphene Sheets: A Non-noble Electrocatalyst for Efficient Oxygen Evolution Reaction

Synergistic integration of nickel, porous silicon, and thermally reduced graphene oxide for solid‐state hydrogen energy storage

AbstractSolid‐state hydrogen storage using metal hydrides offers the potential for high energy storage capacities. However, the requirement for high‐temperature operations (above 400°C) and challenges with heat exchange are significant drawbacks. From this perspective, adsorption on porous materials presents a viable solution to these challenges. Carbon nanostructures, such as graphene and graphene oxide (GO) derivatives, are well‐suited for hydrogen storage because of their lightweight nature, low density, and large surface area. However, the primary obstacle for practical applications is the poor storage capacity of carbon nanostructures under ambient conditions. Utilizing a cost‐effective transition element such as nickel as a catalyst offers significant potential for storing hydrogen in atomic and molecular forms by invoking the spillover mechanism. Thermally reduced graphene oxide (TrGO) modifies the surface, providing abundant active sites that attract hydrogen effectively. Porous silicon (PS) enhances the surface properties of graphene sheets, attracting hydrogen to the surface. The current study assesses a synthesized TrGO, PS, and Ni composition to leverage their individual properties for hydrogen storage. Field‐emission scanning electron microscopy examines the sheet structure of TrGO (used as the host material) and the incorporation of PS and Ni on its surface. The calculated specific surface area of TrGO is ~450 m2 g−1. X‐ray diffraction is used to identify the various phases in the composition, while Raman spectroscopy measures the degree of disorder within the composition. The pressure‐composition isotherms reveal hydrogen storage capacities of ~6.53 wt% for the TrGO + PS composition and ~2.43 wt% for the TrGO + PS + Ni composition. Despite the decrease in weight percentage of TrGO + PS + Ni due to the higher Ni content, dissociation enhances the adsorption rate from 0.35 to 0.53 wt% h−1.

Dual-function hollow MoS2 nanocages decorated on graphene sheets as efficient sulfur hosts for advanced lithium-sulfur batteries

Due to the presence of polysulfitabde shuttling, serious electrode expansion, and the low electrical conductivity of sulfur materials at room temperature, the commercialization of Li-S batteries is still not feasible. In this study, we have synthesized unique hollow molybdenum disulfide nanocages/reduced graphene oxide (H-MoS2/rGO) composites to be employed as highly effective cathodes for Li-S batteries. In this well-designed structure, the hollow MoS2 nanocages are tightly bound by C-O-Mo bonds and uniformly distributed across the graphene sheets. The dual-function MoS2 nanocages can adsorb polysulfides by Mo-S bond and accelerate the conversion reaction of S8 and Li2S. Moreover, the 3D rGO network with abundant pores effectively reduces the diffusion path and enhances the rapid transport of electrons and ions. The hybrid H-MoS2/rGO cathodes with these advantages exhibit a remarkable initial discharge capacity of 801.7 mAh g−1 at 1 C, as well as a high specific discharge capacity of 533.2 mAh g−1 is remained over 500 cycles.

Emerging flat bands and spin polarization in nanodiamond island superlattices with varying carrier effective masses

For the first time, a set of regular 2D sp2/sp3 hybrid superlattices of nanodiamond islands confined between two graphene sheets (NDI-c2G) were proposed and explored using Density Functional Theory Periodic Boundary Conditions simulations. The fusion involves coronene and ovalene molecules with top and bottom graphene lattices, which can be treated with electron beam irradiation and atomic hydrogen at the nanodiamond site in three different configurations: (111)CD, (0001)HD, and (2¯110)HD. This creates distorted sp3 nanodiamond sublattices within the sp2 graphene fragments, serving as regions with confined electrons, making the charge carriers’ effective masses heavier. The presence of spin-splitting valence spin-up and conduction spin-down flat bands near the Fermi level in cubic ((111)CD-I and (111)CD-II) and hexagonal ((2¯110)HD)-II) superlattices resulted in magnetic moments of 3.99μB, 3.99μB, and 1.99μB per unit cell, respectively. Various configurations significantly impacted their electronic properties, resulting in spin-polarized and non-spin-polarized systems with flat bands near the Fermi level, exhibiting a semiconducting nature. The averaged spin moments per carbon atom were 0.16μB, 0.14μB, and 0.08μB, localized at the sp2/sp3 interfaces of the nanodiamond sites. Analysis of the electronic states, band structure, charge carrier effective masses, and spin density distribution suggests NDI-c2G shares similar electronic nature to strongly correlated twisted bilayer graphenes at small magic angles.

EXPERIMENTAL INVESTIGATION OF AMINE-BASED GRAPHENE NANOSUSPENSION FOR CO2 ABSORPTION

Absorption is the most widely used carbon dioxide (CO2) removal technology. The CO2 absorption performance of monoethanolamine (MEA), the most commonly used CO2 absorbent, can be improved by suspending nanoparticles. This work examined the performance of graphene nanoplatelets (GNPs) as additives to enhance CO2 absorption in MEA. The GNPs were characterized by HRTEM, FTIR, and XRD. The study examined the influence of GNP concentrations on CO2 absorption at room temperature. The images from HRTEM confirmed that the implemented graphene consists of several layers of graphene sheets. Increasing the loading of particles increased the solubility of CO2 until the optimum concentration was reached. From this work, it is evident that incorporating GNPs into MEA enhances the CO2 absorption performance of MEA. Thus, the addition of nanoparticles to the absorbent can enhance its CO2 absorptivity.

Highly Efficient Laser Bidirectional Graphene Printing: Integration of Synthesis, Transfer and Patterning.

Graphene has tremendous potential in future electronics due to its superior force, electrical, and thermal properties. However, the development of graphene devices is limited by its complex, high-cost, and low-efficiency preparation process. This study proposes a novel laser bidirectional graphene printing (LBGP) process for the large-scale preparation of patterned graphene films. In LBGP, a sandwich sample composed of a thermoplastic elastomer (TPE) substrate, carbon precursor powder, and a glass cover is irradiated by a nanosecond pulsed laser. The laser photothermal effect converts the carbon precursor into graphene, with partial graphene sheets deposited directly on the TPE substrate and the remaining transferred to the glass cover via a laser-induced plasma plume. This method simultaneously prepares two face-to-face graphene films in a single laser irradiation, integrating synthesis, transfer, and patterning. The resulting graphene patterns demonstrate good performance in flexible pressure sensing and Joule heating, showcasing high sensitivity (7.7kPa-1), fast response (37ms), and good cycling stability (2000 cycles) for sensors, and high heating rate (1°Cs-1) and long-term stability (3000s) for heaters. It is believed that the simple, low-cost, and efficient LBGP process can promote the development of graphene electronics and laser manufacturing processes.