Graphene - Science topic

Since the S-Se combination as electrodes in batteries, hybrid composites for lithium sulfur-selenium (LiS-Se) batteries have attracted substantial attention. In this work, we have synthesized MoSSe-multilayered graphene (MLG) (with two different ratios of S: Se precursor) by solvothermal method followed by the calcination of trapped organic solvent...

Increasing the efficiency of perovskite solar cells due to the problem of instability is one of the challenging problems in this field. The use of different chemical materials as well as organic materials or the use of polymer compounds is one of the alternative options in the different layers of perovskite solar cells. Due to the lack of stability...

Nitrogen (N) doped graphene materials have been synthesized using the sole precursor adenine on the Ir(111) and Ru(0001) surfaces. X-ray photoelectron spectroscopy and scanning tunneling microscopy (STM) have been used to characterize the obtained N-doped graphene materials. Several graphitic and pyridinic N dopants have been identified on the atom...

In this study, we present a chiral metasurface structure based on graphene-Au elliptical hole arrays. Circular dichroism of up to 0.91 is achieved by varying the rotation angle of the elliptical hole. Circular dichroism (CD) typically expresses the chiral response. The structure has excellent absorption of right circularly polarized light while ref...

Citation: Andonegi, M.; Correia, D.M.; Pereira, N.; Costa, C.M.; Lanceros-Mendez, S.; de la Caba, K.; Guerrero, P. Sustainable Collagen Composites with Graphene Oxide for Bending Resistive Sensing. Polymers 2023, 15, 3855. https://doi. Abstract: This work reports on the development of collagen films with graphene oxide nanoparticles (GO NPs), aimin...

Different cuprous oxide (Cu2O) particle forms, including the octahedron, truncated octahe-dron, cube, and star-like forms, are synthesized through chemical reduction under different reactionconditions. The correlation between the morphology and the catalytic activity of hydrogen evolutionreactions (HERs) is investigated. It is discovered that the C...

The H-polarized waves scattering and absorption by a metasurface, which consists of a multilayer grating of finite number of graphene strips inside a grounded dielectric slab is considered. The problem is considered in the domain of Fourier transform (spectral domain). The solution is obtained in two steps. At first, the scattering operators of a s...

We investigate the radiation of the THz natural waves of the dielectric waveguide with graphene plane scattered by finite number of graphene strips. Our mathematically accurate analysis uses the singular integral equations method. The discretization scheme employs the Nystrom-type algorithm. The complex-valued propagation constants of the natural w...

2D layered semiconductor materials hold the potential to address the crucial technical challenges of poor signal uniformity and low repeatability of traditional metal plasmonic nanostructures in sensing, which hinder quantitative detection and analysis in molecular detection. However, the ultra-low light absorption efficiency and electronic state d...

In this paper, graphene based SRR loaded on a two-port antenna with high isolation and polarization diversity is used for THz applications. The size of the two-port antenna is compact and two microstrip-fed radiators are placed orthogonally to achieve the polarization diversity. The defective ground and stub are implemented to achieve impedance mat...

We investigate electronic states in a two-dimensional network consisting of interacting quantum wires, a model adopted for twisted bilayer systems. We construct general operators which describe various scattering processes in the system. In a twisted bilayer structure, the moiré periodicity allows for generalized umklapp scatterings, leading to a c...

Within this study, we explored the augmented security measures for the electronics of unmanned aerial vehicles (UAVs) within an RF environment. UAVs are commonly utilised across various sectors, and their use as auxiliary platforms for cellular networks, as parallel networks working in tandem with ground-based base stations, holds considerable prom...

Microwave absorbers have many applications in medical, industrial, and military devices. Polymeric composites including carbon-based filler can be used as lightweight absorbers with high electromagnetic (EM) wave absorption performance. Hence, multilayer microwave absorbers were designed using titanium dioxide (TiO2)/reduced graphene oxide (RGO)/ep...

The requirements for broadband photodetection are becoming exceedingly demanding in hyperspectral imaging. While intrinsic photoconductor arrays based on mercury cadmium telluride represent the most sensitive and suitable technology, their optical spectrum imposes a narrow spectral range with a sharp absorption edge that cuts their operation to <25...

Organic donor‐acceptor semiconductors exhibit great potential in photothermal conversion. However, it is still challenging to achieve pure organic materials with broad absorption comparable with inorganic materials such as graphene. Herein, two D‐A‐D type DPA‐BT‐O 4 and NDI‐TPA‐O 4 and three D‐A‐π‐A‐D type Th‐O 4 , Th 2 ‐O 4 , and IDT‐O 4 were read...

Vanadium dioxide (VO2) has attracted extensive attention due to the specific metal-insulator phase transition as well as the wide device applications. The practical performance of VO2-based device strongly depends on the quality of VO2, since the higher quality of VO2 film always shows much more pronounced phase transition behavior. Thus, the prepa...

The viscosity properties of GNP-alumina hybrid nanofluids are of significant importance in various engineering applications. This study compares the predictive performance of response surface methodology (RSM), artificial neural network (ANN), and adaptive neuro-fuzzy inference system (ANFIS) for the viscosity (µrel) and relative viscosity (µrel) o...

In this study, a rapid, selective and sensitive method was developed for the determination of valganciclovir (VLG). The electrochemical oxidation of VLG was studied at the designed sensor based on magnetic nanoparticles (Fe 3 O 4), graphene and Nafion via cyclic and square wave voltammetry in a wide pH range. The oxidation signal of the drug was si...

In this study, we conducted a numerical investigation of the turbulent mixed convection of a hybrid nanofluid (HNF) in a flask equipped with an agitator, which is commonly used in organic chemistry synthesis. The bottom wall and the middle section of the flask were maintained at a constant high temperature Th, while the upper, left, and right walls...

This article investigates the influence of the addition method of graphene to activated carbon (AC) on the electrochemical performance of the fabricated electric double‐layer capacitors (EDLCs). To do so, the same graphene material is introduced to the other electrode slurry materials either in the form of a powder (GP) or a suspension (GL). It is...

Supercapacitors, which are among the energy storage systems, have a high power density, a fast charge–discharge time, a long cycle life, and a low energy capacity. In this study, it is aimed to produce electrically conducting carbon nanofiber/reduced graphene oxide (CNF/rGO) composites as electrodes in supercapacitors. Polyacrylonitrile nanofibers...

This study aims to explicate the diverse roles of high entropy alloys within nuclear environments. The study extensively investigates the impact of B4C on the structural, physical, mechanical, and nuclear shielding properties of synthesized high-entropy alloys (HEAs) comprising FeNiCoCrW, GNP, and B4C. The aim is to explore the monotonic effects of...

The arrangement of a water thermal accumulator (WTA) containing phase change materials (PCM) is presented and analyzed. The hot or cool water is used as a working body. The accumulator contains two concentric cylindrical tubes. The inner tube is used for hot or cool water flowing, while the volume between the inner and outer tubes is filled with PC...

Composites based on Al-Fe alloys and reinforced with three-layer graphene sheets were synthesized “in situ” under a layer of molten salts. Composites containing 0.12 wt.% graphene were subjected to severe plastic deformation via high-pressure torsion. SEM and TEM were used to study the morphological and size characteristics of the composite structu...

Topological indices are graph-theoretically based characteristics that allow for the characterization of a molecular structure's underlying connectivity. Degree-based topological indices have been the subject of substantial research and have been connected to numerous chemical characteristics. Gaining relevance is the study of graph entropy indices...

The graphene field-effect transistor (GFET) has the severe drawback of the device turn off owing to the zero band gap of graphene that results in a limited on/off current ratio at room temperature. In this report, we propose a hybrid channel of few graphene oxide (GO) implanted with undoped p-type anatase TiO2 nanoparticles (~16 nm) to achieve a de...

Dynamically controlling friction in micro- and nanoscale devices is possible using applied electrical bias between contacting surfaces, but this can also induce unwanted reactions which can affect device performance. External electric fields provide a way around this limitation by removing the need to apply bias directly between the contacting surf...

We study the simplest Lamé magnetic superlattice in graphene, finding its allowed and forbidden energy bands and band-edge states explicitly. Then, we design quasiperiodic magnetic superlattices supporting bound states using Darboux transformations. This technique enables us to add any finite number of bound states, which we exemplify with the most...

Fe–N–C material, known for its high efficiency, cost-effectiveness, and environmental friendliness, is a promising electrocatalyst in the field of the oxygen reduction reaction (ORR). However, the influence of defects and coordination structures on the catalytic performance of Fe–N–C has not been completely elucidated. In our present investigation,...

This study presented experimental research on the alternating current (AC) impedance spectrum of graphene-enhanced cement matrix composites with dosage amounts of 0.1%, 0.2%, 0.4%, 0.8%, 1.6%, and 3.2%, respectively. The electrical properties were compared and analyzed with the Nyquist diagram, Bode diagram, and phase angle diagram. The microscopic...

In this work, for the first time, the effects of Boron (B) and Carbon (C) substitutional doping/co-doping on the quantum capacitance of monolayer Phosphorene (Ph) have been extensively investigated for electrode design of electrical double-layer (EDL) supercapacitor. In this context, the effects of different doping concentrations on local charge di...

This article presents the nonlinear investigation of the thermal and mechanical buckling of orthotropic annular/circular single-layer/bilayer nanoplate with the Pasternak and Winkler elastic foundations based on the nonlocal strain gradient theory. The stability equations of the graphene plate are derived using higher-order shear deformation theory...

We attempted to grow (10–13) semi-polar GaN on graphene to confirm the possibility of a remote epitaxy of semi-polar GaN. Single crystalline (10–13) GaN was obtained on an optimized template using optimized growth conditions. However, (10–13), (0002), and other GaN orientations were found under the same growth conditions on a graphene-coated templa...

The employment of nanoparticle additives in engine oil provides an effective technique for improvement in engine performance and emission. In this study, graphene, graphene–MWCNT, and graphene–SiO2 hybrid nanoparticles have been dispersed in engine oil (n-decane) to measure the effects of microscopic characteristics of interfacial layer between the...

We model the influence of an in-plane magnetic field on the orbital motion of electrons in rhombohedral graphene multilayers. For zero field, the low-energy band structure includes a pair of flat bands near zero energy, which are localized on the surface layers of a finite thin film. For finite field, we find that the zero-energy bands persist and...

The valley pseudospin properties of electrons in two–dimensional hexagonal materials result in lots of fascinating physical phenomena, which opens up the new field of valleytronics. The valley-contrasting physics aims at distinguishing the valley degree of freedom based on valley–dependent effects. Here, we theoretically demonstrate that both of th...

A graphene-coated uniaxial chiral cylindrical waveguide is proposed. Correspondingly, the characteristic equation is derived using appropriate boundary conditions. The effect of chemical potential and chiral parameters is analyzed on propagation modes and energy flux. The characteristics of the hybrid propagation mode in the graphene-coated uniaxia...

The novel proposal of Wang’s triboelectric nanogenerator (TENG) has inspired extensive efforts to explore energy harvesting devices from the living environment for the upcoming low-carbon society. The inevitable friction and wear problems of the tribolayer materials become one of the biggest obstacles for attaining high-performance TENGs. To achiev...

In this work, we will study the transmission probability of Dirac fermions through a double laser barrier. As part of the Floquet approximation, we will determine the spinors in the five regions. Due to the continuity of the wave function at the barrier edges, we find eight equations, each with infinity modes. To simplify, we use the matrix formali...

The effect of oxidized graphene on the quality parameters of diesel fuel for transport was examined in this ‎study. The research covered base diesel fuel and diesel fuel containing an additive package. ‎Both tested fuels contained no biocomponent. The method of preparing a stable mixture of ‎graphene material in each tested diesel fuels was develop...

The present work emphasizes the fabrication of pioneering electrodes (α-Ag2S, silver sulfide) for high-performance supercapacitors via simple chemistry approach. α-Ag2S nanomaterials prepared in the present study exhibited a unique morphology with highlighting electrochemical features. When tested as an electrode material in three-cell configuratio...

Polymer electret synaptic transistor is a promising three‐terminal artificial synaptic device. In this work, the electrical characteristics of the composite insulator and transistor are enhanced by modulating the concentration of the 2D nanofiller graphene oxide (GO) and the stacked film structure based on a polyvinyl alcohol (PVA) matrix. The GO‐P...

Hydrogen isotope separation is of prime significance in various scientific and industrial applications. Nevertheless, the existing technologies are often expensive and energy demanding. Two-dimensional carbon materials are regarded as promising candidates for cost-effective separation of different hydrogen isotopes. Herein, based on theoretical cal...

The effects due to edges on flat bands in twisted bilayer graphene are explained. In particular, the strong localization in AA sites explains the robust charater of the flat band. However, edges that break the quantum well pottential at AA sites produce effects that are well described by a simple model. This work is in agreement with experiments on...

Twisted bilayer graphene (TBG) is known for exhibiting highly correlated phases at magic angles due to the emergence of flat bands that enhance electron-electron interactions. The connection between magic angles and the Quantum Hall effect remains a topic of ongoing research. In the TBG chiral model, electronic wave function properties depend on a...

Development of an efficient photothermal materials with multifunctional capabilities is considered as an effective approach for utilizing abundant free solar energy and exploring new concepts for prospective sustainable energy and...

The peridynamic (PD) theory is a nonlocal reformulation of mechanics with various advantages over common approaches, mainly local continuum mechanics and molecular dynamics (MD). PD theory can capture phenomena at different dimensions, including nanoscale. However, limited studies have been performed by this theory in nanoscale, which have generall...

The thermal conductivity of graphene is in the range of 3000–5000 W m⁻¹ K⁻¹, showing great potential in high thermal conductivity devices. However, the thermal conductivity of graphene-reinforced polymer is typically lower than 10 W m⁻¹ K⁻¹, which is far from theoretical expectations. To understand the mechanisms of heat transfer in graphene-reinfo...

Understanding the characteristics of intrinsic defects in crystals is of great interest in many fields, from fundamental physics to applied materials science. Combined investigations of scanning tunneling microscopy/spectroscopy (STM/S) and...

In deep unconventional oil and gas development, the problem faced is that PDC bits are eroded by solid-liquid high-speed fluids, resulting in damage. It has led to serious damage to the stability of the drill bit, a decrease in the service life of the drill bit, and an increase in the difficulty in efficient drilling. The essence is that the surfac...

Differentiating dry eye disease (DED) from allergic or viral conjunctivitis rapidly and accurately is important to ensure prompt diagnosis and treatment. Tear lactoferrin (LF), a multi-functional glycoprotein found in tears, decreases significantly in patients with DED, and has been considered as a DED diagnostic biomarker. Measuring tear LF level,...

Surface plasmon resonance (SPR) sensors have emerged as powerful tools for detecting and analyzing changes in the refractive index (RI) of surrounding media. In this paper, we present a highly sensitive SPR sensor implemented on a graphene metasurface for the detection of low RI variations. We have incorporated glass structure as the substrate in t...

Efficient graphene production is critical for commercial applications. Liquid-phase exfoliation, one of the most promising methods for mass production of graphene, is limited by small size and low yield. By optimizing the fluid forces, we have achieved the size-controlled production of high-quality graphene. The bending and cleavage caused by the c...

This study investigates and compares the experimental heat transfer performance and simulation via computational fluid dynamics (CFD) of graphene nanoplatelets (GNP) and water nanofluids GNP/water in the double-tube-type heat exchanger (DTHE). Tests were conducted with water/water and GNP/water fluids, with the nanofluid for the hot-fluid circuit a...

Thermoelectric effects are highly sensitive to the asymmetry in the density of states around the Fermi energy and can be exploited as probes of the electronic structure. We experimentally study thermopower in high-quality monolayer graphene, within heterostructures consisting of complete hBN encapsulation and 1D edge contacts, where the graphene an...

An electrochemical determination of Pb2+ by cyclic voltammetry, differential pulse voltammetry, and differential pulse anodic stripping voltammetry in various waters using a glassy carbon electrode modified with graphene/Nafion mixture has been developed. A series of optimum conditions such as graphene concentration, modifying amount, Nafion concen...

Binary transition metal sulfides have garnered widespread concentration result from their superior electrical conductivity and outstanding capacitance. However, their poor cycling stability hinders their applications in energy storage devices. The objective of this study is to devise and prepare graphene and NiCo2S4 composite (NiCo2S4@graphene) usi...

Understanding the performance of graphene devices in contact with highly concentrated aqueous electrolytes is key to integrating graphene into next-generation devices operating in sea water environments, biosensors, and high-density energy production/storage units. Despite significant efforts toward interpreting the structure of the electrochemical...

Graphene aerogels (GAs) possess a remarkable capability to absorb electromagnetic waves (EMWs) due to their favorable dielectric characteristics and unique porous structure. Nevertheless, the introduction of nitrogen atoms into graphene aerogels can result in improved impedance matching. In recent years, nitrogen-doped graphene aerogels (NGAs) have...

Our study employs the Timoshenko beam theory to thoroughly investigate the propagation of waves in auxetic metamaterial beams enabled by functionally graded graphene origami. This exploration is conducted while the Winkler–Pasternak foundation supports the beams. In addition, many distinct graphene origami (GOri) distribution patterns have been exp...