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Journal articles on the topic 'Graphene based 2-dimensional systems'
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1
Dolina, Ekaterina S., Pavel A. Kulyamin, Anastasiya A. Grekova, Alexey I. Kochaev, Mikhail M. Maslov, and Konstantin P. Katin. "Thermal Stability and Vibrational Properties of the 6,6,12-Graphyne-Based Isolated Molecules and Two-Dimensional Crystal." Materials 16, no. 5 (February 27, 2023): 1964. http://dx.doi.org/10.3390/ma16051964.
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We report the geometry, kinetic energy, and some optical properties of the 6,6,12-graphyne-based systems. We obtained the values of their binding energies and structural characteristics such as bond lengths and valence angles. Moreover, using nonorthogonal tight-binding molecular dynamics, we carried out a comparative analysis of the thermal stability of 6,6,12-graphyne-based isolated fragments (oligomer) and two-dimensional crystals constructed on its basis in a wide temperature range from 2500 to 4000 K. We found the temperature dependence of the lifetime for the finite graphyne-based oligomer as well as for the 6,6,12-graphyne crystal using a numerical experiment. From these temperature dependencies, we obtained the activation energies and frequency factors in the Arrhenius equation that determine the thermal stability of the considered systems. The calculated activation energies are fairly high: 1.64 eV for the 6,6,12-graphyne-based oligomer and 2.79 eV for the crystal. It was confirmed that the thermal stability of the 6,6,12-graphyne crystal concedes only to traditional graphene. At the same time, it is more stable than graphene derivatives such as graphane and graphone. In addition, we present data on the Raman and IR spectra of the 6,6,12-graphyne, which will help distinguish it from the other carbon low-dimensional allotropes in the experiment.
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KAN, ERJUN, ZHENYU LI, and JINLONG YANG. "MAGNETISM IN GRAPHENE SYSTEMS." Nano 03, no. 06 (December 2008): 433–42. http://dx.doi.org/10.1142/s1793292008001350.
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Graphene has attracted great interest in materials science, owing to its novel electronic structures. Recently, magnetism discovered in graphene-based systems has opened up the possibility of their spintronics application. This paper provides a comprehensive review of the magnetic behaviors and electronic structures of graphene systems, including two-dimensional graphene, one-dimensional graphene nanoribbons, and zero-dimensional graphene nanoclusters. Theoretical research suggests that such metal-free magnetism mainly comes from the localized states or edges states. By applying an external electric field, or by chemical modification, we can turn the zigzag nanoribbon systems into half metal, thus obtaining a perfect spin filter.
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Marchenko, D., D. V. Evtushinsky, E. Golias, A. Varykhalov, Th Seyller, and O. Rader. "Extremely flat band in bilayer graphene." Science Advances 4, no. 11 (November 2018): eaau0059. http://dx.doi.org/10.1126/sciadv.aau0059.
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We propose a novel mechanism of flat band formation based on the relative biasing of only one sublattice against other sublattices in a honeycomb lattice bilayer. The mechanism allows modification of the band dispersion from parabolic to “Mexican hat”–like through the formation of a flattened band. The mechanism is well applicable for bilayer graphene—both doped and undoped. By angle-resolved photoemission from bilayer graphene on SiC, we demonstrate the possibility of realizing this extremely flattened band (< 2-meV dispersion), which extends two-dimensionally in a k-space area around the K¯ point and results in a disk-like constant energy cut. We argue that our two-dimensional flat band model and the experimental results have the potential to contribute to achieving superconductivity of graphene- or graphite-based systems at elevated temperatures.
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Knoll, T., G. Jenke, A. Brenner, H. Schuck, A. Schultz, R. Warmers, A. Zumbülte, et al. "Zweifarben-Druckanlage für die Sensorherstellung/Two-colour printing machine for sensor production - Rotary printing of foil-based graphene sensors." wt Werkstattstechnik online 107, no. 11-12 (2017): 827–33. http://dx.doi.org/10.37544/1436-4980-2017-11-12-51.
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Der Fachartikel stellt eine kompakte Zweifarben-Druckanlage für die Fertigung folienbasierter Sensoren aus Graphen vor. Mithilfe einer Graphentinte sowie eines rotativen Tiefdruckverfahrens lassen sich zweidimensionale Elektrodenstrukturen beliebiger Geometrie in hohen Stückzahlen fertigen. Beschrieben werden die Druckanlage, die Herstellung der Tiefdruckzylinder und der graphenbasierten Tinte sowie die bisher beim Drucken von Elektroden für zellbasierte Sensoren erzielten Ergebnisse. The article presents a compact two-colour printing system for the production of foil-based sensors made of graphene. Graphene is a suitable material for electrodes of cell-based sensors. If graphene is used as a printable ink, two-dimensional electrode structures of any geometry can be produced. The article describes the printing system, the production of the gravure cylinders and the graphene-based ink as well as the results of printing experiments achieved so far.
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Barlas, Yafis, Kun Yang, and A. H. MacDonald. "Quantum Hall effects in graphene-based two-dimensional electron systems." Nanotechnology 23, no. 5 (January 11, 2012): 052001. http://dx.doi.org/10.1088/0957-4484/23/5/052001.
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Chen, Yiwen, Habibullah, Guanghui Xia, Chaonan Jin, Yao Wang, Yigang Yan, Yungui Chen, Xiufang Gong, Yuqiu Lai, and Chaoling Wu. "Palladium-Phosphide-Modified Three-Dimensional Phospho-Doped Graphene Materials for Hydrogen Storage." Materials 16, no. 12 (June 7, 2023): 4219. http://dx.doi.org/10.3390/ma16124219.
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The development of efficient hydrogen storage materials is crucial for advancing hydrogen-based energy systems. In this study, we prepared a highly innovative palladium-phosphide-modified P-doped graphene hydrogen storage material with a three-dimensional configuration (3D Pd3P0.95/P-rGO) using a hydrothermal method followed by calcination. This 3D network hindering the stacking of graphene sheets provided channels for hydrogen diffusion to improve the hydrogen adsorption kinetics. Importantly, the construction of the three-dimensional palladium-phosphide-modified P-doped graphene hydrogen storage material improved the hydrogen absorption kinetics and mass transfer process. Furthermore, while acknowledging the limitations of primitive graphene as a medium in hydrogen storage, this study addressed the need for improved graphene-based materials and highlighted the significance of our research in exploring three-dimensional configurations. The hydrogen absorption rate of the material increased obviously in the first 2 h compared with two-dimensional sheets of Pd3P/P-rGO. Meanwhile, the corresponding 3D Pd3P0.95/P-rGO-500 sample, which was calcinated at 500 °C, achieved the optimal hydrogen storage capacity of 3.79 wt% at 298 K/4 MPa. According to molecular dynamics, the structure was thermodynamically stable, and the calculated adsorption energy of a single H2 molecule was −0.59 eV/H2, which was in the ideal range of hydrogen ad/desorption. These findings pave the way for the development of efficient hydrogen storage systems and advance the progress of hydrogen-based energy technologies.
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Wang, Xiunan, Yi Liu, Jingcheng Xu, Shengjuan Li, Fada Zhang, Qian Ye, Xiao Zhai, and Xinluo Zhao. "Molecular Dynamics Study of Stability and Diffusion of Graphene-Based Drug Delivery Systems." Journal of Nanomaterials 2015 (2015): 1–14. http://dx.doi.org/10.1155/2015/872079.
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Graphene, a two-dimensional nanomaterial with unique biomedical properties, has attracted great attention due to its potential applications in graphene-based drug delivery systems (DDS). In this work graphene sheets with various sizes and graphene oxide functionalized with polyethylene glycol (GO-PEG) are utilized as nanocarriers to load anticancer drug molecules including CE6, DOX, MTX, and SN38. We carried out molecular dynamics calculations to explore the energetic stabilities and diffusion behaviors of the complex systems with focuses on the effects of the sizes and functionalization of graphene sheets as well as the number and types of drug molecules. Our study shows that the binding of graphene-drug complex is favorable when the drug molecules and finite graphene sheets become comparable in sizes. The boundaries of finite sized graphene sheets restrict the movement of drug molecules. The double-side loading often slows down the diffusion of drug molecules compared with the single-side loading. The drug molecules bind more strongly with GO-PEG than with pristine graphene sheets, demonstrating the advantages of functionalization in improving the stability and biocompatibility of graphene-based DDS.
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Jana, Susmita, Arka Bandyopadhyay, Sujoy Datta, Debaprem Bhattacharya, and Debnarayan Jana. "Emerging properties of carbon based 2D material beyond graphene." Journal of Physics: Condensed Matter 34, no. 5 (November 10, 2021): 053001. http://dx.doi.org/10.1088/1361-648x/ac3075.
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Abstract Graphene turns out to be the pioneering material for setting up boulevard to a new zoo of recently proposed carbon based novel two dimensional (2D) analogues. It is evident that their electronic, optical and other related properties are utterly different from that of graphene because of the distinct intriguing morphology. For instance, the revolutionary emergence of Dirac cones in graphene is particularly hard to find in most of the other 2D materials. As a consequence the crystal symmetries indeed act as a major role for predicting electronic band structure. Since tight binding calculations have become an indispensable tool in electronic band structure calculation, we indicate the implication of such method in graphene’s allotropes beyond hexagonal symmetry. It is to be noted that some of these graphene allotropes successfully overcome the inherent drawback of the zero band gap nature of graphene. As a result, these 2D nanomaterials exhibit great potential in a broad spectrum of applications, viz nanoelectronics, nanooptics, gas sensors, gas storages, catalysis, and other specific applications. The miniaturization of high performance graphene allotrope based gas sensors to microscopic or even nanosized range has also been critically discussed. In addition, various optical properties like the dielectric functions, optical conductivity, electron energy loss spectra reveal that these systems can be used in opto-electronic devices. Nonetheless, the honeycomb lattice of graphene is not superconducting. However, it is proposed that the tetragonal form of graphene can be intruded to form new hybrid 2D materials to achieve novel superconducting device at attainable conditions. These dynamic experimental prospects demand further functionalization of these systems to enhance the efficiency and the field of multifunctionality. This topical review aims to highlight the latest advances in carbon based 2D materials beyond graphene from the basic theoretical as well as future application perspectives.
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Koppens, F. H. L., T. Mueller, Ph Avouris, A. C. Ferrari, M. S. Vitiello, and M. Polini. "Photodetectors based on graphene, other two-dimensional materials and hybrid systems." Nature Nanotechnology 9, no. 10 (October 2014): 780–93. http://dx.doi.org/10.1038/nnano.2014.215.
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Si, Wei, Chang Chen, Gensheng Wu, Qianyi Sun, Meng Yu, Yu Qiao, and Jingjie Sha. "High Efficient Seawater Desalination Based on Parallel Nanopore Systems." Nano 16, no. 07 (June 21, 2021): 2150077. http://dx.doi.org/10.1142/s1793292021500776.
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Graphene is one of the most attractive two-dimensional materials that can be used for efficient desalination due to its ideal physical properties and high performance in ion selectivity and salt rejection. Here, in this paper, molecular dynamics simulations were applied to investigate the possibility of using a parallel nanopore system to pump ions so that the ions of both cation and anion species in the middle compartment could be evacuated at an extremely rapid rate. By building hexagonal parallel single-layer graphene films with spacing of 3.0 nm and changing the pore numbers and surface charge densities of the nanopores, the efficiency of desalination could be well controlled. It is found that the ion concentration decreases exponentially with time. The more the number of nanopore is, the stronger the surface charge density of nanopore is, the evacuation of ions in the middle compartment is more obvious, offering a new means for controlling the desalination efficiency. The simulations performed here provide theoretical insights for designing and fabricating high efficient and less energy consumption graphene desalination devices in the future.
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Kaptagai, G. A., B. M. Satanova, F. U. Abuova, N. O. Koilyk, A. U. Abuova, S. A. Nurkenov, and A. P. Zharkymbekova. "OPTICAL PROPERTIES OF LOW-DIMENSIONAL SYSTEMS: METHODS OF THEORETICAL STUDY OF 2D MATERIALS." NNC RK Bulletin, no. 4 (December 31, 2022): 35–40. http://dx.doi.org/10.52676/1729-7885-2022-4-35-40.
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Heterostructures based on graphene and two-dimensional films of nanostructured, ferromagnetic, transition metal oxides are promising for the development of new multifunctional materials for memory cells, quantum computer elements, Li-battery anodes, (photo) catalysts, supercapacitors, transistors, sensor materials, solar panels, fuel cells, electrochromic devices. A large volume of publications devoted to graphene and heterostructures based on it is and mainly their synthesis processes of hybrid structures. The methods of theoretical investigation of the optical properties of two-dimensional film materials, despite their diversity, require improvement. Consequently, the article presents methods of theoretical investigation of the optical properties of two-dimensional hybrid film structures in combination with ab-initio method.
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Meng, Yancheng, Baowen Li, Luxian Li, and Jianqiang Zhang. "Buckling Behavior of Few-Layer Graphene on Soft Substrate." Coatings 12, no. 12 (December 17, 2022): 1983. http://dx.doi.org/10.3390/coatings12121983.
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The buckling behavior of graphene on soft films has been extensively studied. However, to avoid graphene fracture, most studies focus only on the primary buckling behavior induced by tiny compression. Here, the buckling behavior of monolayer, three-layer, and four-layer graphene on soft films is systematically studied in the experiment under large compression. The cross-sections of buckling patterns in these few-layer graphenes are provided, which depend on focused ion beam (FIB) technology. More significantly, the moduli of few-layer graphene are calculated based on the buckling behavior. We demonstrate that the modulus, 1.12621 TPa, is independent of the number of graphene layers if the number is less than four. Our investigations are crucial for the application of two-dimensional (2D) materials into flexible hybrid electronics, bionics, and various other stiff/soft bilayer systems.
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Jorio, Ado. "Raman Spectroscopy in Graphene-Based Systems: Prototypes for Nanoscience and Nanometrology." ISRN Nanotechnology 2012 (December 6, 2012): 1–16. http://dx.doi.org/10.5402/2012/234216.
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Raman spectroscopy is a powerful tool to characterize the different types of sp2 carbon nanostructures, including two-dimensional graphene, one-dimensional nanotubes, and the effect of disorder in their structures. This work discusses why sp2 nanocarbons can be considered as prototype materials for the development of nanoscience and nanometrology. The sp2 nanocarbon structures are quickly introduced, followed by a discussion on how this field evolved in the past decades. In sequence, their rather rich Raman spectra composed of many peaks induced by single- and multiple-resonance effects are introduced. The properties of the main Raman peaks are then described, including their dependence on both materials structure and external factors, like temperature, pressure, doping, and environmental effects. Recent applications that are pushing the technique limits, such as multitechnique approach and in situ nanomanipulation, are highlighted, ending with some challenges for new developments in this field.
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Fang, Haiqiu, Dongfang Yang, Zizhen Su, Xinwei Sun, Jiahui Ren, Liwei Li, and Kai Wang. "Preparation and Application of Graphene and Derived Carbon Materials in Supercapacitors: A Review." Coatings 12, no. 9 (September 8, 2022): 1312. http://dx.doi.org/10.3390/coatings12091312.
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Graphene has recently attracted a wide range of research interests due to its rigorous two-dimensional structure and extraordinary electrical, thermal and mechanical properties. As a conductive agent, an activated carbon supercapacitor can obtain better performance. This paper summarizes the latest research progress, mainly from two aspects: (1) the preparation of an activated carbon base for a supercapacitor based on waste sugar solution and the relationship between pore structure and activation parameters, and (2) the application of the two-dimensional materials graphene and its composite materials in electric double-layer capacitors, graphene–polymer composite tantalum capacitors, graphene–transition metal oxide composite tantalum capacitors, and asymmetric super capacitors. The studies found that graphene and its composite materials have obvious advantages in improving the cycle efficiency, conversion rate, and energy density of supercapacitors, the overall energy efficiency of mechanical systems, and the chemical properties of nanoelectronics. Therefore, it is urgent to summarize these works in order to promote the next development. Graphene is expected to be effectively and environmentally quantified in the near future, and its application in supercapacitors will be further expanded and matured.
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Monne, Mahmuda Akter, Peter Mack Grubb, Harold Stern, Harish Subbaraman, Ray T. Chen, and Maggie Yihong Chen. "Inkjet-Printed Graphene-Based 1 × 2 Phased Array Antenna." Micromachines 11, no. 9 (September 18, 2020): 863. http://dx.doi.org/10.3390/mi11090863.
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Low-cost and conformal phased array antennas (PAAs) on flexible substrates are of particular interest in many applications. The major deterrents to developing flexible PAA systems are the difficulty in integrating antenna and electronics circuits on the flexible surface, as well as the bendability and oxidation rate of radiating elements and electronics circuits. In this research, graphene ink was developed from graphene flakes and used to inkjet print the radiating element and the active channel of field effect transistors (FETs). Bending and oxidation tests were carried out to validate the application of printed flexible graphene thin films in flexible electronics. An inkjet-printed graphene-based 1 × 2 element phased array antenna was designed and fabricated. Graphene-based field effect transistors were used as switches in the true-time delay line of the phased array antenna. The graphene phased array antenna was 100% inkjet printed on top of a 5 mil flexible Kapton® substrate, at room temperature. Four possible azimuth steering angles were designed for −26.7°, 0°, 13°, and 42.4°. Measured far-field patterns show good agreement with simulation results.
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Li, Jinhui, Guoping Zhang, Rong Sun, and C. P. Wong. "Three-Dimensional Graphene-Based Composite for Elastic Strain Sensor Applications." MRS Advances 1, no. 34 (2016): 2415–20. http://dx.doi.org/10.1557/adv.2016.508.
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ABSTRACTFlexible electronics has emerged as a very promising field, in particular,wearable, bendable, and stretchable strain sensors with high sensitivity which could be used for human motion detection, sports performance monitoring, etc. In this paper, a highly stretchable and sensitive strain sensor composed of reduced graphene oxide foam and elastomer composite is fabricated by assembly and followed by a polymer immersing process. The strain sensor has demonstrated high stretchability and sensitivity. Furthermore, the device was employed for gauging muscle-induced strain which results in high sensitivity and reproducibility. The developed strain sensors showed great application potential in fields of biomechanical systems.
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Zhou, Fanglei, Mahdi Fathizadeh, and Miao Yu. "Single- to Few-Layered, Graphene-Based Separation Membranes." Annual Review of Chemical and Biomolecular Engineering 9, no. 1 (June 7, 2018): 17–39. http://dx.doi.org/10.1146/annurev-chembioeng-060817-084046.
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Two-dimensional, graphene-based materials have attracted great attention as a new membrane building block, primarily owing to their potential to make the thinnest possible membranes and thus provide the highest permeance for effective sieving, assuming comparable porosity to conventional membranes and uniform molecular-sized pores. However, a great challenge exists to fabricate large-area, single-layered graphene or graphene oxide (GO) membranes that have negligible undesired transport pathways, such as grain boundaries, tears, and cracks. Therefore, model systems, such as a single flake or nanochannels between graphene or GO flakes, have been studied via both simulations and experiments to explore the transport mechanisms and separation potential of graphene-based membranes. This article critically reviews literature related to single- to few-layered graphene and GO membranes, from material synthesis and characteristics, fundamental membrane structures, and transport mechanisms to potential separation applications. Knowledge gaps between science and engineering in this new field and future opportunities for practical separation applications are also discussed.
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Yi, Lingjun, and Changhong Li. "Simulation Study of In-Phase and Out-Phase Enhanced Absorption of Graphene Based on Parity–Time Symmetry One-Dimensional Photonic Crystal Structure." Crystals 11, no. 12 (December 4, 2021): 1513. http://dx.doi.org/10.3390/cryst11121513.
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In the field of modern optical communication systems and photoelectric detection, new components with complex functions and excellent performance are urgently needed. In this paper, a graphene-based parity–time (PT) symmetry structure is proposed, which is achieved by preparing the graphene layer on the top of a PT-symmetry photonic crystal. The transfer matrix method was used to calculate the absorptance of graphene, and a unique amplified absorption effect was found. Meanwhile, the peak value and wavelength position of the absorption can be modulated via the applied electric field. The results show that by adjusting the negative square-wave electric field from −3.5 × 10−5 to −13.5 × 10−5 V/nm (or the positive square-wave electric field from 2 × 10−5 to 11 × 10−5 V/nm), the proposed structure can achieve in-phase (or out-phase) enhanced absorption for the communication wavelength 1550 nm, with the absorption of graphene from 17 to 28 dB (or 30 to 15 dB) corresponding to the square-wave modulation electric field change. The modulable absorption properties of graphene in the structure have potential in optoelectronic devices and optical communication systems.
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Ksiksi, M. A., M. K. Azizi, H. Ajlani, and A. Gharsallah. "A Graphene based Frequency Reconfigurable Square Patch Antenna for Telecommunication Systems." Engineering, Technology & Applied Science Research 9, no. 5 (October 9, 2019): 4846–50. http://dx.doi.org/10.48084/etasr.3061.
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Current research on tunable patch antennas for wireless applications has mostly focused on the dimensional variations of patch elements, such as geometry and substrate materials, using different techniques to achieve the reconfiguration. The use of different mixing materials to ensure reconfiguration and improvement of antenna performance in microwave frequencies has not yet been studied thoroughly. In this article, we consider graphene as a patch material, due to its unique chemical, mechanical, electronic, thermal and optical features, which assist in providing a highly flexible and adaptive antenna. The proposed antenna is a square plate excited by a coaxial probe, operating at a 2.45GHz spectrum. Adding graphene to the antenna structure and tuning its chemical potential, a frequency reconfiguration from 2.36GHz to 1.26GHz is obtained. This antenna can be deployed in many communication systems. Results demonstrate the importance of this material in the development of nanoelectronics in the future.
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Wang, Yan, Lei Guo, Pengfei Qi, Xiaomin Liu, and Gang Wei. "Synthesis of Three-Dimensional Graphene-Based Hybrid Materials for Water Purification: A Review." Nanomaterials 9, no. 8 (August 3, 2019): 1123. http://dx.doi.org/10.3390/nano9081123.
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Graphene-based nanostructures and nanomaterials have been widely used for the applications in materials science, biomedicine, tissue engineering, sensors, energy, catalysis, and environmental science due to their unique physical, chemical, and electronic properties. Compared to two-dimensional (2D) graphene materials, three-dimensional (3D) graphene-based hybrid materials (GBHMs) exhibited higher surface area and special porous structure, making them excellent candidates for practical applications in water purification. In this work, we present recent advances in the synthesis and water remediation applications of 3D GBHMs. More details on the synthesis strategies of GBHMs, the water treatment techniques, and the adsorption/removal of various pollutants from water systems with GBHMs are demonstrated and discussed. It is expected that this work will attract wide interests on the structural design and facile synthesis of novel 3D GBHMs, and promote the advanced applications of 3D GBHMs in energy and environmental fields.
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Meenakshi, Sudheesh Shukla, Jagriti Narang, Vinod Kumar, Penny Govender, Avi Niv, Chaudhery Hussain, Rui Wang, Bindu Mangla, and Rajendran Babu. "Switchable Graphene-Based Bioelectronics Interfaces." Chemosensors 8, no. 2 (June 26, 2020): 45. http://dx.doi.org/10.3390/chemosensors8020045.
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Integration of materials acts as a bridge between the electronic and biological worlds, which has revolutionized the development of bioelectronic devices. This review highlights the rapidly emerging field of switchable interface and its bioelectronics applications. This review article highlights the role and importance of two-dimensional (2D) materials, especially graphene, in the field of bioelectronics. Because of the excellent electrical, optical, and mechanical properties graphene have promising application in the field of bioelectronics. The easy integration, biocompatibility, mechanical flexibility, and conformity add impact in its use for the fabrication of bioelectronic devices. In addition, the switchable behavior of this material adds an impact on the study of natural biochemical processes. In general, the behavior of the interfacial materials can be tuned with modest changes in the bioelectronics interface systems. It is also believed that switchable behavior of materials responds to a major change at the nanoscale level by regulating the behavior of the stimuli-responsive interface architecture.
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Navalón, Sergio, Wee-Jun Ong, and Xiaoguang Duan. "Sustainable Catalytic Processes Driven by Graphene-Based Materials." Processes 8, no. 6 (June 5, 2020): 672. http://dx.doi.org/10.3390/pr8060672.
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In the recent two decades, graphene-based materials have achieved great successes in catalytic processes towards sustainable production of chemicals, fuels and protection of the environment. In graphene, the carbon atoms are packed into a well-defined sp2-hybridized honeycomb lattice, and can be further constructed into other dimensional allotropes such as fullerene, carbon nanotubes, and aerogels. Graphene-based materials possess appealing optical, thermal, and electronic properties, and the graphitic structure is resistant to extreme conditions. Therefore, the green nature and robust framework make the graphene-based materials highly favourable for chemical reactions. More importantly, the open structure of graphene affords a platform to host a diversity of functional groups, dopants, and structural defects, which have been demonstrated to play crucial roles in catalytic processes. In this perspective, we introduced the potential active sites of graphene in green catalysis and showcased the marriage of metal-free carbon materials in chemical synthesis, catalytic oxidation, and environmental remediation. Future research directions are also highlighted in mechanistic investigation and applications of graphene-based materials in other promising catalytic systems.
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Ghanbarlou, Hosna, Nikoline Loklindt Pedersen, Morten Enggrob Simonsen, and Jens Muff. "Nitrogen-Doped Graphene Iron-Based Particle Electrode Outperforms Activated Carbon in Three-Dimensional Electrochemical Water Treatment Systems." Water 12, no. 11 (November 7, 2020): 3121. http://dx.doi.org/10.3390/w12113121.
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The synergy between electrochemical oxidation and adsorption on particle electrodes was investigated in three-dimensional (3D) systems for p-nitrosodimethylaniline (RNO) decolorization and pesticide removal. A comparison was made between granular activated carbon (GAC) and a novel synthesized nitrogen-doped graphene-based particle electrode (NCPE). Experiments on RNO decolorization show that the synergy parameter of the 3D-NCPE system was improved 3000 times compared to the studied 3D-GAC system. This was due to the specific nanostructure and composition of the NCPE material. Nitrogen-doped graphene triggered an oxygen reduction reaction, producing hydrogen peroxide that simultaneously catalyzed on iron sites of the NCPEs to hydroxyl radicals following the electro-Fenton (EF) process. Data showed that in the experimental setup used for the study, the applied cell voltage required for the optimal value of the synergy parameter could be lowered to 5V in the 3D-NCPEs process, which is significantly better than the 15–20 V needed for synergy to be found in the 3D-GAC process. Compared to previous studies with 3D-GAC, the removal of pesticides 2,6 dichlorobenzamide (BAM), 2-methyl-4-chlorophenoxyaceticacid (MCPA), and methylchlorophenoxypropionic acid (MCPP) was also enhanced in the 3D-NCPE system.
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Zhang, Yani, Lei Zhou, Dun Qiao, Mengyin Liu, Hongyan Yang, Cheng Meng, Ting Miao, Jia Xue, and Yiming Yao. "Progress on Optical Fiber Biochemical Sensors Based on Graphene." Micromachines 13, no. 3 (February 23, 2022): 348. http://dx.doi.org/10.3390/mi13030348.
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Graphene, a novel form of the hexagonal honeycomb two-dimensional carbon-based structural material with a zero-band gap and ultra-high specific surface area, has unique optoelectronic capabilities, promising a suitable basis for its application in the field of optical fiber sensing. Graphene optical fiber sensing has also been a hotspot in cross-research in biology, materials, medicine, and micro-nano devices in recent years, owing to prospective benefits, such as high sensitivity, small size, and strong anti-electromagnetic interference capability and so on. Here, the progress of optical fiber biochemical sensors based on graphene is reviewed. The fabrication of graphene materials and the sensing mechanism of the graphene-based optical fiber sensor are described. The typical research works of graphene-based optical fiber biochemical sensor, such as long-period fiber grating, Bragg fiber grating, no-core fiber and photonic crystal fiber are introduced, respectively. Finally, prospects for graphene-based optical fiber biochemical sensing technology will also be covered, which will provide an important reference for the development of graphene-based optical fiber biochemical sensors.
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Klimchitskaya, G. L. "Quantum field theory of the Casimir force for graphene." International Journal of Modern Physics A 31, no. 02n03 (January 20, 2016): 1641026. http://dx.doi.org/10.1142/s0217751x16410268.
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We present theoretical description of the Casimir interaction in graphene systems which is based on the Lifshitz theory of dispersion forces and the formalism of the polarization tensor in (2+1)-dimensional space-time. The representation for the polarization tensor of graphene allowing the analytic continuation to the whole plane of complex frequencies is given. This representation is used to obtain simple asymptotic expressions for the reflection coefficients at all Matsubara frequencies and to investigate the origin of large thermal effect in the Casimir force for graphene. The developed theory is shown to be in a good agreement with the experimental data on measuring the gradient of the Casimir force between a Au-coated sphere and a graphene-coated substrate. The possibility to observe the thermal effect for graphene due to a minor modification of the already existing experimental setup is demonstrated.
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Keel, Emma, Ammara Ejaz, Michael Mckinlay, Manuel Pelayo Garcia, Marco Caffio, Des Gibson, and Carlos García Núñez. "Three-dimensional graphene foam based triboelectric nanogenerators for energy systems and autonomous sensors." Nano Energy 112 (July 2023): 108475. http://dx.doi.org/10.1016/j.nanoen.2023.108475.
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Klimchitskaya, Galina L., and Vladimir M. Mostepanenko. "Casimir and Casimir-Polder Forces in Graphene Systems: Quantum Field Theoretical Description and Thermodynamics." Universe 6, no. 9 (September 9, 2020): 150. http://dx.doi.org/10.3390/universe6090150.
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We review recent results on the low-temperature behaviors of the Casimir-Polder and Casimir free energy an entropy for a polarizable atom interacting with a graphene sheet and for two graphene sheets, respectively. These results are discussed in the wide context of problems arising in the Lifshitz theory of van der Waals and Casimir forces when it is applied to metallic and dielectric bodies. After a brief treatment of different approaches to theoretical description of the electromagnetic response of graphene, we concentrate on the derivation of response function in the framework of thermal quantum field theory in the Matsubara formulation using the polarization tensor in (2 + 1)-dimensional space—time. The asymptotic expressions for the Casimir-Polder and Casimir free energy and entropy at low temperature, obtained with the polarization tensor, are presented for a pristine graphene as well as for graphene sheets possessing some nonzero energy gap Δ and chemical potential μ under different relationships between the values of Δ and μ. Along with reviewing the results obtained in the literature, we present some new findings concerning the case μ≠0, Δ=0. The conclusion is made that the Lifshitz theory of the Casimir and Casimir-Polder forces in graphene systems using the quantum field theoretical description of a pristine graphene, as well as real graphene sheets with Δ>2μ or Δ<2μ, is consistent with the requirements of thermodynamics. The case of graphene with Δ=2μ≠0 leads to an entropic anomaly, but is argued to be physically unrealistic. The way to a resolution of thermodynamic problems in the Lifshitz theory based on the results obtained for graphene is discussed.
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Jayasekera, Thushari, K. W. Kim, and M. Buongiorno Nardelli. "Electronic and Structural Properties of Turbostratic Epitaxial Graphene on the 6H-SiC (000-1) Surface." Materials Science Forum 717-720 (May 2012): 595–600. http://dx.doi.org/10.4028/www.scientific.net/msf.717-720.595.
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We propose an atomistic model to study the interface properties of mis-oriented (turbostratic) epitaxial graphene on SiC (000-1) surface. Using calculations from first principles, we compare the energetics, and structural/electronic properties of AB and turbostratic stacking sequences within a model based on the Si adatom surface reconstruction. Our calculations show that the systems with AB and turbostratic sequences are very close in energy, demonstrating the possibility of the observation of Moire patterns in epitaxial graphene on the C-face of SiC. The two-dimensional electron gas behavior is preserved in the epitaxial turbostratic graphene systems. However, there are deviations from the ideal turbostratic epitaxial graphene.
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Shahzad, Asif, Jae-Min Oh, Mudassar Azam, Jibran Iqbal, Sabir Hussain, Waheed Miran, and Kashif Rasool. "Advances in the Synthesis and Application of Anti-Fouling Membranes Using Two-Dimensional Nanomaterials." Membranes 11, no. 8 (August 9, 2021): 605. http://dx.doi.org/10.3390/membranes11080605.
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This article provides a comprehensive review of the recent progress in the application of advanced two-dimensional nanomaterials (2DNMs) in membranes fabrication and application for water purification. The membranes fouling, its types, and anti-fouling mechanisms of different 2DNMs containing membrane systems are also discussed. The developments in membrane synthesis and modification using 2DNMs, especially graphene and graphene family materials, carbon nanotubes (CNTs), MXenes, and others are critically reviewed. Further, the application potential of next-generation 2DNMs-based membranes in water/wastewater treatment systems is surveyed. Finally, the current problems and future opportunities of applying 2DNMs for anti-fouling membranes are also debated.
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Li, Cuimei, Tianya Li, Guangtao Yu, and Wei Chen. "Theoretical Investigation of HER and OER Electrocatalysts Based on the 2D R-graphyne Completely Composed of Anti-Aromatic Carbon Rings." Molecules 28, no. 9 (May 5, 2023): 3888. http://dx.doi.org/10.3390/molecules28093888.
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Based on the DFT calculations, two-dimensional (2D) R-graphyne has been demonstrated to have high stability and good conductivity, which can be conducive to the relevant electrocatalytic activity of the material. Different from the poor graphene, R-graphyne, which is completely composed of anti-aromatic structural units, can exhibit certain HER catalytic activity. In addition, doping the TM atoms in Group VIIIB can be considered an effective strategy to enhance the HER catalytic activity of R-graphyne. Particularly, Fe@R-graphyne, Os@R-graphyne, Rh@R-graphyne and Ir@R-graphyne can exhibit higher HER catalytic activities due to the formation of more active sites. Usually, the shorter the distance between the TM and C atoms is, the better the HER activity of the C-site is. Furthermore, doping Ni and Rh atoms of Group VIIIB can significantly improve the OER catalytic performance of R-graphyne. It can be found that ΔGO* can be used as a good descriptor for the OER activities of TM@R-graphyne systems. Both Rh@R-graphyne and Ni@R-graphyne systems can exhibit bifunctional electrocatalytic activities for HER/OER. In addition, all the relevant catalytic mechanisms are analyzed in detail. This work not only provides nonprecious and highly efficient HER/OER electrocatalysts, but also provides new ideas for the design of carbon-based electrocatalysts.
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Tian, Jingkun, Fei Xing, and Qiqian Gao. "Graphene-Based Nanomaterials as the Cathode for Lithium-Sulfur Batteries." Molecules 26, no. 9 (April 25, 2021): 2507. http://dx.doi.org/10.3390/molecules26092507.
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The global energy crisis and environmental problems are becoming increasingly serious. It is now urgent to vigorously develop an efficient energy storage system. Lithium-sulfur batteries (LSBs) are considered to be one of the most promising candidates for next-generation energy storage systems due to their high energy density. Sulfur is abundant on Earth, low-cost, and environmentally friendly, which is consistent with the characteristics of new clean energy. Although LSBs possess numerous advantages, they still suffer from numerous problems such as the dissolution and diffusion of sulfur intermediate products during the discharge process, the expansion of the electrode volume, and so on, which severely limit their further development. Graphene is a two-dimensional crystal material with a single atomic layer thickness and honeycomb bonding structure formed by sp2 hybridization of carbon atoms. Since its discovery in 2004, graphene has attracted worldwide attention due to its excellent physical and chemical properties. Herein, this review summarizes the latest developments in graphene frameworks, heteroatom-modified graphene, and graphene composite frameworks in sulfur cathodes. Moreover, the challenges and future development of graphene-based sulfur cathodes are also discussed.
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Kausar, Ayesha, Ishaq Ahmad, M. H. Eisa, and Malik Maaza. "Graphene Nanocomposites in Space Sector—Fundamentals and Advancements." C 9, no. 1 (March 3, 2023): 29. http://dx.doi.org/10.3390/c9010029.
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Graphene is one of the most significant carbon nanomaterials, with a one-atom-thick two-dimensional nanostructure. Like other nanocarbons, graphene has been used as a polymer reinforcement. This review explores the impact of graphene and graphene-based nanocomposites on aerospace applications. The fabrication and indispensable features of graphene-derived nanocomposites have been considered. Numerous polymers and nanocomposites have been employed for aerospace systems such as reinforced thermosetting/thermoplastic polymers and epoxy/graphene nanocomposites. Moreover, graphene-modified carbon-fiber-based composites have been discussed for the space sector. Aerospace nanocomposites with graphene have been investigated for superior processability, structural features, morphology, heat stability, mechanical properties, flame resistance, electrical/thermal conductivity, radiation protection, and adhesion applications. Subsequently, epoxy and graphene-derived nanocomposites have been explored for heat/mechanically stable aerospace engineering structures, radiation-shielding materials, adhesives, coatings, etc.
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Panin, Gennady N. "Low-Dimensional Layered Light-Sensitive Memristive Structures for Energy-Efficient Machine Vision." Electronics 11, no. 4 (February 17, 2022): 619. http://dx.doi.org/10.3390/electronics11040619.
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Layered two-dimensional (2D) and quasi-zero-dimensional (0D) materials effectively absorb radiation in the wide ultraviolet, visible, infrared, and terahertz ranges. Photomemristive structures made of such low-dimensional materials are of great interest for creating optoelectronic platforms for energy-efficient storage and processing of data and optical signals in real time. Here, photosensor and memristor structures based on graphene, graphene oxide, bismuth oxyselenide, and transition metal dichalcogenides are reviewed from the point of view of application in broadband image recognition in artificial intelligence systems for autonomous unmanned vehicles, as well as the compatibility of the formation of layered neuromorphic structures with CMOS technology.
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Raagulan, Kanthasamy, Bo Mi Kim, and Kyu Yun Chai. "Recent Advancement of Electromagnetic Interference (EMI) Shielding of Two Dimensional (2D) MXene and Graphene Aerogel Composites." Nanomaterials 10, no. 4 (April 8, 2020): 702. http://dx.doi.org/10.3390/nano10040702.
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The two Dimensional (2D) materials such as MXene and graphene, are most promising materials, as they have attractive properties and attract numerous application areas like sensors, supper capacitors, displays, wearable devices, batteries, and Electromagnetic Interference (EMI) shielding. The proliferation of wireless communication and smart electronic systems urge the world to develop light weight, flexible, cost effective EMI shielding materials. The MXene and graphene mixed with polymers, nanoparticles, carbon nanomaterial, nanowires, and ions are used to create materials with different structural features under different fabrication techniques. The aerogel based hybrid composites of MXene and graphene are critically reviewed and correlate with structure, role of size, thickness, effect of processing technique, and interfacial interaction in shielding efficiency. Further, freeze drying, pyrolysis and hydrothermal treatment is a powerful tool to create excellent EMI shielding aerogels. We present here a review of MXene and graphene with various polymers and nanomaterials and their EMI shielding performances. This will help to develop a more suitable composite for modern electronic systems.
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Xiao, Yang, Fang Luo, Yuchen Zhang, Feng Hu, Mengjian Zhu, and Shiqiao Qin. "A Review on Graphene-Based Nano-Electromechanical Resonators: Fabrication, Performance, and Applications." Micromachines 13, no. 2 (January 29, 2022): 215. http://dx.doi.org/10.3390/mi13020215.
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The emergence of graphene and other two-dimensional materials overcomes the limitation in the characteristic size of silicon-based micro-resonators and paved the way in the realization of nano-mechanical resonators. In this paper, we review the progress to date of the research on the fabrication methods, resonant performance, and device applications of graphene-based nano-mechanical resonators, from theoretical simulation to experimental results, and summarize both the excitation and detection schemes of graphene resonators. In recent years, the applications of graphene resonators such as mass sensors, pressure sensors, and accelerometers gradually moved from theory to experiment, which are specially introduced in this review. To date, the resonance performance of graphene-based nano-mechanical resonators is widely studied by theoretical approaches, while the corresponding experiments are still in the preliminary stage. However, with the continuous progress of the device fabrication and detection technique, and with the improvement of the theoretical model, suspended graphene membranes will widen the potential for ultralow-loss and high-sensitivity mechanical resonators in the near future.
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Pugno, N. "Non-linear statics and dynamics of nanoelectromechanical systems based on nanoplates and nanowires." Proceedings of the Institution of Mechanical Engineers, Part N: Journal of Nanoengineering and Nanosystems 219, no. 1 (March 1, 2005): 29–40. http://dx.doi.org/10.1243/174034905x5593.
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An analysis of the three-dimensional nanoelectromechanical systems (NEMS) is presented. Nanotubes could be a key one-dimensional element in future NEMS device; but they would be inadequate when two- or three-dimensional structures are required. A general free-energy-based formulation to treat statics and dynamics of three-dimensional NEMS, according to classical or quantum mechanics, is derved and presenteed; the method is then applied to nanoplates and nanowires. The equilibrium and stability of an elastic (e.g., graphene sheet) nanoplate-based NEMS under an electrical field and van der Waals forces (pauli's repulsion and large displacements are also discussed) are evaluated by minimizing the free energy and by the sign of the determinant of its Hessian matrix. The structural instability, arising at ythre so-called pull-in voltage, would correspond to the switch of the device. The amplitude and frequency of the thermal vibrations of the nanoplate are evaluated as a function of the applied voltage. The effect of the van der Waals forces on the NEMS dynamics is also presented. The amplitude and frequency of the oscillations at O K, from the uncertainty principle, are estimated.
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Ghosal, Supriya, and Debnarayan Jana. "Beyond T-graphene: Two-dimensional tetragonal allotropes and their potential applications." Applied Physics Reviews 9, no. 2 (June 2022): 021314. http://dx.doi.org/10.1063/5.0088275.
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Breakthrough of graphene dictates that decreasing dimensionality of the semiconducting materials can generate unusual electronic structures, excellent mechanical, and thermal characteristics with remarkable stability. Silicene, germanene, and stanene are the next 2D stable counterparts of other elements belonging to the same group. Since these monolayers possess hexagonal symmetry, scientists had already explored the possibility in the post graphene era of whether hexagonal symmetry was the main and utmost criterion for achieving Dirac cone. This motivation gave birth to T-graphene, a tetragonal network comprised of carbon atoms. However, T-graphene is not the only candidate for exhibiting Dirac fermion. In recent days, tetragonal monolayers of Si and Ge, i.e., T-Si and T-Ge, have been predicted to be stable. These 2D tetragonal allotropes remarkably possess double Dirac cones in their electronic band structure. As these monolayers possess buckling similar to silicene and germanene, the electronic bandgap can be easily introduced in the presence of an external electric field. Another technique to open bandgap is to apply strain in hydrogenated tetragonal networks. Tunable electronic properties in these tetragonal systems make them efficient for optoelectronics as well as thermoelectric applications. Moreover, due to delocalized π electrons, quantum dot systems comprised of tetragonal Si and Ge network show remarkable characteristics in the field of nonlinear optics. Recently, based on theoretical calculations, a bilayer T-graphene system is predicted with excellent mechanical strength relative to its monolayer variant. Not only group-IVA, group-VA elements also exhibit stable monolayer structures. Rather than T-graphene, T-Si, and T-Ge, these monolayers, however, possess intrinsic semiconducting properties, which enable them as a potential candidate for optoelectronic applications. Furthermore, several possible routes have been introduced to realize these systems experimentally. In this topical Review, we would critically explore the recent advancements of 2D tetragonal networks containing group-IVA and VA elements and their possible application perspectives in the field of thermoelectrics and nano-photonics.
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Memisoglu, Gorkem, Raghavan Chinnambedu Murugesan, Joseba Zubia, and Aleksey G. Rozhin. "Graphene Nanocomposite Membranes: Fabrication and Water Treatment Applications." Membranes 13, no. 2 (January 22, 2023): 145. http://dx.doi.org/10.3390/membranes13020145.
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Graphene, a two-dimensional hexagonal honeycomb carbon structure, is widely used in membrane technologies thanks to its unique optical, electrical, mechanical, thermal, chemical and photoelectric properties. The light weight, mechanical strength, anti-bacterial effect, and pollution-adsorption properties of graphene membranes are valuable in water treatment studies. Incorporation of nanoparticles like carbon nanotubes (CNTs) and metal oxide into the graphene filtering nanocomposite membrane structure can provide an improved photocatalysis process in a water treatment system. With the rapid development of graphene nanocomposites and graphene nanocomposite membrane-based acoustically supported filtering systems, including CNTs and visible-light active metal oxide photocatalyst, it is necessary to develop the researches of sustainable and environmentally friendly applications that can lead to new and groundbreaking water treatment systems. In this review, characteristic properties of graphene and graphene nanocomposites are examined, various methods for the synthesis and dispersion processes of graphene, CNTs, metal oxide and polymer nanocomposites and membrane fabrication and characterization techniques are discussed in details with using literature reports and our laboratory experimental results. Recent membrane developments in water treatment applications and graphene-based membranes are reviewed, and the current challenges and future prospects of membrane technology are discussed.
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Joe, Daniel J., Eunpyo Park, Dong Hyun Kim, Il Doh, Hyun-Cheol Song, and Joon Young Kwak. "Graphene and Two-Dimensional Materials-Based Flexible Electronics for Wearable Biomedical Sensors." Electronics 12, no. 1 (December 22, 2022): 45. http://dx.doi.org/10.3390/electronics12010045.
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The use of graphene and two-dimensional materials for industrial, scientific, and medical applications has recently received an enormous amount of attention due to their exceptional physicochemical properties. There have been numerous efforts to incorporate these two-dimensional materials into advanced flexible electronics, especially aimed for wearable biomedical applications. Here, recent advances in two-dimensional materials-based flexible electronic sensors for wearable biomedical applications with regard to both materials and devices are presented.
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Patole, Shashikant. "Green Approach for Fabrication of Holey Graphene Based Electrode for Supercapacitor Application." ECS Meeting Abstracts MA2022-01, no. 7 (July 7, 2022): 626. http://dx.doi.org/10.1149/ma2022-017626mtgabs.
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Holey graphene, also known as perforated graphene is formed generating in-plane holes in basal planes of graphene based materials. By combining the advantages of holes and graphene, holey graphene based materials have attained significant research interest in energy storage systems due to the high surface and high electrical conductivity. In the present work, the holey graphene nanosheets are synthesized using ‘metal catalyst activation strategy’ using a green chemistry approach. The synthesized holey graphene nanosheets are studied in detail using various comprehensive characterization and electrochemical analysis techniques. The green chemistry based fabricated holey graphene nanosheets are directly used as an electrode material in the supercapacitor application. In the supercapacitive study, the fabricated electrode exhibits an efficient performance (high capacitance, rate capacity and stability) than its pristine form (graphene) due to the formation of highly pores morphology which provides stupendous electroactive sites and resistance free pathways for ionic interaction and transport. The presented results provide a new platform for employing green approach for fabricating holey graphene based materials as an electrode in energy storage systems. Keywords: Holey Graphene, Pores, Nanosheets, Green Chemistry, Supercapacitors References: [1] Green chemistry based fabrication of holey graphene electrodes for high-performance supercapacitors, Materials Letters, 271, 127793 (2020). [2] Holey graphene: An emerging versatile material, J. Materials Chemistry A, 8, 918 (2020).
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Hernandez Linares, I. G., and G. Gonzalez de la Cruz. "Role of Plasmon Modes on the Optical Reflectivity of Graphene-Metallic Structures: A Theoretical Approach." Journal of Nano Research 60 (November 2019): 76–85. http://dx.doi.org/10.4028/www.scientific.net/jnanor.60.76.
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In recent years, the tunable plasmon modes in the terahertz region of a multilayer graphene structure interacting with a metallic film substrate have attracted significant interest motivated by the graphene´s unique optical and electronic properties and the possibility to enhance light-matter interaction. In this work, the plasmon waves in graphene layered systems on a conducting thin film are investigated, the hybrid graphene-metal metamaterialis surrounded by two semi-infinite materials with different dielectric constants ε1andε2, respectively. The dispersion relations of electronic collective excitations are calculated by the zeros of an effective dielectric constant obtained from a recursive relation for the amplitudes associated with the electric field between graphene layers in the metamaterial. Long-range Coulomb interactions based on the hybrid layered graphene-metal structure lead new set spectra of collective excitations. At long wavelength (q®0) the optical modes (w~q1/2)depend on the two-dimensional carrier density, the metallic thickness, the metallic substrate plasmon frequency, the number of the graphene layers and the dielectric constants in which the hybrid graphene-metal structure is embedded. This latter plays an important role in a wide range of applications such as a surface plasmon resonance biological sensors and terahertz surface plasmons in optically pumped graphene metamaterials.
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Chen, Guangze, Maryam Khosravian, Jose L. Lado, and Aline Ramires. "Designing spin-textured flat bands in twisted graphene multilayers via helimagnet encapsulation." 2D Materials 9, no. 2 (February 2, 2022): 024002. http://dx.doi.org/10.1088/2053-1583/ac4af8.
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Abstract Twisted graphene multilayers provide tunable platforms to engineer flat bands and exploit the associated strongly correlated physics. The two-dimensional nature of these systems makes them suitable for encapsulation by materials that break specific symmetries. In this context, recently discovered two-dimensional helimagnets, such as the multiferroic monolayer NiI2, are specially appealing for breaking time-reversal and inversion symmetries due to their nontrivial spin textures. Here we show that this spin texture can be imprinted on the electronic structure of twisted bilayer graphene by proximity effect. We discuss the dependence of the imprinted spin texture on the wave-vector of the helical structure, and on the strength of the effective local exchange field. Based on these results we discuss the nature of the superconducting instabilities that can take place in helimagnet encapsulated twisted bilayer graphene. Our results put forward helimagnetic encapsulation as a powerful way of designing spin-textured flat band systems, providing a starting point to engineer a new family of correlated moire states.
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Wang, Ying, Yue Shen, Xingya Wang, Zhiwei Shen, Bin Li, Jun Hu, and Yi Zhang. "Nanoscale mapping of dielectric properties based on surface adhesion force measurements." Beilstein Journal of Nanotechnology 9 (March 16, 2018): 900–906. http://dx.doi.org/10.3762/bjnano.9.84.
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The detection of local dielectric properties is of great importance in a wide variety of scientific studies and applications. Here, we report a novel method for the characterization of local dielectric distributions based on surface adhesion mapping by atomic force microscopy (AFM). The two-dimensional (2D) materials graphene oxide (GO), and partially reduced graphene oxide (RGO), which have similar thicknesses but large differences in their dielectric properties, were studied as model systems. Through direct imaging of the samples with a biased AFM tip in PeakForce Quantitative Nano-Mechanics (PF-QNM) mode, the local dielectric properties of GO and RGO were revealed by mapping their surface adhesion forces. Thus, GO and RGO could be conveniently differentiated. This method provides a simple and general approach for the fast characterization of the local dielectric properties of graphene-based materials and will further facilitate their applications in energy generation and storage devices.
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Ahmad, Varish, and Mohammad Omaish Ansari. "Antimicrobial Activity of Graphene-Based Nanocomposites: Synthesis, Characterization, and Their Applications for Human Welfare." Nanomaterials 12, no. 22 (November 14, 2022): 4002. http://dx.doi.org/10.3390/nano12224002.
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Graphene (GN)-related nanomaterials such as graphene oxide, reduced graphene oxide, quantum dots, etc., and their composites have attracted significant interest owing to their efficient antimicrobial properties and thus newer GN-based composites are being readily developed, characterized, and explored for clinical applications by scientists worldwide. The GN offers excellent surface properties, i.e., a large surface area, pH sensitivity, and significant biocompatibility with the biological system. In recent years, GN has found applications in tissue engineering owing to its impressive stiffness, mechanical strength, electrical conductivity, and the ability to innovate in two-dimensional (2D) and three-dimensional (3D) design. It also offers a photothermic effect that potentiates the targeted killing of cells via physicochemical interactions. It is generally synthesized by physical and chemical methods and is characterized by modern and sophisticated analytical techniques such as NMR, Raman spectroscopy, electron microscopy, etc. A lot of reports show the successful conjugation of GN with existing repurposed drugs, which improves their therapeutic efficacy against many microbial infections and also its potential application in drug delivery. Thus, in this review, the antimicrobial potentialities of GN-based nanomaterials, their synthesis, and their toxicities in biological systems are discussed.
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Cheng, Chi, Gengping Jiang, Christopher J. Garvey, Yuanyuan Wang, George P. Simon, Jefferson Z. Liu, and Dan Li. "Ion transport in complex layered graphene-based membranes with tuneable interlayer spacing." Science Advances 2, no. 2 (February 2016): e1501272. http://dx.doi.org/10.1126/sciadv.1501272.
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Investigation of the transport properties of ions confined in nanoporous carbon is generally difficult because of the stochastic nature and distribution of multiscale complex and imperfect pore structures within the bulk material. We demonstrate a combined approach of experiment and simulation to describe the structure of complex layered graphene-based membranes, which allows their use as a unique porous platform to gain unprecedented insights into nanoconfined transport phenomena across the entire sub–10-nm scales. By correlation of experimental results with simulation of concentration-driven ion diffusion through the cascading layered graphene structure with sub–10-nm tuneable interlayer spacing, we are able to construct a robust, representative structural model that allows the establishment of a quantitative relationship among the nanoconfined ion transport properties in relation to the complex nanoporous structure of the layered membrane. This correlation reveals the remarkable effect of the structural imperfections of the membranes on ion transport and particularly the scaling behaviors of both diffusive and electrokinetic ion transport in graphene-based cascading nanochannels as a function of channel size from 10 nm down to subnanometer. Our analysis shows that the range of ion transport effects previously observed in simple one-dimensional nanofluidic systems will translate themselves into bulk, complex nanoslit porous systems in a very different manner, and the complex cascading porous circuities can enable new transport phenomena that are unattainable in simple fluidic systems.
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Wu, Zhiqiang, Jun Wei, Rongzhen Dong, and Hao Chen. "A Three-Dimensional Strain Rosette Sensor Based on Graphene Composite with Piezoresistive Effect." Journal of Sensors 2019 (November 22, 2019): 1–12. http://dx.doi.org/10.1155/2019/2607893.
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Obtaining the internal stress and strain state of concrete to evaluate the safety and reliability of structures is the important purpose of concrete structural health monitoring. In this paper, a three-dimensional (3D) strain rosette sensor was designed and fabricated using graphene-based piezoresistive composite to measure the strains in concrete structures. The piezoresistive composite was prepared using reduced graphene oxide (RGO) as conductive filler, cellulose nanofiber (CNF) as dispersant and structural skeleton, and waterborne epoxy (WEP) as polymer matrix. The mechanical, electrical, and electromechanical properties of RGO-CNF/WEP composite were tested. The results show that the tensile strength, elastic modulus, and conductivity of the composite are greatly improved by the addition of RGO and CNF. The relative resistance change of composite films demonstrates high sensitivity to mechanical strain with gauge factors of 16-52. Within 4% strain, the piezoresistive properties of composites are stable with good linearity and repeatability. The sensing performance of the 3D strain rosette was tested. The measured strains are close to the actual strains of measure point in concrete, and the error is small. The RGO-CNF/WEP composite has excellent mechanical and piezoresistive properties, which enable the 3D strain rosette to be used as embedded sensor to measure the internal strain of concrete structures accurately.
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Karbalaei Akbari, Mohammad, Nasrin Siraj Lopa, Marina Shahriari, Aliasghar Najafzadehkhoee, Dušan Galusek, and Serge Zhuiykov. "Functional Two-Dimensional Materials for Bioelectronic Neural Interfacing." Journal of Functional Biomaterials 14, no. 1 (January 7, 2023): 35. http://dx.doi.org/10.3390/jfb14010035.
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Realizing the neurological information processing by analyzing the complex data transferring behavior of populations and individual neurons is one of the fast-growing fields of neuroscience and bioelectronic technologies. This field is anticipated to cover a wide range of advanced applications, including neural dynamic monitoring, understanding the neurological disorders, human brain–machine communications and even ambitious mind-controlled prosthetic implant systems. To fulfill the requirements of high spatial and temporal resolution recording of neural activities, electrical, optical and biosensing technologies are combined to develop multifunctional bioelectronic and neuro-signal probes. Advanced two-dimensional (2D) layered materials such as graphene, graphene oxide, transition metal dichalcogenides and MXenes with their atomic-layer thickness and multifunctional capabilities show bio-stimulation and multiple sensing properties. These characteristics are beneficial factors for development of ultrathin-film electrodes for flexible neural interfacing with minimum invasive chronic interfaces to the brain cells and cortex. The combination of incredible properties of 2D nanostructure places them in a unique position, as the main materials of choice, for multifunctional reception of neural activities. The current review highlights the recent achievements in 2D-based bioelectronic systems for monitoring of biophysiological indicators and biosignals at neural interfaces.
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Datta, Dibakar. "(Invited, Digital Presentation) Understanding Interfacial Chemo-Mechanics of Two-Dimensional Materials-Based Heterogeneous Functional Materials for Energy Storage." ECS Meeting Abstracts MA2022-01, no. 38 (July 7, 2022): 1655. http://dx.doi.org/10.1149/ma2022-01381655mtgabs.
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Two-dimensional (2D) materials and their heterostructures (2D + nD, n = 0,1,2,3) attracted enormous interest in wide range of applications including electrochemical systems, e.g., batteries. Electro-chemo-mechanics, the coupling of mechanics and electrochemistry, plays a crucial role in designing these systems. This talk considers battery as a model system and demonstrates the role of 2D materials in overcoming various interfacial electro-chemo-mechanical challenges. 2D materials are engineered as the van der Waals (vdW) “slippery” interface. For example, silicon (Si) electrodes can be placed over the graphene-coated current collector for Lithium-Ion Batteries (LIBs). This arrangement provides less stress build-up and less stress “cycling” on the vdW slippery substrate instead of a fixed interface. 2D materials such as MXenes can also be used to replace polymer binders, e.g., in Si-based LIBs. Our DFT studies show more stable performance and higher Coulombic efficiency for Si films deposited on graphene-coated nickel (i.e., slippery interface) than conventional nickel current collectors. The interface strength of monoclinic Se (selenium) is 0.43 J/m2, which is similar in magnitude in amorphous Si with graphene (0.41 J/m2). However, the interface strength of c-Se on a 3D aluminum (Al) current collector is higher (0.99 J/m2), suggesting a stronger adhesion for 3D/3D interface than 3D/2D interface. Furthermore, interface strength variation between a-Si and Ti3C2Tx MXenes are determined for various surface functional groups (Tx). The completely hydroxylated Ti3C2 has the highest interface strength of 0.60 J/m2 with a-Si. The talk also summarizes our recent efforts in developing High Dimensional Deep Learning Potential (HDDLP) to study interfacial electro-chemo-mechanics in 2D materials-based systems. Our computational results are in good agreement with experiments. Besides batteries, our comprehensive interface analyses are beneficial in advancing understanding of other 2D materials-based systems, e.g., sensors, fuel cells, solar cells, nanomedicine, soft-actuators, etc.
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Özkan, Doğuş, M. Cenk Özekinci, Zeynep Taşlıçukur Öztürk, and Egemen Sulukan. "Two Dimensional Materials for Military Applications." Defence Science Journal 70, no. 6 (October 12, 2020): 672–81. http://dx.doi.org/10.14429/dsj.70.15879.
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This paper particularly focuses on 2D materials and their utilization in military applications. 2D and heterostructured 2D materials have great potential for military applications in developing energy storage devices, sensors, electronic devices, and weapon systems. Advanced 2D material-based sensors and detectors provide high awareness and significant opportunities to attain correct data required for planning, optimization, and decision-making, which are the main factors in the command and control processes in the military operations. High capacity sensors and detectors or energy storage can be developed not only by using 2D materials such as graphene, hexagonal boron nitride (hBN), MoS2, MoSe2, MXenes; but also by combining 2D materials to obtain heterostructures. Phototransistors, flexible thin-film transistors, IR detectors, electrodes for batteries, organic photovoltaic cells, and organic light-emitting diodes have been being developed from the 2D materials for devices that are used in weapon systems, chemical-biological warfare sensors, and detection systems. Therefore, the utilization of 2D materials is the key factor and the future of advanced sensors, weapon systems, and energy storage devices for military applications.
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Kuznetsov, A. A., N. R. Maksimova, V. S. Kaimonov, G. N. Alexandrov, and S. A. Smagulova. "A New Approach To the Diagnosis of Point Mutations in Native DNA Using Graphene Oxide." Acta Naturae 8, no. 2 (June 15, 2016): 87–91. http://dx.doi.org/10.32607/20758251-2016-8-2-87-91.
Full textAbstract:
Development of new methods for the diagnosis of point mutations is a pressing issue. We have developed a new approach to the design of graphene oxide-based test systems for the diagnosis of point mutations in native DNA. This new approach is based on the use of graphene oxide for the adsorption and quenching of fluorescently labeled primers in a post-amplification PCR mixture followed by detection of fluorescently labeled PCR products. It is possible to detect fluorescently labelled amplicons in the presence of an excess of primers in a PCR product solution due to the different affinities of single-stranded and double-stranded DNA molecules to graphene oxide, as well as the ability of graphene oxide to act as a quencher of the fluorophores adsorbed on its surface. The new approach was tested by designing a graphene oxide-based test system for the DNA diagnosis of the point mutation associated with the development of the 3M syndrome in Yakuts. The developed approach enables one to design graphene oxide-based test systems suitable for the diagnosis of any point mutations in native DNA.