Applications Of Graphene Research Articles

Robust intrinsic quantum spin Hall states in transition metal M-doped graphene (M = Ti, Zr, Hf)

Abstract Graphene is a promising candidate for spintronics and low-dissipation quantum electronic device applications. However, its excessively weak spin-orbit coupling interaction (~ 24.0 μeV) makes the electric field modulation of spin currents almost impossible and the experimental observation of spin-polarized edge states in topological energy gap very challenging. These difficulties limit the practical applications of graphene. In this work, the electronic structures and topological properties of group IVB transition metal M-doped graphene (M = Ti, Zr, Hf) have been studied by first-principles calculations. Taking the Hf-doped graphene as an example, in the absence of spin-orbit coupling, this system possesses six equivalent Dirac points near the Fermi level in the Brillouin zone, owing to C 3z and inversion symmetries. These Dirac points exhibit linear dispersion in a wide energy range (about 1.00 eV), making this material a Dirac semimetal. When spin-orbit coupling interaction is considered, the Dirac points of this system are gapped with a spin-orbit gap of 16.4 meV, which is three orders of magnitude larger than that of graphene. Furthermore, the system is an intrinsic quantum spin Hall insulator with the nontrivial topological index Z 2 = 1. We also propose that the nontrivial topological properties are robust in a wide biaxial strain range from −5% to 5% and the spin-orbit gap further increases to 37.7 meV under 5% strain. Compared to the pristine graphene, our research has greatly enhanced spin-orbit coupling in this system with its nontrivial topological property preserved, which is crucial for the development of graphene-based spin field effect transistors. Moreover, such graphene-based robust topological material designs could also pave the way for a new generation of spintronics, ultra-low-dissipation electronics and quantum information processing devices.

Application of Graphene and Chitosan in Water Splitting/Catalysis

Application of Graphene and Chitosan in Water Splitting/Catalysis

Applications and prospects of graphene and its derivatives in bone repair

To summarize the latest research progress of graphene and its derivatives (GDs) in bone repair. The relevant research literature at home and abroad in recent years was extensively accessed. The properties of GDs in bone repair materials, including mechanical properties, electrical conductivity, and antibacterial properties, were systematically summarized, and the unique advantages of GDs in material preparation, functionalization, and application, as well as the contributions and challenges to bone tissue engineering, were discussed. The application of GDs in bone repair materials has broad prospects, and the functionalization and modification technology effectively improve the osteogenic activity and material properties of GDs. GDs can induce osteogenic differentiation of stem cells through specific signaling pathways and promote osteogenic activity through immunomodulatory mechanisms. In addition, the parameters of GDs have significant effects on the cytotoxicity and degradation behavior. GDs has great potential in the field of bone repair because of its excellent physical and chemical properties and biological properties. However, the cytotoxicity, biodegradability, and functionalization strategies of GDs still need to be further studied in order to achieve a wider application in the field of bone tissue engineering.

Graphene in Lithium-Sulfur Batteries: Challenges, Improvement Strategies and Future Prospects

Lithium-sulfur batteries have advantages such as high theoretical energy density, but suffer from poor sulfur conductivity, polysulfur shuttle effect and volume expansion. Graphene shows potential to enhance the performance of lithium-sulfur batteries due to its high electrical conductivity and large specific surface area. This paper explores the application of graphene in lithium-sulfur batteries through a literature review. Graphene can be used to modify cathode materials, which can be prepared by methods include chemical vapor deposition, hydrothermal synthesis and sol-gel method, so as to improve the electrical conductivity and inhibit the shuttle effect. The addition of graphene to the diaphragm facilitates the formation of a physical barrier layer, which can effectively impede polysulfide migration, enhance ion transport properties, and augment the mechanical strength and stability of the diaphragm. After modification of the electrolyte, graphene enhances ionic conductivity, inhibits polysulfide shuttling, and improves the performance of the electrode/electrolyte interface. However, there are still some challenges, such as the difficulty of completely eliminating the polysulfide shuttle effect, the high cost, and the stability of the electrode structure to be improved. In the future, the composite process of graphene and sulfur, the development of low-cost and high-performance graphene materials, and the comprehensive application of graphene modification strategies should be optimized to promote the development of lithium-sulfur battery technology.

Enhanced Near-Infrared Fluorescence Emission near a Graphene-Metal Hybrid Structure.

Plasmon resonance plays an important role in improving the detection of biomolecules, and it is one of the focuses of research to use metal plasmon resonance to achieve fluorescence enhancement and to improve detection sensitivity. However, the problems of nondynamic tuning and fluorescence quenching of metal plasmon resonance need to be solved. Graphene surface plasmon resonance can be dynamically controlled, and the graphene adsorption of fluorescent molecules can avoid fluorescence quenching and greatly improve the fluorescence emission intensity. The graphene-metal hybrid structure designed in this work can solve the above two problems well, and the plasmon resonance can improve the fluorescence emission efficiency of molecules on the surface of graphene and improve the sensitivity of biological detection. At the same time, graphene nanoribbons in our hybrid structure do not require patterning, which greatly lowers the threshold for graphene application in biosensing.

Applications of graphene in quantum computing

Applications of graphene in quantum computing

Research and application of graphene in construction

Research and application of graphene in construction

Application of graphene in semiconductor power electronic devices

Application of graphene in semiconductor power electronic devices

Roles of doping in enhancing the performance of graphene/graphene-like semiconductors

Graphene is renowned for its excellent chemical, thermal, mechanical, electrical, and optical properties, which arise from its unique bonding structure. However, graphene is intrinsically a zero-bandgap material, limiting its development in the field of flexible nanoelectronics. To expand the range of applications for graphene in electronic devices, it is crucial to develop the strategies for inducing a bandgap. One of the most effective methods is chemical doping. Doping not only alters the electronic properties of graphene by modifying its inherent gapless nature but also engenders new materials with distinctive and potentially synergistic characteristics. Although there are many reviews on the doped graphene, there is a rare one to discuss the role of doping in enhancing the performance of graphene-based semiconductors. This paper reviews various doping types and their impacts on graphene, emphasizing the effects of boron (B) doping, nitrogen (N) doping, oxygen-group doping, other non-metallic atom or atomic pair doping, and metallic doping. We will further discuss how these dopants affect the geometry, electronic structure, and mechanical properties of graphene. It is expected to be meaningful for further understanding the nature of doped graphene and building new graphene-like structures.

Application of Graphene Composites in Flexible Electrons

With the development of science and technology, graphene materials have come into the public view, especially in flexible electronics and play a key role, which has attracted the public’s attention. Because of its good electrical conductivity, high light transmittance and good flexibility, it has a high application value in the research and development of supercapacitors and epidermal electronics.This paper summarizes the structure and properties of graphene, discusses the application of graphene in supercapacitors and other aspects, describes the research progress and direction of graphene composite in flexible electrons in recent years, and the future development and prediction of graphene composite in flexible electrons. It is found that graphene has significant technical advantages and broad application prospects in the field of flexible electronics. The future prospects of graphene are still broad, and the joint efforts of scientific research and industry are expected to promote the further development and wide application of graphene technology.

Flexible Electronic Skin Based on Graphene and Its Composites

Flexible electronic skin, as an important part of bionic technology, has a wide range of applications in the fields of wearable devices, intelligent robots, and bionic prostheses. Graphene, as a two-dimensional material with excellent electrical conductivity, mechanical flexibility and chemical stability, shows great potential in flexible electronic skin. This paper reviews recent advances in flexible electronic skin based on graphene and its composites, presenting the unique physicochemical properties of graphene and its advantages in flexible sensor materials. This paper discusses in detail the application of graphene and its composites in flexible sensors, including pressure sensors, humidity sensors, and flexible supercapacitors. This paper summarizes the challenges faced in current research, such as the cost and process complexity of material preparation, increased sensor integration, and issues of long-term stability. In addition, this paper proposes future directions, including the large-scale preparation of low-cost and high-performance graphene materials, the improvement of sensor sensitivity and durability, the optimization of graphene composites, and the realization of multifunctional and integrated flexible e-skin systems. Valuable references are provided to further promote the practical applications of graphene-based flexible electronic skin in the fields of medical monitoring, bionic technology and smart wearable.

In Ukrainian

Due to its excellent electrical, mechanical, thermal and optical properties, graphene has attracted much interest since it was discovered in 2004. Its two-dimensional nature and other remarkable properties meet the needs of surface plasmons and have greatly enriched the field of plasmonics. The paper will review recent advances and applications of graphene in plasmonic, including theoretical mechanisms, experimental observations, and meaningful applications. Due to its flexibility and good tunability, graphene can be a promising plasmonic material as an alternative to noble metals. Optical conversion, plasmonic metamaterials, light harvesting, etc. have already been realized in graphene-based devices, which are useful for applications in electronics, optics, energy storage, THz technology, etc. In addition, the excellent biocompatibility of graphene makes it a very good candidate for applications in biotechnology and medical science. Surface plasmons in graphene offer a compelling route to many useful photonic technologies. As a plasmonic material, graphene offers several intriguing properties, such as excellent electro-optic tunability, crystal stability, large optical nonlinearity, and extremely high electromagnetic field concentration. Thus, recent demonstrations of surface plasmon excitation in graphene using near-infrared light scattering] have attracted great interest. Here we present an all-optical plasmonic coupling scheme that takes advantage of the intrinsic nonlinear optical response of graphene. To generate plasmons, pulses of visible light in a free in-plane graphene sheet are used using difference frequency mixing of the waves to match both the wave vector and the energy of the surface wave. By carefully controlling the phase with matching conditions, we show that it is possible to excite surface plasmons with a defined wave vector and direction in a wide frequency range with high photon efficiency. Prospects for the practical use of graphene in plasmonics are discussed.

Graphene Applications in Sensors: Performance Optimization and Prospects

A sensor, as a detection device, is able to receive information and convert it into an electrical signal or other form of signal for output. In today's era of rapid development of intelligence, digitalization and networking, sensors have become the core tool for obtaining information. As technology advances, higher standards have been set for sensor sensitivity and application breadth. Graphene, a single-layer thin film material composed of carbon atoms arranged in a hexagonal honeycomb, has attracted much attention in the engineering industry because of its unique structure and its excellent electrical and mechanical properties. Among the many potential applications, sensors are seen as one of the most promising application areas for graphene.In this paper, the basic structural characteristics and unique properties of graphene are first outlined, and then the specific application cases in many fields such as biomedical sensors, flexible pressure sensors and photoelectric chemical sensors are discussed in detail, and the wide use of graphene materials is demonstrated by examples. At the same time, the different preparation methods of graphene are compared and analyzed, and the challenges faced by graphene sensors in the commercialization process are pointed out. Finally, a series of suggestions and prospects are put forward for the future development path of graphene sensors.

Optical Properties of S-doped and S, N Co-doped Graphene Quantum Dots and Application

In recent years, carbon-based quantum dots, including carbon quantum dots (CQDs) and graphene quantum dots (GQDs), have been widely researched as new alternatives to conventional antibacterial agents. The structural characteristics and properties of the materials can also be tuned and controlled by changing the shape and size of the GQDs. Effective doping with heteroatoms can also tune the optical, electronic and electrochemical properties, etc., of GQDs. In this report, we study and synthesize sulfur (S)-doped graphene quantum dots and sulfur (S), nitrogen (N)-co-doped-graphene quantum dots using a simple method that requires minimal energy and is environmentally friendly. By controlling the absorption and luminescence spectra in the desired wavelength range, S, N-GQDs can easily be applied as biocides for common bacteria such as E. coli and S. aureus, also presented in this report.

Stacking Engineering toward Giant Second Harmonic Generation in Twisted Graphene Superstructures.

The nonlinear optical response in graphene is finding increasing applications in nanophotonic devices. The activation and enhancement of second harmonic generation (SHG) in graphene, which is generally forbidden in monolayer and AB-stacked bilayer graphene due to their centrosymmetry, is of urgent need for nanophotonic applications. Here, we present a comprehensive study of SHG performance of twisted multilayer graphene structures based on stacking engineering. It is found that the modulation of in-plane and out-of-plane SHG susceptibility components by stacking few-layer graphene is essential in producing giant SHG response in twisted multilayer graphene. Giant SHG intensity in twisted multilayer graphene is observed, reaching nearly 10 times that of monolayer MoS2 under 1064 nm excitation, which significantly outperformed graphene structures reported to date. Our findings present a facile and effective approach to enhance SHG in graphene structures, showing promise for future application of graphene in second harmonic nanophotonic devices as well as prospects for the study of SHG among two-dimensional (2D) structures in general.

Mizoroki-Heck Cross-Coupling: Mechanism, Catalysis with Transition Metals and Graphene Synergistic Catalysts and Applications

Upon examining the progression of organic chemistry and comprehending its fundamental nature, it becomes evident that carbon–carbon bond-forming processes hold unparalleled significance in creating this field of scientific inquiry. The Diels–Alder, Grignard, and Wittig reactions are three notable examples of chemical processes that have played significant roles in the development of modern chemical synthesis throughout the past century. During the last quarter of the 20th century, a novel category of carbon–carbon bond-forming reactions emerged, which relied on transition-metal catalysts and substantiated to be exceedingly effective instruments in the field of synthesis. One of the most researched cross-coupling reactions is the Mizoroki-Heck reaction, which has garnered significant attention and was conferred the Nobel Prize in Chemistry. This review focuses on the examination of various catalysts employed in Mizoroki-Heck cross coupling processes, namely those composed of transition metals and reduced graphene oxide (rGO). The selected examples serve as compelling illustrations of the significant efficacy of these catalysts in the realm of complete synthesis, hence emphasizing their prospective utility in the field of chemical synthesis.

Preparation of Graphene Using Rice Husk via Pyrolysis Technique for CO<sub>2</sub> Adsorption

Graphene is the only carbon allotrope in which every carbon atom is densely connected to its neighbours by an electronic cloud, raising various quantum physics concerns. In recent years, many researchers have focused their efforts on developing more efficient methods for synthesizing graphene. However, only few methods can simultaneously synthesize mass-produced, cost-effective, and high-quality graphene. In this study, we are emphasizing the use of rice husk (RH) as the raw material to prepare graphene by using two-step pyrolysis. Zinc chloride (ZnCl2) is an example of an activating agent that is used to improve the efficiency of the synthesis of graphene from rice husk. After conducting pre-treatment of rice husk, the first stage of pyrolysis was conducted by varying the ratio of ZnCl2 to the RH (1:1, 2:1, 3:1) at a carbonization temperature of 500 °C for 1 hour, followed by second-stage pyrolysis under 900 °C for 90 minutes and post-treatment. The findings of the characterizations, which included yield analysis, scanning electron microscopy (SEM) and Raman spectroscopy, Brunauer-Emmett-Teller (BET), and CO2 adsorption analysis, revealed the impacts of the ZnCl2 as activating agent, on the yield and graphitic structure of graphene and the potential application of graphene as a CO2 adsorbent. Raman spectroscopy confirmed the graphitic properties of graphene synthesized in all samples with RH1:1 produced the best quality of graphene due to its low ID/IG intensity ratio (0.8913) and the highest I2D/IG intensity at 0.24. In addition, RH1:1 exhibited the highest surface area, whereby the highest total pore and micropore volume is contributing to the highest CO2 adsorption capacity of 8.73 mmol/g. This proves that the activating agent ratio has significant effects on the graphene quality produced from rice husk as well as the adsorption performance.

Spontaneous emergence of straintronics effects and striped stacking domains in untwisted three-layer epitaxial graphene

Emergent electronic phenomena, from superconductivity to ferroelectricity, magnetism, and correlated many-body band gaps, have been observed in domains created by stacking and twisting atomic layers of Van der Waals materials. In graphene, emergent properties have been observed in ABC stacking domains obtained by exfoliation followed by expert mechanical twisting and alignment with the desired orientation, a process very challenging and nonscalable. Here, conductive atomic force microscopy shows in untwisted epitaxial graphene grown on SiC the surprising presence of striped domains with dissimilar conductance, a contrast that demonstrates the presence of ABA and ABC domains since it matches exactly the conductivity difference observed in ABA/ABC domains in twisted exfoliated graphene and calculated by density functional theory. The size and geometry of the stacking domains depend on the interplay between strain, solitons crossing, and shape of the three-layer regions. Interestingly, we demonstrate the growth of three-layer regions in which the ABA/ABC stacking domains self-organize in stable stripes of a few tens of nanometers. The growth-controlled production of isolated and stripe-shaped ABA/ABC domains open the path to fabricate quantum devices on these domains. These findings on self-assembly formation of ABA/ABC epitaxial graphene stripes on SiC without the need of time-consuming and nonscalable graphene exfoliation, alignment, and twisting provide different potential applications of graphene in electronic devices.

Graphene Oxide and Based Materials: Synthesis, Properties, and Applications – A Comprehensive Review

Graphene-based materials have garnered significant interest in the burgeoning field of contemporary flexible and bendable technologies. Graphene has emerged as a prime candidate for the development of flexible electronics due to its outstanding electrical, mechanical, and optical properties, coupled with the ease of functionalizing its derivatives. This review provides an exhaustive analysis of the latest advancements in the synthesis and applications of graphene-based composites. Exceptional properties of Graphene including high thermal conductivity, chemical stability, optical transparency, high current density, and increased surface area, have broad implications across thermodynamics, chemistry, optics, and mechanics. The growing use of graphene oxide materials across various industries has fueled a surge in interest. The synthesis of graphene oxide compounds follows established procedures such as those by Brodie, Staudenmaier, and Tour, with ongoing discussions on large-scale production using various oxidants. Recent developments have led to numerous new, enhanced, and modified Hummers techniques for producing graphene oxide. Graphene oxide (GO) serves as a crucial foundational material for a wide range of applications, including energy storage, water purification, and as a composite in biosensors, electronics, and hazardous gas removal. This review delves into these applications, highlighting GO’s role in improving the efficiency and performance of these technologies. Additionally, the paper addresses the current challenges and obstacles in the development and application of graphene, providing insights into potential solutions and future research directions. By offering a comprehensive and practical database, this review aims to facilitate the future development of graphene-based composite materials, driving innovation and advancements in various high-impact applications.

Application Research Progress of Nanomaterial Graphene and its Derivative Complexes in Tumor Diagnosis and Therapy.

Functional nanomaterial graphene and its derivatives have attracted considerable attention in many fields because of their unique physical and chemical properties. Most notably, graphene has become a research hotspot in the biomedical field, especially in relation to malignant tumors. In this study, we briefly review relevant research from recent years on graphene and its derivatives in tumor diagnosis and antitumor therapy. The main contents of the study include the graphene-derivative diagnosis of tumors in the early stage, graphene quantum dots, photodynamics, MRI contrast agent, acoustic dynamics, and the effects of ultrasonic cavitation and graphene on tumor therapy. Moreover, the biocompatibility of graphene is briefly described. This review provides a broad overview of the applications of graphene and its derivatives in tumors. Conclusion, graphene and its derivatives play an important role in tumor diagnosis and treatment.