Journal articles: 'Nanostructure - Graphene'

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Fan, Jiakang. "The realization of a broadband light absorber via the synergistic effect of graphene and silicon nanostructures." Journal of Physics: Conference Series 2285, no. 1 (June 1, 2022): 012001. http://dx.doi.org/10.1088/1742-6596/2285/1/012001.

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Abstract Due to the increasing demand for clean energy, it becomes more and more necessary to find out more efficient ways to generate clean energy. Because of this, the light conversion efficiency of different materials has been largely studied. The purpose of the study is to investigate how the silicon pyramidal nanostructures and graphene layer affect the light-absorbing performance of materials and achieve a broadband light absorber. Simulations of four experimental groups, including both with nanostructure and graphene, with nanostructure and without graphene, without nanostructure and with graphene, both without nanostructure and graphene, are done to obtain and compare the data through the method of finite difference time domain (FDTD). By analyzing the simulation results, it is found that the silicon pyramidal structures can improve the light absorption within the range of visible light. Moreover, the presence of graphene layers can improve the light absorption within the range of near-infrared to infrared light. The number of layers can also have effects on light absorption.

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Avila, Antonio F., Aline M. de Oliveira, Viviane C. Munhoz, and Glaucio C. Pereira. "Graphene-CNTs into Neuron-Synapse Like Configuration a New Class of Hybrid Nanocomposites." Advanced Materials Research 1119 (July 2015): 116–20. http://dx.doi.org/10.4028/www.scientific.net/amr.1119.116.

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This paper describes the experimental procedures for developing and testing of a new class of hybrid nanocomposites, the neuron-synapse configuration ones. Two carbon based nanostructures, multiwall carbon nanotubes and multi-layered graphene, were incorporated to carbon epoxy laminated. The processing technique employed which includes a combination of sonication and high shear mixing allows the formation of a neuron-synapse nanostructure. X-ray diffractometry indicates that multi-layer graphene (MLG) has an average diameter close to 22 nm. TEM observations and raman spectroscopy revealed a thickness of 10 graphene layers, and a hybrid nanostructure where MWNT interpenetrated the MLG nanostructure. The hybrid nanostructure seems to be linked by Van der Walls bonds. This could be the reason for large crack density generated during short-beam bending tests. No significant stiffness changes were observed in both, tensile and bending, tests, while tensile strength were improved by 19% with 1 wt.% addition of graphene the interlaminar shear strength, was increased by 22% with the addition of MWNTs and 2.5% with the graphene (1 wt.%) and MWNT (0.3 wt.%) together.

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Wallace, Steaphan M., Thiyagu Subramani, Wipakorn Jevasuwan, and Naoki Fukata. "Conversion of Amorphous Carbon on Silicon Nanostructures into Similar Shaped Semi-Crystalline Graphene Sheets." Journal of Nanoscience and Nanotechnology 21, no. 9 (September 1, 2021): 4949–54. http://dx.doi.org/10.1166/jnn.2021.19329.

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Graphene sheets displaying partial crystallinity and nanowire structures were formed on a silicon substrate with silicon nanowires by utilizing an amorphous carbon source. The carbon source was deposited onto the silicon nanostructured substrate by breaking down a polymer precursor and was crystallized by a nickel catalyst during relatively low temperature inert gas annealing. The resulting free-standing graphene-based material can remain on the substrate surface after catalyst removal or can be removed as a separate film. The film is flexible, continuous, and closely mimics the silicon nanostructure. This follows research on similar solid carbon precursor derived semi-crystalline graphene synthesis procedures and applies it to complex silicon nanostructures. This work examined the progression of the carbon, finding that it migrates through the thin film catalyst and forms the graphene only on the other side, and that the process can successfully be used to form 3D shaped graphene films. Semi-crystalline graphene has the possible application of being flexible transparent electrodes, and the 3D shaping opens the possibility of more complex configurations and applications.

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Fujii, Shintaro, Maxim Ziatdinov, Misako Ohtsuka, Koichi Kusakabe, Manabu Kiguchi, and Toshiaki Enoki. "Role of edge geometry and chemistry in the electronic properties of graphene nanostructures." Faraday Discuss. 173 (2014): 173–99. http://dx.doi.org/10.1039/c4fd00073k.

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The geometry and chemistry of graphene nanostructures significantly affects their electronic properties. Despite a large number of experimental and theoretical studies dealing with the geometrical shape-dependent electronic properties of graphene nanostructures, experimental characterisation of their chemistry is clearly lacking. This is mostly due to the difficulties in preparing chemically-modified graphene nanostructures in a controlled manner and in identifying the exact chemistry of the graphene nanostructure on the atomic scale. Herein, we present scanning probe microscopic and first-principles characterisation of graphene nanostructures with different edge geometries and chemistry. Using the results of atomic scale electronic characterisation and theoretical simulation, we discuss the role of the edge geometry and chemistry on the electronic properties of graphene nanostructures with hydrogenated and oxidised linear edges at graphene boundaries and the internal edges of graphene vacancy defects. Atomic-scale details of the chemical composition have a strong impact on the electronic properties of graphene nanostructures,i.e., the presence or absence of non-bonding π states and the degree of resonance stability.

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Wu, Shiyun, Kaimin Fan, Minpin Wu, and Guangqiang Yin. "Two-dimensional MnO2/graphene hybrid nanostructures as anode for lithium ion batteries." International Journal of Modern Physics B 30, no. 27 (October 17, 2016): 1650208. http://dx.doi.org/10.1142/s0217979216502088.

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Using density functional theory, we have investigated the adsorption and diffusion of lithium on the two-dimensional MnO2/graphene hybrid nanostructures. The simulation results show that the adsorption energy is increased compared with pure graphene and monolayer MnO2. At the same time, the diffusion barrier is greatly reduced as lithium diffuses on the graphene side. The results indicate that the MnO2/graphene hybrid nanostructure can be used as a good anode material for lithium ion batteries.

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Tamm, Aile, Tauno Kahro, Helle-Mai Piirsoo, and Taivo Jõgiaas. "Atomic-Layer-Deposition-Made Very Thin Layer of Al2O3, Improves the Young’s Modulus of Graphene." Applied Sciences 12, no. 5 (February 27, 2022): 2491. http://dx.doi.org/10.3390/app12052491.

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Nanostructures with graphene make them highly promising for nanoelectronics, memristor devices, nanosensors and electrodes for energy storage. In some devices the mechanical properties of graphene are important. Therefore, nanoindentation has been used to measure the mechanical properties of polycrystalline graphene in a nanostructure containing metal oxide and graphene. In this study the graphene was transferred, prior to the deposition of the metal oxide overlayers, to the Si/SiO2 substrate were SiO2 thickness was 300 nm. The atomic layer deposition (ALD) process for making a very thin film of Al2O3 (thickness comparable with graphene) was applied to improve the elasticity of graphene. For the alumina film the Al(CH3)3 and H2O were used as the precursors. According to the micro-Raman analysis, after the Al2O3 deposition process, the G-and 2D-bands of graphene slightly broadened but the overall quality did not change (D-band was mostly absent). The chosen process did not decrease the graphene quality and the improvement in elastic modulus is significant. In case the load was 10 mN, the Young’s modulus of Si/SiO2/Graphene nanostructure was 96 GPa and after 5 ALD cycles of Al2O3 on graphene (Si/SiO2/Graphene/Al2O3) it increased up to 125 GPa. Our work highlights the correlation between nanoindentation and defects appearance in graphene.

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Wang, Wei, Shirui Guo, Isaac Ruiz, Mihrimah Ozkan, and Cengiz S. Ozkan. "Synthesis of Three Dimensional Carbon Nanostructure Foams for Supercapacitors." MRS Proceedings 1451 (2012): 85–90. http://dx.doi.org/10.1557/opl.2012.1330.

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ABSTRACTIn this work, we demonstrated the growth of three dimensional graphene/carbon nanotubes hybrid carbon nanostructures on metal foam through a one-step chemical vapor deposition (CVD). The as-grown three dimensional carbon nanostructure foams can be potentially used as the electrodes of energy storage devices such as supercapacitors and batteries. During the CVD process, the carbon nanostructures are grown on highly porous nickel foam to form a high surface area 3-D carbon nanostructure by introducing a mixture precursor gases (H2, C2H2). The surface morphology was investigated by scanning electron microscopy (SEM) and the results demonstrated relatively homogeneous and densely packed 3-D carbon nanostructure. The quality was characterized by Raman spectroscopy. To further increase the capacitive capability the supercapacitors were fabricated based on the electrodes of carbon nanostructure foam and cyclic voltammetry, charge-discharge, and electrochemical impedance spectroscopy (EIS) were conducted to determine their performance.

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Bi, Kaixi, Jiliang Mu, Wenping Geng, Linyu Mei, Siyuan Zhou, Yaokai Niu, Wenxiao Fu, Ligang Tan, Shuqi Han, and Xiujian Chou. "Reliable Fabrication of Graphene Nanostructure Based on e-Beam Irradiation of PMMA/Copper Composite Structure." Materials 14, no. 16 (August 17, 2021): 4634. http://dx.doi.org/10.3390/ma14164634.

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Graphene nanostructures are widely perceived as a promising material for fundamental components; their high-performance electronic properties offer the potential for the construction of graphene nanoelectronics. Numerous researchers have paid attention to the fabrication of graphene nanostructures, based on both top-down and bottom-up approaches. However, there are still some unavoidable challenges, such as smooth edges, uniform films without folds, and accurate dimension and location control. In this work, a direct writing method was reported for the in-situ preparation of a high-resolution graphene nanostructure of controllable size (the minimum feature size is about 15 nm), which combines the advantages of e-beam lithography and copper-catalyzed growth. By using the Fourier infrared absorption test, we found that the hydrogen and oxygen elements were disappearing due to knock-on displacement and the radiolysis effect. The graphene crystal is also formed via diffusion and the local heating effect between the e-beam and copper substrate, based on the Raman spectra test. This simple process for the in-situ synthesis of graphene nanostructures has many promising potential applications, including offering a way to make nanoelectrodes, NEMS cantilever resonant structures, nanophotonic devices and so on.

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Li, Jia Ye, Jin Feng Zhu, and Qing H. Liu. "Tunable Properties of Three-Dimensional Graphene-Loaded Plasmonic Absorber Using Plasmonic Nanoparticles." Materials Science Forum 860 (July 2016): 29–34. http://dx.doi.org/10.4028/www.scientific.net/msf.860.29.

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We demonstrate a three-dimensional nanostructure design by combining graphene and conventional plasmonic nanostructures, to achieve the high absorbance in the visible region. Furthermore, the peak position and bandwidth of graphene absorption spectra are tunable in a wide wavelength range through a specific structural configuration. Comparing the results of two structures which is based on different materials, Gold and Silver. The structure made of Silver present a better performance. These results imply that graphene in combination with plasmonic perfect absorbers have a promising potential for developing advanced nanophotonic devices.

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Loginos, Panagiotis, Anastasios Patsidis, and Vasilios Georgakilas. "UV-Cured Poly(Ethylene Glycol) Diacrylate/Carbon Nanostructure Thin Films. Preparation, Characterization, and Electrical Properties." Journal of Composites Science 4, no. 1 (January 1, 2020): 4. http://dx.doi.org/10.3390/jcs4010004.

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Carbon nanoallotropes such as carbon nanotubes, graphene, and their derivatives have been combined with a plethora of polymers in the last years to develop new composite materials with interesting properties and applications. However, the area of photopolymer composites with carbon nanostructures has not been analogously explored. In the present article, we study the photopolymerization of poly(ethylene glycol)diacrylate (PEGDA) enriched with different carbon nanoallotropes like graphene, pristine and chemically modified carbon nanotubes (CNTs and fCNTs), and a hybrid of graphene and CNTs. The products were characterized by several microscopic and spectroscopic techniques and the electrical conductivity was studied as a function of the concentrations of carbon nanoallotropes. In general, stable thin films were produced with a concentration of carbon nanostructures up to 8.5%, although the addition of carbon nanostructures in PEGDA decreases the degree of photopolymerization, and PEDGA/carbon nanostructure composites showed electrical conductivity at a relatively low percentage.

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Hsu, Chih-Hung, Jia-Ren Wu, Lung-Chien Chen, Po-Shun Chan, and Cheng-Chiang Chen. "Enhanced Performance of Dye-Sensitized Solar Cells with Nanostructure Graphene Electron Transfer Layer." Advances in Materials Science and Engineering 2014 (2014): 1–4. http://dx.doi.org/10.1155/2014/107352.

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The utilization of nanostructure graphene thin films as electron transfer layer in dye-sensitized solar cells (DSSCs) was demonstrated. The effect of a nanostructure graphene thin film in DSSC structure was examined. The nanostructure graphene thin films provides a great electron transfer channel for the photogenerated electrons from TiO2to indium tin oxide (ITO) glass. Obvious improvements in short-circuit current density of the DSSCs were observed by using the graphene electron transport layer modified photoelectrode. The graphene electron transport layer reduces effectively the back reaction in the interface between the ITO transparent conductive film and the electrolyte in the DSSC.

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Barra, Ana, Cláudia Nunes, Eduardo Ruiz-Hitzky, and Paula Ferreira. "Green Carbon Nanostructures for Functional Composite Materials." International Journal of Molecular Sciences 23, no. 3 (February 6, 2022): 1848. http://dx.doi.org/10.3390/ijms23031848.

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Carbon nanostructures are widely used as fillers to tailor the mechanical, thermal, barrier, and electrical properties of polymeric matrices employed for a wide range of applications. Reduced graphene oxide (rGO), a carbon nanostructure from the graphene derivatives family, has been incorporated in composite materials due to its remarkable electrical conductivity, mechanical strength capacity, and low cost. Graphene oxide (GO) is typically synthesized by the improved Hummers’ method and then chemically reduced to obtain rGO. However, the chemical reduction commonly uses toxic reducing agents, such as hydrazine, being environmentally unfriendly and limiting the final application of composites. Therefore, green chemical reducing agents and synthesis methods of carbon nanostructures should be employed. This paper reviews the state of the art regarding the green chemical reduction of graphene oxide reported in the last 3 years. Moreover, alternative graphitic nanostructures, such as carbons derived from biomass and carbon nanostructures supported on clays, are pointed as eco-friendly and sustainable carbonaceous additives to engineering polymer properties in composites. Finally, the application of these carbon nanostructures in polymer composites is briefly overviewed.

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Wiwatowski, Kamil, Paweł Podlas, Magdalena Twardowska, and Sebastian Maćkowski. "Fluorescence Studies of the Interplay between Metal-Enhanced Fluorescence and Graphene-Induced Quenching." Materials 11, no. 10 (October 9, 2018): 1916. http://dx.doi.org/10.3390/ma11101916.

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Fluorescence microscopy and spectroscopy were applied for studying the optical properties of a hybrid nanostructure, in which we combine plasmon-induced metal enhanced fluorescence with energy transfer to epitaxial graphene. Covering the layer of silver islands with a monolayer graphene, while turning on the efficient energy transfer from emitters, only moderately affects the enhancement of fluorescence attributed to the plasmon resonance in metallic nanostructures—as evidenced by the analysis of fluorescence decays. The results show that it is feasible to combine the properties of graphene with metal-enhanced fluorescence. The importance of the layer thickness of the emitters is also pointed out.

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Roy, Souradeep, Sourav Sain, Shikha Wadhwa, Ashish Mathur, Santosh Dubey, and Susanta S. Roy. "Electrochemical impedimetric analysis of different dimensional (0D–2D) carbon nanomaterials for effective biosensing of L-tyrosine." Measurement Science and Technology 33, no. 1 (October 27, 2021): 014002. http://dx.doi.org/10.1088/1361-6501/ac2cf3.

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Abstract Electrochemical biosensors employing nano-transduction surfaces are considered highly sensitive to the morphology of nanomaterials. Various interfacial parameters namely charge transfer resistance, double layer capacitance, heterogeneous electron transfer rate and diffusion limited processes, depend strongly on the nanostructure geometry which eventually affects the biosensor performance. The present work deals with a comparative study of electrochemical impedance-based detection of L-tyrosine (or simply tyrosine) by employing carbon nanostructures (graphene quantum dots, single walled carbon nanotubes (CNTs) and graphene) along with tyrosinase as the bio-receptor. Specifically, the role of carbon nanostructures (i.e. 0D, 1D and 2D) on charge transfer resistance is investigated by applying time-varying electric field at the nano-bioelectrode followed by calculating the heterogeneous electron transfer rate, double layer capacitor current and their effects on limits of detection and sensitivities towards tyrosine recognition. A theoretical model based on Randel’s equivalent circuit is proposed to account for the redox kinetics at various carbon nanostructure/enzyme hybrid surfaces. It was observed that, the 1D morphology (single walled CNTs) exhibited lowest charge transfer resistance ∼2.62 kΩ (lowest detection limit of 0.61 nM) and highest electron transfer rate ∼0.35 μm s−1 (highest sensitivity 0.37 kΩ nM−1 mm−2). Our results suggest that a suitable morphology of carbon nanostructure would be essential for efficient and sensitive detection of tyrosine.

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Necolau, Mădălina-Ioana, and Andreea-Mădălina Pandele. "Recent Advances in Graphene Oxide-Based Anticorrosive Coatings: An Overview." Coatings 10, no. 12 (November 25, 2020): 1149. http://dx.doi.org/10.3390/coatings10121149.

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The present review outlines the most recent advance in the field of anticorrosive coatings based on graphene oxide nanostructures as active filler. This carbonaceous material was extensively used in the last few years due to its remarkable assets and proved to have a significant contribution to composite materials. Concerning the graphene-based coatings, the synthesis methods, protective function, anticorrosion mechanism, feasible problems, and some methods to improve the overall properties were highlighted. Regarding the contribution of the nanostructure used to improve the capability of the material, several modification strategies for graphene oxide along with the synergistic effect exhibited when functionalized with other compounds were mainly discussed.

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Zeng, B., Z. G. Li, and W. J. Zeng. "N-doped graphene-cadmium sulfide nanoplates and their improved photocatalytic performance." Digest Journal of Nanomaterials and Biostructures 16, no. 2 (2021): 627–33. http://dx.doi.org/10.15251/djnb.2021.162.627.

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Cadmium sulfide nanoplates and N-doped graphene composites (CdS NP/NG) were synthesized for use as photocatalysts. Photocatalytic testing showed that both the two dimensional (2D) nanostructure and nitrogen-doping of graphene contributed to its excellent photocatalytic performance. Here, the 2D nanostructure provided a large number of active sites and the nitrogen-doping of graphene could improve its electronic properties. This work offers a new insight for obtaining a highly efficient CdS/graphene photocatalyst.

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Xu, Yangyang, Jinyang Liu, Chuandong Zuo, Hongbing Cai, Ping Wu, Zhigao Huang, Fachun Lai, Limei Lin, Weifeng Zheng, and Yan Qu. "The Role of Hydrogen on the Growth of Graphene Nanostructure Using a Two-Step Method." Journal of Nanoscience and Nanotechnology 19, no. 11 (November 1, 2019): 7294–300. http://dx.doi.org/10.1166/jnn.2019.16652.

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Chemical vapor deposition (CVD) is widely applied in synthesizing high quality graphene, whose size, shape and structure are strongly impacted by the hydrogen concentration and, however, its role is not fully understood. In the traditional CVD, the concentration of the hydrogen keeps the constant in whole synthesis process and subsequently the nucleation and growth process are carried out simultaneously, therefore, its roles are usually confused and indistinguishable. In this report, the role of hydrogen on the growth of graphene nanostructure was creatively studied by introducing a two-step method which divided the nucleation and growth process for the first time. In the first step, the hexagonal graphene domain grown with the same conditions was used as precursor to eliminate the impact of the nucleation. In the second step, the role of hydrogen on the growth of graphene nanostructure was investigated by controlling the hydrogen concentration. The evolution behavior of the graphene nanostructure with the hydrogen concentration was systematically investigated. Two roles of the hydrogen, namely growth and etching modes, are clearly disclosed and then a possible mechanism was proposed. The results shown here may provide valuable guidance to understand the graphene growth mechanism and further advance the synthesis of unique graphene nanostructure.

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Joseph, J., and Y. C. Lu. "Effect of graphene layer thickness on effective modulus of 3D CNT/Graphene nanostructures." International Journal of Computational Materials Science and Engineering 04, no. 02 (June 2015): 1550010. http://dx.doi.org/10.1142/s2047684115500104.

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Three-dimensional CNT/Graphene nanostructure is consisted of vertically aligned carbon nanotube pillars grown directly on parallel graphene layers. The effect of graphene layer thickness on mechanical properties of the 3D nanostructure is analyzed. Overall, when the graphene layers experience the out-of-plane loading, the effective properties (Young's modulus, shear modulus, and major Poisson's ratio) of the 3D CNT/Graphene structure are significantly dependent upon the thickness of graphene layers. When the graphene layers experience the in-plane loading, the effective properties of the 3D CNT/Graphene structure depend upon the graphene thickness initially and then remain relatively unchanged as the thickness increases. It is found that the optimal performance of the 3D CNT/Graphene structure requires a minimum of thickness for the graphene layers, g/t > 5.

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Sarigamala, Karthik Kiran, Shobha Shukla, Alexander Struck, and Sumit Saxena. "Graphene-Based Coronal Hybrids for Enhanced Energy Storage." Energy Material Advances 2021 (February 20, 2021): 1–15. http://dx.doi.org/10.34133/2021/7273851.

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Functional materials with designer morphologies are anticipated to be the next generation materials for energy storage applications. In this manuscript, we have developed a holistic approach to enhance the surface area and hence the properties of nanostructures by synthesizing coronal nanohybrids of graphene. These nanohybrids provide distinctive advantages in terms of performance and stability over vertically stacked nanocomposites reported in literature. Various double hydroxide materials self-assembled as coronal lamellae on graphene shells have been synthesized and systematically studied. These coronal nanohybrids result in about a threefold increase in energy storage capacity as compared to their traditionally synthesized nanocomposite counterparts. The 3D graphene-based nanofibrils in the synthesized coronal nanohybrids provide mechanical support and connect the nodes of the double hydroxide lattices to inhibit restacking. Complex morphologies such as coronal nanostructures increase the interaction surface of the nanostructure significantly. Such an approach is also expected to bring a paradigm shift in development of functional materials for various applications such as sensors, energy storage, and catalysis.

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Wang, Wei, Xing Wu, and Jian Zhang. "Graphene and Other 2D Material Components Dynamic Characterization and Nanofabrication at Atomic Scale." Journal of Nanomaterials 2015 (2015): 1–6. http://dx.doi.org/10.1155/2015/198126.

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We demonstrate how abreaction corrected transmission electron microscopy (TEM) analysis techniques that are commonly used in nanostructure characterization can be used to study the morphology of graphene and other 2D materials at atomic scale, even subangstrom scale, and evolution of nanostructure and from which we determine the graphene components nanofabrication process. The key contributions of this work are perhaps focused on two areas: (1) recent progress on graphene characterization from the TEM aspect and (2) how the electron beam can be used to fabricate nanoribbon from graphene or similar 2D material.

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Lu, Yang-Ming, Chi-Feng Tseng, Bing-Yi Lan, and Chia-Fen Hsieh. "Fabrication of Graphene/Zinc Oxide Nano-Heterostructure for Hydrogen Sensing." Materials 14, no. 22 (November 17, 2021): 6943. http://dx.doi.org/10.3390/ma14226943.

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In this study, hydrogen (H2) and methane (CH4) were used as reactive gases, and chemical vapor deposition (CVD) was used to grow single-layer graphene on a copper foil substrate. The single-layer graphene obtained was transferred to a single-crystal silicon substrate by PMMA transfer technology for the subsequent growth of nano zinc oxide. The characteristics of CVD-deposited graphene were analyzed by a Raman spectrometer, an optical microscope, a four-point probe, and an ultraviolet/visible spectrometer. The sol–gel method was applied to prepare the zinc oxide seed layer film with the spin-coating method, with methanol, zinc acetate, and sodium hydroxide as the precursors for growing ZnO nanostructures. On top of the ZnO seed layer, a one-dimensional zinc oxide nanostructure was grown by a hydrothermal method at 95 °C, using a zinc nitrate and hexamethylenetetramine mixture solution. The characteristics of the nano zinc oxide were analyzed by scanning electron microscope(SEM),x-ray diffractometer(XRD), and Raman spectrometer. The obtained graphene/zinc oxide nano-heterostructure sensor has a sensitivity of 1.06 at a sensing temperature of 205 °C and a concentration of hydrogen as low as 5 ppm, with excellent sensing repeatability. The main reason for this is that the zinc oxide nanostructure has a large specific surface area, and many oxygen vacancy defects exist on its surface. In addition, the P–N heterojunction formed between the n-type zinc oxide and the p-type graphene also contributes to hydrogen sensing.

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Bai, Xiaoyan, Tianqi Cao, Tianyu Xia, Chenxiao Wu, Menglin Feng, Xinru Li, Ziqing Mei, et al. "MoS2/NiSe2/rGO Multiple-Interfaced Sandwich-like Nanostructures as Efficient Electrocatalysts for Overall Water Splitting." Nanomaterials 13, no. 4 (February 16, 2023): 752. http://dx.doi.org/10.3390/nano13040752.

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Constructing a heterogeneous interface using different components is one of the effective measures to achieve the bifunctionality of nanocatalysts, while synergistic interactions between multiple interfaces can further optimize the performance of single-interface nanocatalysts. The non-precious metal nanocatalysts MoS2/NiSe2/reduced graphene oxide (rGO) bilayer sandwich-like nanostructure with multiple well-defined interfaces is prepared by a simple hydrothermal method. MoS2 and rGO are layered nanostructures with clear boundaries, and the NiSe2 nanoparticles with uniform size are sandwiched between both layered nanostructures. This multiple-interfaced sandwich-like nanostructure is prominent in catalytic water splitting with low overpotential for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) and almost no degradation in performance after a 20 h long-term reaction. In order to simulate the actual overall water splitting process, the prepared nanostructures are assembled into MoS2/NiSe2/rGO||MoS2/NiSe2/rGO modified two-electrode system, whose overpotential is only 1.52 mV, even exceeded that of noble metal nanocatalyst (Pt/C||RuO2~1.63 mV). This work provides a feasible idea for constructing multi-interface bifunctional electrocatalysts using nanoparticle-doped bilayer-like nanostructures.

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Park, Kwang Hyun, Byung Gon Kim, and Sung Ho Song. "Synergistic Effect of a Defect-Free Graphene Nanostructure as an Anode Material for Lithium Ion Batteries." Nanomaterials 10, no. 1 (December 18, 2019): 9. http://dx.doi.org/10.3390/nano10010009.

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Graphene nanosheets have been among the most promising candidates for a high-performance anode material to replace graphite in lithium ion batteries (LIBs). Studies in this area have mainly focused on nanostructured electrodes synthesized by graphene oxide (GO) or reduced graphene oxide (rGO) and surface modifications by a chemical treatment. Herein, we propose a cost-effective and reliable route for generating a defect-free, nanoporous graphene nanostructure (df-GNS) through the sequential insertion of pyridine into a potassium graphite intercalation compound (K-GIC). The as-prepared df-GNS preserves the intrinsic property of graphene without any crystal damage, leading to micro-/nano-porosity (microporosity: ~10–50 µm, nanoporosity: ~2–20 nm) with a significantly large specific surface area. The electrochemical performance of the df-GNS as an anode electrode was assessed and showed a notably enhanced capacity, rate capability, and cycle stability, without fading in capacity or decaying. This is because of the optimal porosity, with perfect preservation of the graphene crystal, allowing faster ion access and a high amount of electron pathways onto the electrode. Therefore, our work will be very helpful for the development of anode and cathode electrodes with higher energy and power performance requirements.

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Kim, Hyun-Kyung, Ali Reza Kamali, Kwang Chul Roh, Kwang-Bum Kim, and Derek John Fray. "Dual coexisting interconnected graphene nanostructures for high performance supercapacitor applications." Energy & Environmental Science 9, no. 7 (2016): 2249–56. http://dx.doi.org/10.1039/c6ee00815a.

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A high-quality hierarchical carbon nanostructure consisting of graphene nanosheets and nanoscrolls can be synthesized by a facile and scalable molten salt method. This carbon nanostructure is here proposed as a high-performance supercapacitor electrode material.

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A A Alhilo, Zaman, Vladimir Pershin, and Aleksey Osipov. "Kinetics of liquid-phase shear exfoliation of graphite in synthetic oils." MATEC Web of Conferences 315 (2020): 06003. http://dx.doi.org/10.1051/matecconf/202031506003.

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Lubricants modified with nanosized particles are of great interest to science and industry, since they have much better tribological characteristics compared to traditional lubricants. One of the most promising nanoparticles is graphene, which has an extremely low coefficient of friction, is very wear-resistant and environmentally friendly. Today, the main problem for the development of a new nano-lubricant is the creation of an environmentally friendly and cheap technology for the industrial production of graphene suspensions or graphene concentrates for the modification of traditional lubricants. The article describes the process of liquid-phase shear exfoliation of graphite in a rotary apparatus with moving blades, in synthetic oils. The kinetic dependences of the exfoliation process, i.e. the dependence of the concentration of graphene nanostructures in suspension over time at different values of the process parameters. It has been experimentally proved that using a stator-rotor mixer with moving blades, it is possible to obtain graphene nanostructure concentrations of at least 2 mg / ml.

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Guo, Quanquan, Yongyue Luo, Jize Liu, Xinxing Zhang, and Canhui Lu. "A well-organized graphene nanostructure for versatile strain-sensing application constructed by a covalently bonded graphene/rubber interface." Journal of Materials Chemistry C 6, no. 8 (2018): 2139–47. http://dx.doi.org/10.1039/c7tc05758j.

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Sethi, Yogesh A., Aniruddha K. Kulkarni, Anuradha A. Ambalkar, Rajendra P. Panmand, Milind V. Kulkarni, Suresh W. Gosavi, and Bharat B. Kale. "Efficient solar light-driven hydrogen generation using an Sn3O4 nanoflake/graphene nanoheterostructure." RSC Advances 11, no. 48 (2021): 29877–86. http://dx.doi.org/10.1039/d1ra05617d.

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Herein, we have demonstrated the synthesis of the two-dimensional hierarchical Sn3O4/graphene nanostructure by a facile solvothermal method. The nanostructure has been used as a photocatalyst for hydrogen production under solar light.

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Trusova, Elena A., Dmitrii D. Titov, Asya M. Afzal, and Sergey S. Abramchuk. "Influence of Graphene Sheets on Compaction and Sintering Properties of Nano-Zirconia Ceramics." Materials 15, no. 20 (October 20, 2022): 7342. http://dx.doi.org/10.3390/ma15207342.

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The use of a nanostructured graphene-zirconia composite will allow the development of new materials with improved performance properties and a high functionality. This work covers a stepwise study related to the creation of a nanostructured composite based on ZrO2 and graphene. A composite was prepared using two suspensions: nano-zirconia obtained by sol-gel synthesis and oxygen-free graphene obtained sonochemically. The morphology of oxygen-free graphene sheets, phase composition and the morphology of a zirconia powder, and the morphology of the synthesized composite were studied. The effect of the graphene sheets on the rheological and sintering properties of a nanostructured zirconia-based composite powder has been studied. It has been found that graphene sheets in a hybrid nanostructure make it difficult to press at the elastic deformation stage, and the composite passes into the plastic region at a lower pressure than a single nano-zirconia. A sintering mechanism was proposed for a composite with a graphene content of 0.635 wt%, in which graphene is an important factor affecting the process mechanism. It has been determined that the activation energy of the composite sintering is more than two times higher than for a single nano-zirconia. Apparently, due to the van der Waals interaction, the graphene sheets partially stabilize the zirconia and prevent the disordering of the surface monolayers of its nanocrystals and premelting prior to the sintering. This leads to an increase in the activation energy of the composite sintering, and its sintering occurs, according to a mixed mechanism, in which the grain boundary diffusion predominates, in contrast to the single nano-zirconia sintering, which occurs through a viscous flow.

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Saji, Viswanathan S. "Carbon nanostructure-based superhydrophobic surfaces and coatings." Nanotechnology Reviews 10, no. 1 (January 1, 2021): 518–71. http://dx.doi.org/10.1515/ntrev-2021-0039.

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Abstract Research and development on superhydrophobic carbon nanostructures and their nanocomposites have high industrial significance. Here, a comprehensive review of the topic is provided. Reported works on superhydrophobic surfaces and coatings of carbon nanotubes, nanofibres, nanospheres/nanothorns/others, nanodiamond, fullerene and their various nanocomposites with metals, ceramics, and polymers are described. Superhydrophobic nanostructured carbon soot, graphitic carbon, and others are also presented. The section on superhydrophobic graphene is presented concisely at the end. Reports in different application areas, including anti-corrosion, anti-icing, oil separation, anti-biofouling, and sensors, are discussed separately. Superoleophobic and superamphiphobic surfaces are also discussed.

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Oliveira, Pâmella Schramm, Aline Rossato, Larissa da Silva Silveira, Cristian Mafra Ledur, Walter Paixão de Sousa Filho, Claudir Gabriel Kaufmann Junior, Sergio Roberto Mortari, et al. "GRAPHENE OXIDE AND REDUCED GRAPHENE OXIDE." International Journal for Innovation Education and Research 9, no. 12 (December 1, 2021): 142–69. http://dx.doi.org/10.31686/ijier.vol9.iss12.3572.

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To present a possible new alternative for wound treatment, this work evaluated the biological safety and therapeutic efficacy of graphene oxide (GO) and reduced graphene oxide (rGO) nanoparticles (NPs). First, the nanostructures were studied in silico and showed to be able to inhibit the production of some pro-inflammatory cytokines and stimulate the production of the anti-inflammatory cytokine IL-10, especially rGO. The results of the morphological and structural characterization of GO NPs synthesized from the Hummers method and reduced by ascorbic acid, were consistent with the literature, confirming their achievement. In the broth microdilution assay, GO and rGO showed antimicrobial activity against the clinical isolate of Streptococcus agalactiae (S. agalactiae) at a minimum inhibitory concentration (MIC) of 625 µg/mL for GO and 312.5 µg/mL for rGO. In addition, the nanostructure of rGO was able to inhibit, in subinhibitory concentration, the formation of S. agalactiae biofilm by up to 77% when compared to the positive control. Both NPs, in all tested concentrations, did not cause hemolysis, and alterations in coagulation in vitro assays. However, in the safety tests, it was evidenced that only the MIC of 312, µg/mL for rGO was biologically safe and presented anti-inflammatory and healing behavior in vitro. In general, the present work confirmed rGO's potential in the treatment of chronic wounds, since in silico showed anti-inflammatory behavior and in vitro showed therapeutic efficacy at low concentrations, prevented biofilm formation, and showed no significant toxic effects.

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Sharma, Monika, Jue-Hyuk Jang, Dong Yun Shin, Jeong An Kwon, Dong-Hee Lim, Daeil Choi, Hukwang Sung, et al. "Work function-tailored graphene via transition metal encapsulation as a highly active and durable catalyst for the oxygen reduction reaction." Energy & Environmental Science 12, no. 7 (2019): 2200–2211. http://dx.doi.org/10.1039/c9ee00381a.

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Athithya, Seenidurai, Valparai Surangani Manikandan, Santhana Krishnan Harish, Kuppusamy Silambarasan, Shanmugam Gopalakrishnan, Hiroya Ikeda, Mani Navaneethan, and Jayaram Archana. "Plasmon Effect of Ag Nanoparticles on TiO2/rGO Nanostructures for Enhanced Energy Harvesting and Environmental Remediation." Nanomaterials 13, no. 1 (December 23, 2022): 65. http://dx.doi.org/10.3390/nano13010065.

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We report Ag nanoparticles infused with mesosphere TiO2/reduced graphene oxide (rGO) nanosheet (TiO2/rGO/Ag) hybrid nanostructures have been successfully fabricated using a series of solution process synthesis routes and an in-situ growth method. The prepared hybrid nanostructure is utilized for the fabrication of photovoltaic cells and the photocatalytic degradation of pollutants. The photovoltaic characteristics of a dye-sensitized solar cell (DSSC) device with plasmonic hybrid nanostructure (TiO2/rGO/Ag) photoanode achieved a highest short-circuit current density (JSC) of 16.05 mA/cm2, an open circuit voltage (VOC) of 0.74 V and a fill factor (FF) of 62.5%. The fabricated plasmonic DSSC device exhibited a maximum power conversion efficiency (PCE) of 7.27%, which is almost 1.7 times higher than the TiO2-based DSSC (4.10%). For the photocatalytic degradation of pollutants, the prepared TiO2/rGO/Ag photocatalyst exhibited superior photodegradation of methylene blue (MB) dye molecules at around 93% and the mineralization of total organic compounds (TOC) by 80% in aqueous solution after 160 min under continuous irradiation with natural sunlight. Moreover, the enhanced performance of the DSSC device and the MB dye degradation exhibited by the hybrid nanostructures are more associated with their high surface area. Therefore, the proposed plasmonic hybrid nanostructure system is a further development for photovoltaics and environmental remediation applications.

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Galstyan, Vardan, Elisabetta Comini, Iskandar Kholmanov, Andrea Ponzoni, Veronica Sberveglieri, Nicola Poli, Guido Faglia, and Giorgio Sberveglieri. "A composite structure based on reduced graphene oxide and metal oxide nanomaterials for chemical sensors." Beilstein Journal of Nanotechnology 7 (October 10, 2016): 1421–27. http://dx.doi.org/10.3762/bjnano.7.133.

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A hybrid nanostructure based on reduced graphene oxide and ZnO has been obtained for the detection of volatile organic compounds. The sensing properties of the hybrid structure have been studied for different concentrations of ethanol and acetone. The response of the hybrid material is significantly higher compared to pristine ZnO nanostructures. The obtained results have shown that the nanohybrid is a promising structure for the monitoring of environmental pollutants and for the application of breath tests in assessment of exposure to volatile organic compounds.

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Chen, Hsin-Yu, Yi-Hong Xiao, Lin-Jiun Chen, Chi-Ang Tseng, and Chuan-Pei Lee. "Low-Dimensional Nanostructures for Electrochemical Energy Applications." Physics 2, no. 3 (September 11, 2020): 481–502. http://dx.doi.org/10.3390/physics2030027.

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Materials with different nanostructures can have diverse physical properties, and they exhibit unusual properties as compared to their bulk counterparts. Therefore, the structural control of desired nanomaterials is intensely attractive to many scientific applications. In this brief review, we mainly focus on reviewing our recent reports based on the materials of graphene and the transition metal chalcogenide, which have various low-dimensional nanostructures, in relation to the use of electrocatalysts in electrochemical energy applications; moreover, related literatures were also partially selected for discussion. In addition, future aspects of the nanostructure design related to the further enhancement of the performance of pertinent electrochemical energy devices will also be mentioned.

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Li, Dayu, Yuling Lu, and Chao Zhang. "Superhydrophobic and Electrochemical Performance of CF2-Modified g-C3N4/Graphene Composite Film Deposited by PECVD." Nanomaterials 12, no. 24 (December 9, 2022): 4387. http://dx.doi.org/10.3390/nano12244387.

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The physicochemical properties of functional graphene are regulated by compositing with other nano-carbon materials or modifying functional groups on the surface through plasma processes. The functional graphene films with g-C3N4 and F-doped groups were produced by controlling the deposition steps and plasma gases via radio frequency plasma-enhanced chemical vapor deposition (RF-PECVD). The first principles calculation and electrochemistry characteristic of the functional graphene films were performed on Materials Studio software and an electrochemical workstation, respectively. It is found that the nanostructures of functional graphene films with g-C3N4 and F-doped groups were significantly transformed. The introduction of fluorine atoms led to severe deformation of the g-C3N4 nanostructure, which created gaps in the electrostatic potential of the graphene surface and provided channels for electron transport. The surface of the roving fabric substrate covered by pure graphene is hydrophilic with a static contact angle of 79.4°, but the surface is transformed to a hydrophobic state for the g-C3N4/graphene film with an increased static contact angle of 131.3° which is further improved to 156.2° for CF2-modified g-C3N4/graphene film exhibiting the stable superhydrophobic property. The resistance of the electron movement of CF2-modified g-C3N4/graphene film was reduced by 2% and 76.7%, respectively, compared with graphene and g-C3N4/graphene.

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Rozel, Petr, Darya Radziuk, Lubov Mikhnavets, Evgenij Khokhlov, Vladimir Shiripov, Iva Matolínová, Vladimír Matolín, Alexander Basaev, Nikolay Kargin, and Vladimir Labunov. "Properties of Nitrogen/Silicon Doped Vertically Oriented Graphene Produced by ICP CVD Roll-to-Roll Technology." Coatings 9, no. 1 (January 19, 2019): 60. http://dx.doi.org/10.3390/coatings9010060.

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Simultaneous mass production of high quality vertically oriented graphene nanostructures and doping them by using an inductively coupled plasma chemical vapor deposition (ICP CVD) is a technological problem because little is understood about their growth mechanism over enlarged surfaces. We introduce a new method that combines the ICP CVD with roll-to-roll technology to enable the in-situ preparation of vertically oriented graphene by using propane as a precursor gas and nitrogen or silicon as dopants. This new technology enables preparation of vertically oriented graphene with distinct morphology and composition on a moving copper foil substrate at a lower cost. The technological parameters such as deposition time (1–30 min), gas partial pressure, composition of the gas mixture (propane, argon, nitrogen or silane), heating treatment (1–60 min) and temperature (350–500 °C) were varied to reveal the nanostructure growth, the evolution of its morphology and heteroatom’s intercalation by nitrogen or silicon. Unique nanostructures were examined by FE-SEM microscopy, Raman spectroscopy and energy dispersive X-Ray scattering techniques. The undoped and nitrogen- or silicon-doped nanostructures can be prepared with the full area coverage of the copper substrate on industrially manufactured surface defects. Longer deposition time (30 min, 450 °C) causes carbon amorphization and an increased fraction of sp3-hybridized carbon, leading to enlargement of vertically oriented carbonaceous nanostructures and growth of pillars.

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Gerasimenko, Alexander Yu, Artem V. Kuksin, Yury P. Shaman, Evgeny P. Kitsyuk, Yulia O. Fedorova, Denis T. Murashko, Artemiy A. Shamanaev, et al. "Hybrid Carbon Nanotubes–Graphene Nanostructures: Modeling, Formation, Characterization." Nanomaterials 12, no. 16 (August 16, 2022): 2812. http://dx.doi.org/10.3390/nano12162812.

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A technology for the formation and bonding with a substrate of hybrid carbon nanostructures from single-walled carbon nanotubes (SWCNT) and reduced graphene oxide (rGO) by laser radiation is proposed. Molecular dynamics modeling by the real-time time-dependent density functional tight-binding (TD-DFTB) method made it possible to reveal the mechanism of field emission centers formation in carbon nanostructures layers. Laser radiation stimulates the formation of graphene-nanotube covalent contacts and also induces a dipole moment of hybrid nanostructures, which ensures their orientation along the force lines of the radiation field. The main mechanical and emission characteristics of the formed hybrid nanostructures were determined. By Raman spectroscopy, the effect of laser radiation energy on the defectiveness of all types of layers formed from nanostructures was determined. Laser exposure increased the hardness of all samples more than twice. Maximum hardness was obtained for hybrid nanostructure with a buffer layer (bl) of rGO and the main layer of SWCNT—rGO(bl)-SWCNT and was 54.4 GPa. In addition, the adhesion of rGO to the substrate and electron transport between the substrate and rGO(bl)-SWCNT increased. The rGO(bl)-SWCNT cathode with an area of ~1 mm2 showed a field emission current density of 562 mA/cm2 and stability for 9 h at a current of 1 mA. The developed technology for the formation of hybrid nanostructures can be used both to create high-performance and stable field emission cathodes and in other applications where nanomaterials coating with good adhesion, strength, and electrical conductivity is required.

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Rahimi Mamaghani, Kaveh, Seyed Morteza Naghib, Alireza Zahedi, Amir Hossein Zeinali Kalkhoran, and Mehdi Rahmanian. "Fast synthesis of methacrylated graphene oxide: a graphene‐functionalised nanostructure." Micro & Nano Letters 13, no. 2 (February 2018): 195–97. http://dx.doi.org/10.1049/mnl.2017.0461.

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Ozawa, Hiroaki, and Masa-aki Haga. "Soft nano-wrapping on graphene oxide by using metal–organic network films composed of tannic acid and Fe ions." Physical Chemistry Chemical Physics 17, no. 14 (2015): 8609–13. http://dx.doi.org/10.1039/c5cp00264h.

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Graphene oxide nanosheets were easily covered with uniform metal–organic network films composed of tannic acid and Fe ions. The graphene oxide in the composite sheets was reduced chemically without the collapse of the wrapped nanostructure.

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Zhang, Hongfen, Baiyan Zhang, Anjia Chen, and Yong Qin. "Controllable n-Fe2O3@graphene nanomaterials by ALD applied in an aptasensor with enhanced electrochemical performance for thrombin detection." Dalton Transactions 46, no. 23 (2017): 7434–40. http://dx.doi.org/10.1039/c7dt01184a.

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An elegant atomic layer deposition (ALD) method has been employed for the controllable preparation of a uniform Fe₂O₃-coated graphene nanostructure (Fe₂O₃@graphene).

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Zhou, Hengjie, Shaojian Su, Weibin Qiu, Zeyang Zhao, Zhili Lin, Pingping Qiu, and Qiang Kan. "Multiple Fano Resonances with Tunable Electromagnetic Properties in Graphene Plasmonic Metamolecules." Nanomaterials 10, no. 2 (January 29, 2020): 236. http://dx.doi.org/10.3390/nano10020236.

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Multiple Fano resonances (FRs) can be produced by destroying the symmetry of structure or adding additional nanoparticles without changing the spatial symmetry, which has been proved in noble metal structures. However, due to the disadvantages of low modulation depth, large damping rate, and broadband spectral responses, many resonance applications are limited. In this research paper, we propose a graphene plasmonic metamolecule (PMM) by adding an additional 12 nanodiscs around a graphene heptamer, where two Fano resonance modes with different wavelengths are observed in the extinction spectrum. The competition between the two FRs as well as the modulation depth of each FR is investigated by varying the materials and the geometrical parameters of the nanostructure. A simple trimer model, which emulates the radical distribution of the PMM, is employed to understand the electromagnetic field behaviors during the variation of the parameters. Our proposed graphene nanostructures might find significant applications in the fields of single molecule detection, chemical or biochemical sensing, and nanoantenna.

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Razzaq, Abdul, and Su-Il In. "TiO2 Based Nanostructures for Photocatalytic CO2 Conversion to Valuable Chemicals." Micromachines 10, no. 5 (May 15, 2019): 326. http://dx.doi.org/10.3390/mi10050326.

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Photocatalytic conversion of CO2 to useful products is an alluring approach for acquiring the two-fold benefits of normalizing excess atmospheric CO2 levels and the production of solar chemicals/fuels. Therefore, photocatalytic materials are continuously being developed with enhanced performance in accordance with their respective domains. In recent years, nanostructured photocatalysts such as one dimensional (1-D), two dimensional (2-D) and three dimensional (3-D)/hierarchical have been a subject of great importance because of their explicit advantages over 0-D photocatalysts, including high surface areas, effective charge separation, directional charge transport, and light trapping/scattering effects. Furthermore, the strategy of doping (metals and non-metals), as well as coupling with a secondary material (noble metals, another semiconductor material, graphene, etc.), of nanostructured photocatalysts has resulted in an amplified photocatalytic performance. In the present review article, various titanium dioxide (TiO2)-based nanostructured photocatalysts are briefly overviewed with respect to their application in photocatalytic CO2 conversion to value-added chemicals. This review primarily focuses on the latest developments in TiO2-based nanostructures, specifically 1-D (TiO2 nanotubes, nanorods, nanowires, nanobelts etc.) and 2-D (TiO2 nanosheets, nanolayers), and the reaction conditions and analysis of key parameters and their role in the up-grading and augmentation of photocatalytic performance. Moreover, TiO2-based 3-D and/or hierarchical nanostructures for CO2 conversions are also briefly scrutinized, as they exhibit excellent performance based on the special nanostructure framework, and can be an exemplary photocatalyst architecture demonstrating an admirable performance in the near future.

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SASAKI, Ryo, and Kazuhito SHINTANI. "Indentation simulation of a pillared-graphene nanostructure." Proceedings of Mechanical Engineering Congress, Japan 2016 (2016): G0300505. http://dx.doi.org/10.1299/jsmemecj.2016.g0300505.

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Zhang Hui-Zhen, Li Jin-Tao, L Wen-Gang, Yang Hai-Fang, Tang Cheng-Chun, Gu Chang-Zhi, and Li Jun-Jie. "Fabrication of graphene nanostructure and bandgap tuning." Acta Physica Sinica 66, no. 21 (2017): 217301. http://dx.doi.org/10.7498/aps.66.217301.

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Dienel, Thomas, Shigeki Kawai, Hajo Söde, Xinliang Feng, Klaus Müllen, Pascal Ruffieux, Roman Fasel, and Oliver Gröning. "Resolving Atomic Connectivity in Graphene Nanostructure Junctions." Nano Letters 15, no. 8 (July 20, 2015): 5185–90. http://dx.doi.org/10.1021/acs.nanolett.5b01403.

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Zhang, Qingtian, and Kwok Sum Chan. "Pure valley current generation in graphene nanostructure." Physics Letters A 386 (January 2021): 126990. http://dx.doi.org/10.1016/j.physleta.2020.126990.

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Cho, Hak Dong, Deuk Young Kim, and Jong-Kwon Lee. "ZnO Nanorod/Graphene Hybrid-Structures Formed on Cu Sheet by Self-Catalyzed Vapor-Phase Transport Synthesis." Nanomaterials 11, no. 2 (February 10, 2021): 450. http://dx.doi.org/10.3390/nano11020450.

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High crystalline ZnO nanorods (NRs) on Zn pre-deposited graphene/Cu sheet without graphene transfer process have been fabricated by self-catalyzed vapor-phase transport synthesis. Here, the pre-deposited Zn metal on graphene not only serves as a seed to grow the ZnO NRs, but also passivates the graphene underneath. The temperature-dependent photoluminescence spectra of the fabricated ZnO NRs reveal a dominant peak of 3.88 eV at 10 K associated with the neutral-donor bound exciton, while the redshifted peak by bandgap shrinkage with temperature and electron-lattice interactions leads a strong emission at 382 nm at room temperature. The optical absorption of the ZnO NRs/graphene hetero-nanostructure at this ultraviolet (UV) emission is then theoretically analyzed to quantify the absorption amount depending on the ZnO NR distribution. By simply covering the ZnO NR/graphene/Cu structure with the graphene/glass as a top electrode, it is observed that the current-voltage characteristic of the ZnO NR/graphene hetero-nanojunction device exhibits a photocurrent of 1.03 mA at 3 V under a light illumination of 100 μW/cm2. In particular, the suggested graphene/ZnO NRs/graphene hybrid-nanostructure-based devices reveal comparable photocurrents at a bidirectional bias, which can be a promising platform to integrate 1D and 2D nanomaterials without complex patterning process for UV device applications.

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Ibrahim Alabid, Khalil, and Hajar Nasser. "Synthesis and Characterization Graphene- Carbon Nitride Nanostructure in One Step." Ibn AL-Haitham Journal For Pure and Applied Sciences 36, no. 3 (July 20, 2023): 260–72. http://dx.doi.org/10.30526/36.3.3103.

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Graphene-carbon nitride can be synthesized from thiourea in a single step at a temperature of four hours at a rate of 2.3 ℃/min. Graphene-carbon nitride was characterized by Fourier-transform infrared spectroscopy (FTIR), energy dispersive X-ray analysis (EDX), scanning electron microscopy, and spectrophotometry (UV-VIS). Graphene-carbon nitride was found to consist of triazine and heptazine structures, carbon, and nitrogen. The weight percentage of carbon and the atomic percentage of carbon are 40.08%, and the weight percentage of nitrogen and the atomic percentage of nitrogen are 40.08%. Therefore, the ratio and the dimensions of the graphene-carbon nitride were characterized by scanning electron microscopy, and it was found that the radius was within the range of (2 µm-147.1 nm). In addition, it was found that it absorbed light in the visible field (VIS). The objective of the manufacture and characterization of graphene-carbon nitride for use in the manufacture of a selective electrode for an organic pollutant (currently used in the manufacture of a selective electrode for the analysis of organic dye).

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Alharbi, Raed, and Mustafa Yavuz. "Promote Localized Surface Plasmonic Sensor Performance via Spin-Coating Graphene Flakes over Au Nano-Disk Array." Photonics 6, no. 2 (May 25, 2019): 57. http://dx.doi.org/10.3390/photonics6020057.

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Although localized surface plasmonic resonance (LSPR) sensors have advantages over regular surface plasmonic resonance (SPR) sensors, such as in sensor setup, excitation method, and cost, they suffer from low performance when compared to SPR sensors, which thus limits their commercialization. Among different methods applied to promote LSPR sensor performance, metal-two-dimensional (2D) hybrid nanostructure has been shown to be an efficient improvement. However, metal-2D hybrid nanostructures may come in a complex or a simple scheme and the latter is preferred to avoid challenges in fabrication work and to be applicable in mass production. In this work, a new and simple gold-graphene hybrid scheme is proposed and its plasmonic sensing performance is numerically evaluated using the finite different time domain (FDTD) method. The proposed sensor can be fabricated by growing a Au nano-disk (ND) array on a quartz substrate and then spin-coating graphene flakes of different sizes and shapes randomly on top of and between the Au NDs. Very high sensitivity value is achieved with 2262 nm/RIU at a 0.01 refractive index change. The obtained sensitivity value is very competitive in the field of LSPR sensors using metal-2D hybrid nanostructure. This proposed sensor can be utilized in different biosensing applications such as immunosensors, sensing DNA hybridization, and early disease detection, as discussed at the end of this article.

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Farmani, Homa, and Ali Farmani. "Graphene sensing nanostructure for exact graphene layers identification at terahertz frequency." Physica E: Low-dimensional Systems and Nanostructures 124 (October 2020): 114375. http://dx.doi.org/10.1016/j.physe.2020.114375.

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Journal articles on the topic 'Nanostructure - Graphene'

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