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《Advanced Materials Technologies》2018,3(4)
Laser reduction of graphene oxide has attracted significant interest in recent years, because it offers a highly flexible, rapid, and chemical‐free graphene fabrication route that can directly write on almost any solid substrate with down to sub‐micrometer feature size. Laser‐reduced graphene (LRG) is explored for various important applications such as supercapacitors, sensors, field effect transistors, holograms, solar cells, flat lenses, bolometers, thermal sound sources, cancer treatment, water purification, lithium‐ion batteries, and electrothermal heaters. This contribution reviews most recent research progress on the aspects of fabrication, properties, and applications of LRG. Particular attention is paid to the mechanism of LRG formation, which is still debatable. The three main theories, including the photochemical process, the photothermal process, and a combination of both processes, are discussed. Strategies for tuning the properties and performance of LRG, such as the laser parameters, chemical doping, structure modulation, and environment control, are highlighted. LRGs with better performance including smaller feature size, higher conductivity, and more flexible morphology design in both 2D and 3D formats will offer tremendous opportunities for advancement in electronics, photonic, and optoelectronic applications. 相似文献
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Isolated graphene, a nanometer‐thick two‐dimensional analog of fullerenes and carbon nanotubes, has recently sparked great excitement in the scientific community given its excellent mechanical and electronic properties. Particularly attractive is the availability of bulk quantities of graphene as both colloidal dispersions and powders, which enables the facile fabrication of many carbon‐based materials. The fact that such large amounts of graphene are most easily produced via the reduction of graphene oxide—oxygenated graphene sheets covered with epoxy, hydroxyl, and carboxyl groups—offers tremendous opportunities for access to functionalized graphene‐based materials. Both graphene oxide and graphene can be processed into a wide variety of novel materials with distinctly different morphological features, where the carbonaceous nanosheets can serve as either the sole component, as in papers and thin films, or as fillers in polymer and/or inorganic nanocomposites. This Review summarizes techniques for preparing such advanced materials via stable graphene oxide, highly reduced graphene oxide, and graphene dispersions in aqueous and organic media. The excellent mechanical and electronic properties of the resulting materials are highlighted with a forward outlook on their applications. 相似文献
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Konrad Trzci&#x;ski Raul D. Rodriguez Constance Schmidt Mahfujur Rahaman Miros&#x;aw Sawczak Anna Lisowska‐Oleksiak Jacek Gasiorowski Dietrich R. T. Zahn 《Advanced Materials Interfaces》2016,3(4)
Relatively high temperatures even up to 500 °C are required to obtain bismuth vanadate (BiVO4) films with the scheelite monoclinic (s‐m) structure that shows the highest photocatalytic activity. This requirement limits the possible choice of substrates. Moreover, high quality thin layers of crystalline BiVO4 cannot be prepared with current methods. In this study a light‐induced crystallization approach is presented, which is a step toward preparation and patterning of BiVO4 (s‐m) films for applications on plastic substrates. Thin films of amorphous BiVO4 are prepared by pulsed laser deposition. The possibility of using green (514.7 nm) laser illumination for crystallization of BiVO4 is investigated. The laser‐induced phase transition is tracked using Raman spectroscopy. The results are compared with those obtained from thermally annealed samples, crystalline structure of which is confirmed by measuring X‐ray diffraction. The homogeneity and quality of crystallization are verified using micro‐Raman spectroscopy imaging, while time‐dependent experiments reveal the crystallization rate. The conductivity of the crystallized region is investigated using conductive atomic force microscopy. A strong increase in the conductivity is found in the patterned regions. Experimental results demonstrate the possibility of using the laser‐induced crystallization of BiVO4 to prepare patterns of improved conductivity and semiconducting properties in comparison to amorphous surroundings. 相似文献
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Peigen Cao Peter Bai Arash A. Omrani Yihan Xiao Kacey L. Meaker Hsin‐Zon Tsai Aiming Yan Han Sae Jung Ramin Khajeh Griffin F. Rodgers Youngkyou Kim Andrew S. Aikawa Mattew A. Kolaczkowski Yi Liu Alex Zettl Ke Xu Michael F. Crommie Ting Xu 《Advanced materials (Deerfield Beach, Fla.)》2017,29(36)
A monolayer 2D capping layer with high Young's modulus is shown to be able to effectively suppress the dewetting of underlying thin films of small organic semiconductor molecule, polymer, and polycrystalline metal, respectively. To verify the universality of this capping layer approach, the dewetting experiments are performed for single‐layer graphene transferred onto polystyrene (PS), semiconducting thienoazacoronene (EH‐TAC), gold, and also MoS2 on PS. Thermodynamic modeling indicates that the exceptionally high Young's modulus and surface conformity of 2D capping layers such as graphene and MoS2 substantially suppress surface fluctuations and thus dewetting. As long as the uncovered area is smaller than the fluctuation wavelength of the thin film in a dewetting process via spinodal decomposition, the dewetting should be suppressed. The 2D monolayer‐capping approach opens up exciting new possibilities to enhance the thermal stability and expands the processing parameters for thin film materials without significantly altering their physical properties. 相似文献
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Stanislav A. Evlashin Sergey E. Svyakhovskiy Fedor S. Fedorov Yuri A. Mankelevich Pavel V. Dyakonov Nikita V. Minaev Sarkis A. Dagesyan Konstantin I. Maslakov Roman A. Khmelnitsky Nikolay V. Suetin Iskander S. Akhatov Albert G. Nasibulin 《Advanced Materials Interfaces》2018,5(18)
Reduced graphene oxide (GO) becomes one of the most popular materials for applications in various optical, electronic, and sensor devices. Even though many methods are already reported for reduced graphene oxide synthesis, they usually raise issues related to their efficiency, quality, and environmental impact. This work demonstrates a simple, environmental friendly, and effective method for reducing graphene oxide under ambient conditions using nanosecond infrared laser irradiation. As a result, a Raman band intensity ratio of I(G)/I(D) of 4.59 is achieved with an average crystallite size of ≈90 nm. This graphene is of higher quality than what can be achieved with most of the existing methods. Additionally, the demonstrated reduction technique allows the selective reduction of graphene oxide and control the amount of functional groups on the surface of the material. Gas sensors fabricated according to the proposed technique efficiently detect NO2, NH3, and H2S with the sensitivity down to 10 ppm. 相似文献
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Tang LA Lee WC Shi H Wong EY Sadovoy A Gorelik S Hobley J Lim CT Loh KP 《Small (Weinheim an der Bergstrasse, Germany)》2012,8(3):423-431
Inspired by the amphiphilicity of graphene oxide (GO), the surface of water is used as a template for the assembly of a GO film. Methacrylate-functionalized GO sheets can be cross-linked instantaneously at the water-air interface to form a highly wrinkled membrane spreading over an extended area. The multiple covalent linkages amongst the GO sheets enhances the in-plane stiffness of the film compared to noncovalently bonded GO films. The highly convoluted GO membrane can be used in two applications: the promoting of spontaneous stem-cell differentiation towards bone cell lineage without any chemical inducers, and for supercapacitor electrodes. Due to reduced van der Waals restacking, capacitance values up to 211 F g(-1) can be obtained. The scalable and inexpensive nature of this assembly route enables the engineering of membranes for applications in regenerative medicine and energy-storage devices where secondary structures like nanotopography and porosity are important performance enhancers. 相似文献
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《Advanced Materials Technologies》2018,3(4)
Scalable and routine integration of chemically exfoliated, graphene‐based materials such as graphene oxide (GO) and reduced graphene oxide (rGO) into standard microelectronic fabrication is a tremendous technological challenge, blocking their advancement toward real applications. A unique approach for wafer‐scale fabrication of rGO devices by a synergistic combination of chemically exfoliated GO with photolithography processing is realized. Using graphite powder as source material, a GO solution is produced in a newly optimized, low‐temperature exfoliation and desalination protocol, resulting in high‐quality GO and confirmed by various characterization techniques. As substrates, 4 in. Si/SiO2 or glass wafers were first silanized in a well‐controlled, gas‐phase procedure. Large‐area GO thin films are then realized by standard spin‐coating resulting in highly homogeneous, covalently bound layers of controllable thicknesses of 3–7 nm depending on the amount of spin‐coatings. The robust thin films undergo routine photolithography for device fabrication, including reduction via thermal annealing into conductive rGO. The top‐down fabricated rGO devices display high uniformity with electrical resistances varying within only one order of magnitude over wafer‐scale and device yields as high as ≈93% on a wafer. The novel front‐end‐of‐line GO integration protocol offers robust electrical performances for future implementation toward various sensor applications. 相似文献
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Jibo Zhang Muqing Ren Luqing Wang Yilun Li Boris I. Yakobson James M. Tour 《Advanced materials (Deerfield Beach, Fla.)》2018,30(21)
An efficient metal‐free catalyst is presented for oxygen evolution and reduction based on oxidized laser‐induced graphene (LIG‐O). The oxidation of LIG by O2 plasma to form LIG‐O boosts its performance in the oxygen evolution reaction (OER), exhibiting a low onset potential of 260 mV with a low Tafel slope of 49 mV dec?1, as well as an increased activity for the oxygen reduction reaction. Additionally, LIG‐O shows unexpectedly high activity in catalyzing Li2O2 decomposition in Li‐O2 batteries. The overpotential upon charging is decreased from 1.01 V in LIG to 0.63 V in LIG‐O. The oxygen‐containing groups make essential contributions, not only by providing the active sites, but also by facilitating the adsorption of OER intermediates and lowering the activation energy. 相似文献
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化学还原石墨烯薄膜的制备及结构表征 总被引：1，自引：1，他引：0
以天然鳞片石墨为原材料,采用Hummers法成功制备了氧化石墨,并采用化学还原方法制备石墨烯薄膜材料,分别应用X射线衍射(XRD)、能谱分析(EDS)、拉曼光谱分析(Raman)、傅里叶变换红外光谱(FTIR)和扫描电镜(SEM)对氧化石墨和化学还原石墨烯薄膜的性能、结构和形貌进行了表征。实验结果表明,通过控制溶液的pH值为10可防止石墨烯团聚,石墨烯溶液的分散性非常好,碳氧比达到了8.8∶1,扫描电镜图片观察到了较薄的片层。通过XRD图谱可以看出,石墨烯薄膜比原始石墨的层间距变大。拉曼光谱表明,石墨烯薄膜相对氧化石墨的ID/IG值更大,样品在还原的过程中无序度增加。石墨烯薄膜的微观结构研究为其在超级电容器电极或重金属废水过滤膜等方面的应用提供了理论基础。 相似文献
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Changbao Zhu Peter Kopold Peter A. van Aken Joachim Maier Yan Yu 《Advanced materials (Deerfield Beach, Fla.)》2016,28(12):2409-2416
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Shuchao Wang Ali K. Yetisen Martin Jakobi Quan Zhou Alexander W. Koch 《Advanced Engineering Materials》2023,25(19):2300962
This article presents nanoscale-thick and large-area graphene oxide (GO) films manufactured by a facile method to enable high-performance sound detection in liquids. A Fabry–Perot (F–P) cavity consisting of a GO film, whose vibration diameter is ≈4.4 mm, and a single-mode fiber (SMF) is used as the sensing core for sound detection in liquids. A sound-transparent cap, consisting of a support sleeve and a sound-transparent sleeve, is used to protect the GO-sensing diaphragm to resist liquid pressure to enable long-term stability. The sensing probes with GO diaphragms of ≈100 and 200 nm thickness are placed in ultra-pure water for performance testing. Test results show that they maintain a linear sound pressure response, a flat frequency response, and a uniform directional response from 1 to 100 kHz. They have sensitivities of ≈630 mV Pa−1 and about 84 mV Pa−1, respectively, in the range of 1–100 kHz in all directions in different liquids. These results demonstrate the suitability of the nanoscale-thick and large-area GO films for sound detection in liquids with high performance. 相似文献
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Jie Wang Minghui Liang Yan Fang Tengfei Qiu Jin Zhang Linjie Zhi 《Advanced materials (Deerfield Beach, Fla.)》2012,24(21):2874-2878
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Jianfeng Wang Chao Teng Ying Jiang Ying Zhu Lei Jiang 《Advanced materials (Deerfield Beach, Fla.)》2019,31(10)
Owing to inherent 2D structure, marvelous mechanical, electrical, and thermal properties, graphene has great potential as a macroscopic thin film for surface coating, composite, flexible electrode, and sensor. Nevertheless, the production of large‐area graphene‐based thin film from pristine graphene dispersion is severely impeded by its poor solution processability. In this study, a robust wetting‐induced climbing strategy is reported for transferring the interfacially assembled large‐area ultrathin pristine graphene film. This strategy can quickly convert solvent‐exfoliated pristine graphene dispersion into ultrathin graphene film on various substrates with different materials (glass, metal, plastics, and cloth), shapes (film, fiber, and bulk), and hydrophobic/hydrophilic patterns. It is also applicable to nanoparticles, nanofibers, and other exfoliated 2D nanomaterials for fabricating large‐area ultrathin films. Alternate climbing of different ultrathin nanomaterial films allows a layer‐by‐layer transfer, forming a well‐ordered layered composite film with the integration of multiple pristine nanomaterials at nanometer scale. This powerful strategy would greatly promote the development of solvent‐exfoliated pristine nanomaterials from dispersions to macroscopic thin film materials. 相似文献
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Miao Zhang Liang Huang Ji Chen Chun Li Gaoquan Shi 《Advanced materials (Deerfield Beach, Fla.)》2014,26(45):7588-7592
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AFM surface analysis of ZnO layers prepared by pulsed laser deposition at different oxygen pressures
Polycrystalline thin films of zinc oxide were deposited by pulsed laser deposition onto silicon substrates at different oxygen partial pressures in the range of 1-35 Pa. For ablation of the sintered zinc oxide target a pulsed Nd:YAG laser was used. Other processing parameters such as laser pulse energy, pulse repetition rate, substrate temperature and deposition pressure were identical. The effect of oxygen pressure on the structural properties of the films was systematically studied by using atomic force microscopy. The surface morphology, average roughness Sa, root mean square Sq, and mean size of grains on selected places with 2 × 2 μm2 area of prepared samples were evaluated. Detailed structural analysis confirmed that partial oxygen pressure leads to the modification of surface morphology. Mean grain size in height and lateral direction decreases with raising oxygen pressure from 1 to 5 Pa while the further increase of oxygen pressure from 5 to 35 Pa results in grain size enlargement. The zinc oxide film formed at oxygen partial pressure 5 Pa shows smallest values of evaluated parameters (Sa = 0.6 nm, Sq = 0.7 nm and mean size of grains 50 nm). 相似文献