Graphene has high light transmittance of 97.7% and ultrafast carrier mobility, which means it has attracted widespread attention in two-dimensional materials. However, the optical absorptivity of single-layer graphene...Graphene has high light transmittance of 97.7% and ultrafast carrier mobility, which means it has attracted widespread attention in two-dimensional materials. However, the optical absorptivity of single-layer graphene is only 2.3%, and the corresponding photoresponsivity is difficult to produce at normal light irradiation. And the low on–off ratio resulting from the zero bandgap makes it unsuitable for many electronic devices, hindering potential development. The graphene-based heterojunction composed of graphene and other materials has outstanding optical and electrical properties, which can mutually modify the defects of both the graphene and material making it then suitable for optoelectronic devices. In this review,the advantages of graphene-based heterojunctions in the enhancement of the performance of photodetectors are reviewed.Firstly, we focus on the photocurrent generation mechanism of a graphene-based heterojunction photodetector, especially photovoltaic, photoconduction and photogating effects. Secondly, the classification of graphene-based heterojunctions in different directions is summarized. Meanwhile, the latest research progress of graphene-transition metal dichalcogenide(TMD) heterojunction photodetectors with excellent performance in graphene-based heterostructures is introduced. Finally,the difficulties faced by the existing technologies of graphene-based photodetectors are discussed, and further prospects are proposed.展开更多
Graphene-based nanomaterials(GBNs) have attracted increasing interests of the scientific community due to their unique physicochemical properties and their applications in biotechnology, biomedicine, bioengineering, d...Graphene-based nanomaterials(GBNs) have attracted increasing interests of the scientific community due to their unique physicochemical properties and their applications in biotechnology, biomedicine, bioengineering, disease diagnosis and therapy. Although a large amount of researches have been conducted on these novel nanomaterials, limited comprehensive reviews are published on their biomedical applications and potential environmental and human health effects. The present research aimed at addressing this knowledge gap by examining and discussing:(1) the history, synthesis,structural properties and recent developments of GBNs for biomedical applications;(2) GBNs uses as therapeutics,drug/gene delivery and antibacterial materials;(3) GBNs applications in tissue engineering and in research as biosensors and bioimaging materials; and(4) GBNs potential environmental effects and human health risks. It also discussed the perspectives and challenges associated with the biomedical applications of GBNs.展开更多
A graphene-based tunable dual-band metamaterial absorber which is polarization insensitive is numerically pro- posed at mid-infrared frequencies. In numerical simulation the metamaterial absorber exhibits two absorpti...A graphene-based tunable dual-band metamaterial absorber which is polarization insensitive is numerically pro- posed at mid-infrared frequencies. In numerical simulation the metamaterial absorber exhibits two absorption peaks at the resonance wavelengths of 6.246 μm and 6.837μm when the Fermi level of graphene is fixed at 0. 6 eV. Absorption spectra at different Fermi levels of graphene are displayed and tuning functions are discussed in detail. Both the resonance wavelengths of the absorber blue shift with the increase in Fermi level of graphene. Moreover, the surface current distributions on the gold resonator and ground plane at the two resonance wavelengths are simulated to deeply understand the physical mechanism of resonance absorption.展开更多
DNA/GO composite plays a significant role in the research field of biotechnology and nanotechnology,and attracts a great deal of interest.However,it is still unclear how the oxidation degree of the graphene-based surf...DNA/GO composite plays a significant role in the research field of biotechnology and nanotechnology,and attracts a great deal of interest.However,it is still unclear how the oxidation degree of the graphene-based surface affects the adsorption process of single-strand DNA(ssDNA).In this paper,based on the molecular dynamics simulations,we find that ssDNA molecule is absorbed on the GO surface in the most stable state with the oxidation degree around 15%.The microscopic mechanism is attributed to the van Der Walls and the electrostatic interactions between the ssDNA molecule and the graphene-based surface,which is accompanied with theπ-πstacking and hydrogen bond formation.The number ofπ-πstacking between ssDNA and GO reaches the maximum value when the oxidation degree is around 15%among all the GO surfaces.Our simulation results also reveal the coexistence of stretched and curved configurations as well as the adsorption orientation of ssDNA on the GO surface.Furthermore,it is found that the absorbed ssDNA molecules are more likely to move on the graphene-based surface of low oxidation degree,especially on pristine graphene.Our work provides the physics picture of ssDNA’s physisorption dynamics onto graphene-based surface and it is helpful in designing DNA/GO nanomaterials.展开更多
Graphene is a two-dimensional hexagonal monoatomic layer crystal composed of carbon atoms,which exhibits the shape of a honeycomb and plays an important role in the fields of optics and mechanics.It also has the advan...Graphene is a two-dimensional hexagonal monoatomic layer crystal composed of carbon atoms,which exhibits the shape of a honeycomb and plays an important role in the fields of optics and mechanics.It also has the advantages of high specific surface area,strong chemical stability and special planar structure.It is an ideal carrier for carrying various inorganic compounds and is suitable for the development of high performance graphene-based inorganic nanocomposites.[1]Based on this,the paper introduces the characteristics of graphene,expounds the related content of graphene-based inorganic nanocomposites,and studies the preparation methods and properties of graphene-based inorganic nanocomposites.展开更多
Three-dimensional(3D)functional graphenebased architecture with superior electrical conductivity and good mechanical strength has promising applications in energy storage and electrics.Viscoelasticity-adjustable inks ...Three-dimensional(3D)functional graphenebased architecture with superior electrical conductivity and good mechanical strength has promising applications in energy storage and electrics.Viscoelasticity-adjustable inks make it possible to achieve desired 3D architectures with interconnected and continuous interior networks by microextrusion printing.In this work,ultra-low-concentration graphene oxide(GO)inks of~15 mg·ml-1 have been obtained and demonstrated in direct 3D printing with a facile cross-linking(direct ink writing).The rheological behavior of the GO strategy by cations,which is the lowest concentration to achieve direct ink writing inks,could be adjusted from 1×10^(4) to 1×10^(5) Pa·s^(-1) with different concentrations of cations due to strong cross-linking networks between GO sheets and cations.Meanwhile,the specific strength and electrical conductivity of 3D-printed graphene architecture are notably enhanced,reaching up to 51.7×10^(3) N·m·kg^(-1)and 119 S·m^(-1),which are superior to conventional graphene aerogels.Furthermore,3D printing graphene-based architecture assembled in micro-superc apacitor exhibits excellent electrochemical performance,which can be ascribed to the effective ion transportation through the interconnected networks.The strategy demonstrated is useful in the design of complex-shaped,graphene-based architectures for scalable manufacturing of practical energy storage applications.展开更多
Graphene-based nanomaterials have emerged as a novel type of materials with exceptional physicochemical properties and numerous applications in various areas. In this review, we summarize recent advances in studying i...Graphene-based nanomaterials have emerged as a novel type of materials with exceptional physicochemical properties and numerous applications in various areas. In this review, we summarize recent advances in studying interactions between graphene and biosystems. We first provide a brief introduction on graphene and its derivatives, and then discuss on the toxicology and biocompatibility of graphene, including the extracellular interactions between graphene and biomacromolecules, cellular studies of graphene, and in vivo toxicological effects. Next, we focus on various graphene-based practical applications in antibacterial materials, wound addressing, drug delivery, and water purification.We finally present perspectives on challenges and future developments in these exciting fields.展开更多
Supercapacitors(SCs)have broad applications in wearable electronics(e.g.,e-skin,robots).Recently,graphenebased supercapacitors(G-SCs)have attracted extensive attention for their excellent flexibility and electrochemic...Supercapacitors(SCs)have broad applications in wearable electronics(e.g.,e-skin,robots).Recently,graphenebased supercapacitors(G-SCs)have attracted extensive attention for their excellent flexibility and electrochemical performance.Laser fabrication of G-SCs exhibits obvious superiority because of the simple procedures and integration compatibility with future electronics.Here,we comprehensively summarize the state-of-the-art advancements in laser-assisted preparation of G-SCs,including working mechanisms,fabrication procedures,and unique characteristics.In the working mechanism section,electric double-layer capacitors and pseudocapacitors are introduced.The latest advancements in this field are comprehensively summarized,including laser reduction of graphene oxides,laser treatment of graphene prepared from chemical vapor deposition,and laserinduced graphene.In addition,the unique characteristics of laser-enabled G-SCs,such as structured graphene,graphene hybrids,and heteroatom doping graphene-related electrodes,are presented.Subsequently,laser-enabled miniaturized,stretchable,and integrated G-SCs are also discussed.It is anticipated that laser fabrication of G-SCs holds great promise for developing future energy storage devices.展开更多
Recently,graphene-based materials have been successfully fabricated by the electrophoretic deposition(EPD)technique and exhibited various extraordinary properties.Here,research progress of the field of graphene-based ...Recently,graphene-based materials have been successfully fabricated by the electrophoretic deposition(EPD)technique and exhibited various extraordinary properties.Here,research progress of the field of graphene-based materials prepared by the EPD process in recent 5 years is reviewed,including graphene films,graphene/non-metal composites,graphene/metal-based nanoparticles composites,graphene/polymer composites.We also summarize the experimental deposition conditions and the applications of the deposited graphene-based materials that have been reported.It can be concluded that EPD is a simple and reliable manipulation technique and promises a bright future for the production of graphenebased materials in the field of advanced nanocomposite materials.Finally the current issues and outlook of the development direction of EPD in future are also proposed.展开更多
Nowadays, the yearning for microwave absorption materials(MAMs) are more and more urgent for dealing with the increasingly serious electromagnetic pollution and the demand of modern military security.Among potential c...Nowadays, the yearning for microwave absorption materials(MAMs) are more and more urgent for dealing with the increasingly serious electromagnetic pollution and the demand of modern military security.Among potential candidates, the graphene(GE) based magnetic hybrids have advantages in structural controllable and designing flexibility, providing opportunities for achieving highly efficiency of microwave absorption(MA). Thus, the structural regulation and MA performances of GE-based magnetic hybrids arouse great attention in related fields. In this review, we summarize the recently progress in MA performance of GE-based magnetic hybrids. Typical absorption process and corresponding mechanism are firstly introduced, for guiding the design of GE-based magnetic MAMs. Then, the magnetic components, synthesis methods, structural features and regulation strategies of these GE-related magnetic materials are reviewed, and their influences on MA performances have also been discussed. Challenges, and prospects of the GE-based magnetic MAMs are suggested. This review provides a brief but systematic introduction to GE-based magnetic MAMs, which may pave the way for the design of MAMs with highly efficient MA performances.展开更多
Graphene is a remarkable material with great potential in many applications due to its chemical and physical properties.In this review we briefly present the recent research progress(2016-2018)in graphene and graphene...Graphene is a remarkable material with great potential in many applications due to its chemical and physical properties.In this review we briefly present the recent research progress(2016-2018)in graphene and graphene-based nanomaterials synthesis and discuss the practical aspects of using the materials produced via these methods for different graphene-based applications.展开更多
Despite recent progress in the synthesis and application of graphene-based aerogels, some challenges such as scalable and cost-effective production, and miniaturization still remain, which hinder the practical applica...Despite recent progress in the synthesis and application of graphene-based aerogels, some challenges such as scalable and cost-effective production, and miniaturization still remain, which hinder the practical application of these materials. Here we report a large-scale electrospinning method to generate graphene-based aerogel microspheres (AMs), which show broadband, tunable and high-performance microwave absorption. Graphene/Fe3O4 AMs with a large number of openings with hierarchical connecting radial microcharmels can be obtained via electrospinning-freeze drying followed by calcination. Importantly, for a given Fe3O4:graphene mass ratio, altering the shape of aerogel monoliths or powders into aerogel microspheres leads to unique electromagnetic wave properties. As expected, the reflection loss of graphene/Fe3O4 AMs-1:1 with only 5 wt.% absorber loading reaches -51.5 dB at 9.2 GHz with a thickness of 4.0 mm and a broad absorption bandwidth (RL 〈-10 dB) of 6.5 GHz. Furthermore, switching to coaxial electrospinning enables the fabrication of SiO2 coatings to construct graphene/Fe3O4@SiO2 core-shell AMs. The coatings influence the electromagnetic wave absorption of graphene/Fe3O4 AMs significantly. In view of these advantages, we believe that this processing technique may be extended to fabricate a wide range of unique graphene-based architectures for functional design and applications.展开更多
Graphene, defined as a single atomic plane of graphite, is a semimetal with a small overlap between the valence and conduction bands. The stacking of graphene up to several atomic layers can lead to diverse physical p...Graphene, defined as a single atomic plane of graphite, is a semimetal with a small overlap between the valence and conduction bands. The stacking of graphene up to several atomic layers can lead to diverse physical properties, depending on the stacking method. Bi layer graphene is also a semimetal, adopting the AB-stacked (or Bernal-stacked) structure or the rare AA-stacked structure . Trilayer or few-layer graphene (FLG) can be semimetals or semiconductors, depending on whether they adopt Bernal (ABA) stacking or rhoinbohedral (ABC) stacking.展开更多
We systematically investigated the tunable dynamic characteristics of a broadband surface plasmon polariton(SPP) wave on a silicon-graded grating structure in the range of 10–40 THz with the aid of single-layer graph...We systematically investigated the tunable dynamic characteristics of a broadband surface plasmon polariton(SPP) wave on a silicon-graded grating structure in the range of 10–40 THz with the aid of single-layer graphene.The theoretical and numerical simulated results demonstrate that the SPPs at different frequencies within a broadband range can be trapped at different positions on the graphene surface, which can be used as a broadband spectrometer and optical switch. Meanwhile, the group velocity of the SPPs can be modulated to be several hundred times smaller than light velocity in vacuum. Based on the theoretical analyses, we have predicted the trapping positions and corresponding group velocities of the SPP waves with different frequencies. By appropriately tuning the gate voltages, the trapped SPP waves can be released to propagate along the surface of graphene or out of the graded grating zone. Thus, we have also investigated the switching characteristics of the slow light system, where the optical switching can be controlled as an "off" or "on" mode by actively adjusting the gate voltage. The slow light system offers advantages, including broadband operation, ultracompact footprint, and tunable ability simultaneously, which holds great promise for applications in optical switches.展开更多
In this study, new nano spherical graphene modified with LDH(Layered Double Hydroxide) was prepared and used to remove As(Ⅲ) ion from aqueous solutions. At first, graphene oxide was synthesized from graphite using a ...In this study, new nano spherical graphene modified with LDH(Layered Double Hydroxide) was prepared and used to remove As(Ⅲ) ion from aqueous solutions. At first, graphene oxide was synthesized from graphite using a well-known Hammer method. The obtained graphene oxide solution was sprayed in octanol solution under different temperatures and sprayed speed as influenced variables. The structure and physical characterization of synthesized spherical graphene oxide were determined by various techniques,including FT-IR, N_(2) adsorption–desorption, SEM, TEM, and EDX. In the next step, the hydrothermal method was applied to deposition LDH on the spherical graphene oxide. The synthesized spherical graphene modified by LDH was used to remove As(Ⅲ) as a toxic heavy metal ion. The effect of influenced variables including p H, contact time, amount of sorbent, and type eluent studied and the optimum values were as 8, 30, 50, and HCl(0.5 mol·L^(-1)), respectively. After optimization, the studied sorbent was shown a high adsorption capacity(149.3 mg·g^(-1)). The adsorption mechanism and kinetic models exhibited good agreement with the Langmuir isotherm and pseudo-second-order trends, respectively. Besides, the synthesized product was tested for seven times without significant loss in its sorption efficiency.展开更多
In the present work,we developed a micellar system of milk protein-surfactant(SDS)-graphene to prepare the graphene-based aerogels via hydrothermal and freeze-drying method,in which the novel surface-property of aerog...In the present work,we developed a micellar system of milk protein-surfactant(SDS)-graphene to prepare the graphene-based aerogels via hydrothermal and freeze-drying method,in which the novel surface-property of aerogels can be tuned with the decreasing of micellar size in the colloid systems resulting the improved specific surface area.The milk protein also severed as green and sustainable sources to introduce nitrogen heteroatoms into the aerogels.Subsequently,the aerogels were further graphitized and activated to fabricate N-doped porous nanocarbon at 600℃.The initial surface composition and structure of the aerogel,which was proved,has obvious impact on the final structure of the synthesized nanocarbon materials,and thus influence their electrochemical activity.The optimized nanocarbon materials(MGPC-5),with enhanced specific surface area,degree of graphitization,and nitrogen doping,exhibited excellent capacitance performance and stability in both three-electrode system(518.8 F/g at a current density of 0.1 A/g)and symmetrical electrode system(120.8 F/g at current density of 0.1 A/g and with^95%capacitance retention after 5000 cycles of charging and discharging at 3 A/g)in KOH.The assembled supercapacitor also shows ideal capacitive properties in series and parallel configurations.Tested with a stable 1.6 V windows in Li2SO4 electrolyte,the symmetric supercapacitor cell exhibits a high energy density up to 36.7 W h/kg.The present work provides a feasible fabrication method for high-performance supercapacitor based on graphene and biomass derived carbon,the proposed surfaceproperty regulation and supercapacitor performance improvement strategy may also shed light on other energy related materials or system.展开更多
The development of convenient method to obtain graphene-based nanocomposites is a key issue for their application. Herein, we described a facile route for synthesizing graphene-Cu and graphene-Cu2 O nanocomposites usi...The development of convenient method to obtain graphene-based nanocomposites is a key issue for their application. Herein, we described a facile route for synthesizing graphene-Cu and graphene-Cu2 O nanocomposites using graphene oxide-Cu O as a precursor. Remarkably, the different nanocomposites could be formed just by varying the reaction temperature and time. This work provides a feasible route for the preparation of graphene-based nanocomposites with various constituents.展开更多
Graphene-based resistive random access memory (GRRAM) has grasped researchers' attention due to its merits com- pared with ordinary RRAM. In this paper, we briefly review different types of GRRAMs. These GRRAMs can...Graphene-based resistive random access memory (GRRAM) has grasped researchers' attention due to its merits com- pared with ordinary RRAM. In this paper, we briefly review different types of GRRAMs. These GRRAMs can be divided into two categories: graphene RRAM and graphene oxide (GO)/reduced graphene oxide (rGO) RRAM. Using graphene as the electrode, GRRAM can own many good characteristics, such as low power consumption, higher density, transparency, SET voltage modulation, high uniformity, and so on. Graphene flakes sandwiched between two dielectric layers can lower the SET voltage and achieve multilevel switching. Moreover, the GRRAM with rGO and GO as the dielectric or electrode can be simply fabricated. Flexible and high performance RRAM and GO film can be modified by adding other materials layer or making a composite with polymer, nanoparticle, and 2D materials to further improve the performance. Above all, GRRAM shows huge potential to become the next generation memory.展开更多
Solar-driven water evaporation is a sustainable method to purify seawater.Nevertheless,traditional volumetric water-evaporation systems suffer from the poor sunlight absorption and inefficient light-to-thermal convers...Solar-driven water evaporation is a sustainable method to purify seawater.Nevertheless,traditional volumetric water-evaporation systems suffer from the poor sunlight absorption and inefficient light-to-thermal conversion.Also,their anti-bacterial and antifouling performances are crucial for the practical application.Herein,we introduce reduced graphene oxide(RGO)with broadband absorbance across the entire solar spectrum,and polypyrrole(PPy),an antibacterial polymer with efficient solar absorption and low thermal conductivity,to develop integrated RGO/PPy aerogel as both the solar absorber and evaporator for highly efficient solar-driven steam generation.As a result,the RGO/PPy aerogel shows strong absorption and good photothermal performance,leading to an evaporation rate of 1.44 kg·m^(−2)·h^(−1)and high salt rejection(up to 99.99%)for real seawater,with photothermal conversion efficiency>90%under one sun irradiation.The result is attributed to the localized heat at the air-water interface by the RGO/PPy and its porous nature with functional groups that facilitates the water evaporation.Moreover,the RGO/PPy demonstrates excellent durability and antibacterial efficiency close to 100%for 12 h,crucial characteristics for longterm application.Our well-designed RGO/PPy aerogel with efficient water desalination performance and antibacterial property provides a straightforward approach to improve the solar-driven evaporation performance by multifunctional materials integration,and offers a viable route towards practical seawater desalination.展开更多
In recent years,graphene-based composite films have been greatly developed in the field of electromagnetic shielding interference(EMI).However,it is still a huge challenge to prepare graphene-based composite films wit...In recent years,graphene-based composite films have been greatly developed in the field of electromagnetic shielding interference(EMI).However,it is still a huge challenge to prepare graphene-based composite films with excellent mechanical properties,conductivity and electromagnetic shielding properties.In this work,we adopted a facile and effective method by annealing the alkali-treated polyacrylonitrile(aPAN)nanofibers reinforced graphene oxide(GO)composite films at 2000°C to obtain graphene-carbon nanofibers composite films(GCFs).Microscopically,carbon nanofibers(CNFs)were intercalated into the graphene sheets,and microgasbags structure was formed during the heat treatment process.The special structure makes GCFs have superior tensile strength(10.4 MPa)at 5%strain.After repeated folding over1000 times,the films still demonstrate excellent structural integrity and flexibility performance.Interestingly,the graphene-based composite films with 10 wt%a PAN nanofibers exhibit an extremely low density of about 0.678 g/cm^(3)and excellent electrical conductivity of 1.72×10^(5)S/m.Further,an outstanding electromagnetic shielding effectiveness(SE)of 55–57 d B was achieved,and the corresponding value of the specific SE/thickness can reach 67,601–70,059 d B·cm^(2)/g,which is the highest among reported graphenebased shielding materials.The significant electromagnetic shielding performance is due to the synergistic enhancement effect brought by the excellent conductivity of carbon nanofibers and graphene,the formed effective conductive network and the microgasbags structure.Electromagnetism simulation further clarified that the underlying mechanism should be mainly attributed to the conduction loss and multiple reflections caused by the special structure of GCFs.This work will provide new solutions for low density,high flexibility and excellent electromagnetic shielding properties materials in the next generation of foldable and wearable electronics.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No. 61771467)Shanxi Scholarship Council of China (Grant No. 2020-112)+1 种基金Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi, China (Grant Nos. 2020L0268 and 2020L0307)Science Foundation of North University of China (Grant No. XJJ201915)。
文摘Graphene has high light transmittance of 97.7% and ultrafast carrier mobility, which means it has attracted widespread attention in two-dimensional materials. However, the optical absorptivity of single-layer graphene is only 2.3%, and the corresponding photoresponsivity is difficult to produce at normal light irradiation. And the low on–off ratio resulting from the zero bandgap makes it unsuitable for many electronic devices, hindering potential development. The graphene-based heterojunction composed of graphene and other materials has outstanding optical and electrical properties, which can mutually modify the defects of both the graphene and material making it then suitable for optoelectronic devices. In this review,the advantages of graphene-based heterojunctions in the enhancement of the performance of photodetectors are reviewed.Firstly, we focus on the photocurrent generation mechanism of a graphene-based heterojunction photodetector, especially photovoltaic, photoconduction and photogating effects. Secondly, the classification of graphene-based heterojunctions in different directions is summarized. Meanwhile, the latest research progress of graphene-transition metal dichalcogenide(TMD) heterojunction photodetectors with excellent performance in graphene-based heterostructures is introduced. Finally,the difficulties faced by the existing technologies of graphene-based photodetectors are discussed, and further prospects are proposed.
基金supported by National Institutes of Heath NIMHD Grant # G12MD007581 through the RCMI Center for Environmental HealthNational Science Foundation Grant # HRD-1547754 through the CREST Center for Nanotoxicity Studies at Jackson State University
文摘Graphene-based nanomaterials(GBNs) have attracted increasing interests of the scientific community due to their unique physicochemical properties and their applications in biotechnology, biomedicine, bioengineering, disease diagnosis and therapy. Although a large amount of researches have been conducted on these novel nanomaterials, limited comprehensive reviews are published on their biomedical applications and potential environmental and human health effects. The present research aimed at addressing this knowledge gap by examining and discussing:(1) the history, synthesis,structural properties and recent developments of GBNs for biomedical applications;(2) GBNs uses as therapeutics,drug/gene delivery and antibacterial materials;(3) GBNs applications in tissue engineering and in research as biosensors and bioimaging materials; and(4) GBNs potential environmental effects and human health risks. It also discussed the perspectives and challenges associated with the biomedical applications of GBNs.
基金Supported by the National Natural Science Foundation of China under Grant No 61001018the Natural Science Foundation of Shandong Province under Grant No ZR2012FM011+4 种基金the Shandong-Provincial Higher Educational Science and Technology Program under Grant No J11LG20the Qingdao City Innovative Leading Talent Plan under Grant No 13-CX-25the THz Science and Technology Foundation of China Academy of Engineering Physics under Grant No 201401the Qingdao Economic and Technical Development Zone Science and Technology Project under Grant No 2013-1-64the Shandong University of Science and Technology Foundation under Grant No YC140108
文摘A graphene-based tunable dual-band metamaterial absorber which is polarization insensitive is numerically pro- posed at mid-infrared frequencies. In numerical simulation the metamaterial absorber exhibits two absorption peaks at the resonance wavelengths of 6.246 μm and 6.837μm when the Fermi level of graphene is fixed at 0. 6 eV. Absorption spectra at different Fermi levels of graphene are displayed and tuning functions are discussed in detail. Both the resonance wavelengths of the absorber blue shift with the increase in Fermi level of graphene. Moreover, the surface current distributions on the gold resonator and ground plane at the two resonance wavelengths are simulated to deeply understand the physical mechanism of resonance absorption.
基金supported by the National Natural Science Foundation of China(Grant Nos.11305237 and 11974366)the Fundamental Research Funds for the Central Universities,China,the Natural Science Foundation of Shanghai,China(Grant No.19ZR1463200)the Key Research Program of Chinese Academy of Sciences(Grant No.QYZDJ-SSW-SLH053).
文摘DNA/GO composite plays a significant role in the research field of biotechnology and nanotechnology,and attracts a great deal of interest.However,it is still unclear how the oxidation degree of the graphene-based surface affects the adsorption process of single-strand DNA(ssDNA).In this paper,based on the molecular dynamics simulations,we find that ssDNA molecule is absorbed on the GO surface in the most stable state with the oxidation degree around 15%.The microscopic mechanism is attributed to the van Der Walls and the electrostatic interactions between the ssDNA molecule and the graphene-based surface,which is accompanied with theπ-πstacking and hydrogen bond formation.The number ofπ-πstacking between ssDNA and GO reaches the maximum value when the oxidation degree is around 15%among all the GO surfaces.Our simulation results also reveal the coexistence of stretched and curved configurations as well as the adsorption orientation of ssDNA on the GO surface.Furthermore,it is found that the absorbed ssDNA molecules are more likely to move on the graphene-based surface of low oxidation degree,especially on pristine graphene.Our work provides the physics picture of ssDNA’s physisorption dynamics onto graphene-based surface and it is helpful in designing DNA/GO nanomaterials.
文摘Graphene is a two-dimensional hexagonal monoatomic layer crystal composed of carbon atoms,which exhibits the shape of a honeycomb and plays an important role in the fields of optics and mechanics.It also has the advantages of high specific surface area,strong chemical stability and special planar structure.It is an ideal carrier for carrying various inorganic compounds and is suitable for the development of high performance graphene-based inorganic nanocomposites.[1]Based on this,the paper introduces the characteristics of graphene,expounds the related content of graphene-based inorganic nanocomposites,and studies the preparation methods and properties of graphene-based inorganic nanocomposites.
基金financially supported by the National Natural Science Foundation of China(No.51802195)Chen Guang Scholar Project of Shanghai Education Commission(No.19CG53)。
文摘Three-dimensional(3D)functional graphenebased architecture with superior electrical conductivity and good mechanical strength has promising applications in energy storage and electrics.Viscoelasticity-adjustable inks make it possible to achieve desired 3D architectures with interconnected and continuous interior networks by microextrusion printing.In this work,ultra-low-concentration graphene oxide(GO)inks of~15 mg·ml-1 have been obtained and demonstrated in direct 3D printing with a facile cross-linking(direct ink writing).The rheological behavior of the GO strategy by cations,which is the lowest concentration to achieve direct ink writing inks,could be adjusted from 1×10^(4) to 1×10^(5) Pa·s^(-1) with different concentrations of cations due to strong cross-linking networks between GO sheets and cations.Meanwhile,the specific strength and electrical conductivity of 3D-printed graphene architecture are notably enhanced,reaching up to 51.7×10^(3) N·m·kg^(-1)and 119 S·m^(-1),which are superior to conventional graphene aerogels.Furthermore,3D printing graphene-based architecture assembled in micro-superc apacitor exhibits excellent electrochemical performance,which can be ascribed to the effective ion transportation through the interconnected networks.The strategy demonstrated is useful in the design of complex-shaped,graphene-based architectures for scalable manufacturing of practical energy storage applications.
基金the National Key Research and Development Program (No. 2016YFA0201200)the Shanghai Municipal Natural Science Foundation (No. 17ZR1412100)+1 种基金the Key Laboratory of Interfacial Physics and Technology, the Chinese Academy of Sciences (No. CASKL-IPT1603)the Talent Program of Shanghai University of Engineering Science, the Startup Foundation for Doctors of Shanghai University of Engineering Science, and the National Natural Science Foundation of China (Nos. 81870749, 21373260, 31470960 and 51375294).
文摘Graphene-based nanomaterials have emerged as a novel type of materials with exceptional physicochemical properties and numerous applications in various areas. In this review, we summarize recent advances in studying interactions between graphene and biosystems. We first provide a brief introduction on graphene and its derivatives, and then discuss on the toxicology and biocompatibility of graphene, including the extracellular interactions between graphene and biomacromolecules, cellular studies of graphene, and in vivo toxicological effects. Next, we focus on various graphene-based practical applications in antibacterial materials, wound addressing, drug delivery, and water purification.We finally present perspectives on challenges and future developments in these exciting fields.
基金National Key Research and Development Program of China(2017YFB1104600)National Natural Science Foundation of China(61935008,61775078,61905087,61590930)Scientific and Technological Developing Scheme of Jilin Province(20180101061JC)。
文摘Supercapacitors(SCs)have broad applications in wearable electronics(e.g.,e-skin,robots).Recently,graphenebased supercapacitors(G-SCs)have attracted extensive attention for their excellent flexibility and electrochemical performance.Laser fabrication of G-SCs exhibits obvious superiority because of the simple procedures and integration compatibility with future electronics.Here,we comprehensively summarize the state-of-the-art advancements in laser-assisted preparation of G-SCs,including working mechanisms,fabrication procedures,and unique characteristics.In the working mechanism section,electric double-layer capacitors and pseudocapacitors are introduced.The latest advancements in this field are comprehensively summarized,including laser reduction of graphene oxides,laser treatment of graphene prepared from chemical vapor deposition,and laserinduced graphene.In addition,the unique characteristics of laser-enabled G-SCs,such as structured graphene,graphene hybrids,and heteroatom doping graphene-related electrodes,are presented.Subsequently,laser-enabled miniaturized,stretchable,and integrated G-SCs are also discussed.It is anticipated that laser fabrication of G-SCs holds great promise for developing future energy storage devices.
文摘Recently,graphene-based materials have been successfully fabricated by the electrophoretic deposition(EPD)technique and exhibited various extraordinary properties.Here,research progress of the field of graphene-based materials prepared by the EPD process in recent 5 years is reviewed,including graphene films,graphene/non-metal composites,graphene/metal-based nanoparticles composites,graphene/polymer composites.We also summarize the experimental deposition conditions and the applications of the deposited graphene-based materials that have been reported.It can be concluded that EPD is a simple and reliable manipulation technique and promises a bright future for the production of graphenebased materials in the field of advanced nanocomposite materials.Finally the current issues and outlook of the development direction of EPD in future are also proposed.
基金financially supported by National Natural Science Foudation of China (Grant No.51573149)the Science and Technology Planning Projects of Sichuan Province (Grant Nos.2020ZDZX0005,2020ZDZX0008)。
文摘Nowadays, the yearning for microwave absorption materials(MAMs) are more and more urgent for dealing with the increasingly serious electromagnetic pollution and the demand of modern military security.Among potential candidates, the graphene(GE) based magnetic hybrids have advantages in structural controllable and designing flexibility, providing opportunities for achieving highly efficiency of microwave absorption(MA). Thus, the structural regulation and MA performances of GE-based magnetic hybrids arouse great attention in related fields. In this review, we summarize the recently progress in MA performance of GE-based magnetic hybrids. Typical absorption process and corresponding mechanism are firstly introduced, for guiding the design of GE-based magnetic MAMs. Then, the magnetic components, synthesis methods, structural features and regulation strategies of these GE-related magnetic materials are reviewed, and their influences on MA performances have also been discussed. Challenges, and prospects of the GE-based magnetic MAMs are suggested. This review provides a brief but systematic introduction to GE-based magnetic MAMs, which may pave the way for the design of MAMs with highly efficient MA performances.
文摘Graphene is a remarkable material with great potential in many applications due to its chemical and physical properties.In this review we briefly present the recent research progress(2016-2018)in graphene and graphene-based nanomaterials synthesis and discuss the practical aspects of using the materials produced via these methods for different graphene-based applications.
基金This work was financially supported by the National Natural Science Foundation of China (No. 51573149), the Science and Technology Planning Project of Sichuan Province (No. 2016GZ0224), the Fundamental Research Funds for the Central Universities (No. 2682016CX069) and the Student Research Training Program (No. 2017005).
文摘Despite recent progress in the synthesis and application of graphene-based aerogels, some challenges such as scalable and cost-effective production, and miniaturization still remain, which hinder the practical application of these materials. Here we report a large-scale electrospinning method to generate graphene-based aerogel microspheres (AMs), which show broadband, tunable and high-performance microwave absorption. Graphene/Fe3O4 AMs with a large number of openings with hierarchical connecting radial microcharmels can be obtained via electrospinning-freeze drying followed by calcination. Importantly, for a given Fe3O4:graphene mass ratio, altering the shape of aerogel monoliths or powders into aerogel microspheres leads to unique electromagnetic wave properties. As expected, the reflection loss of graphene/Fe3O4 AMs-1:1 with only 5 wt.% absorber loading reaches -51.5 dB at 9.2 GHz with a thickness of 4.0 mm and a broad absorption bandwidth (RL 〈-10 dB) of 6.5 GHz. Furthermore, switching to coaxial electrospinning enables the fabrication of SiO2 coatings to construct graphene/Fe3O4@SiO2 core-shell AMs. The coatings influence the electromagnetic wave absorption of graphene/Fe3O4 AMs significantly. In view of these advantages, we believe that this processing technique may be extended to fabricate a wide range of unique graphene-based architectures for functional design and applications.
文摘Graphene, defined as a single atomic plane of graphite, is a semimetal with a small overlap between the valence and conduction bands. The stacking of graphene up to several atomic layers can lead to diverse physical properties, depending on the stacking method. Bi layer graphene is also a semimetal, adopting the AB-stacked (or Bernal-stacked) structure or the rare AA-stacked structure . Trilayer or few-layer graphene (FLG) can be semimetals or semiconductors, depending on whether they adopt Bernal (ABA) stacking or rhoinbohedral (ABC) stacking.
基金Fundamental Research Funds for the Central Universities(JD2017JGPY0005)National Natural Science Foundation of China(NSFC)(61775050)
文摘We systematically investigated the tunable dynamic characteristics of a broadband surface plasmon polariton(SPP) wave on a silicon-graded grating structure in the range of 10–40 THz with the aid of single-layer graphene.The theoretical and numerical simulated results demonstrate that the SPPs at different frequencies within a broadband range can be trapped at different positions on the graphene surface, which can be used as a broadband spectrometer and optical switch. Meanwhile, the group velocity of the SPPs can be modulated to be several hundred times smaller than light velocity in vacuum. Based on the theoretical analyses, we have predicted the trapping positions and corresponding group velocities of the SPP waves with different frequencies. By appropriately tuning the gate voltages, the trapped SPP waves can be released to propagate along the surface of graphene or out of the graded grating zone. Thus, we have also investigated the switching characteristics of the slow light system, where the optical switching can be controlled as an "off" or "on" mode by actively adjusting the gate voltage. The slow light system offers advantages, including broadband operation, ultracompact footprint, and tunable ability simultaneously, which holds great promise for applications in optical switches.
文摘In this study, new nano spherical graphene modified with LDH(Layered Double Hydroxide) was prepared and used to remove As(Ⅲ) ion from aqueous solutions. At first, graphene oxide was synthesized from graphite using a well-known Hammer method. The obtained graphene oxide solution was sprayed in octanol solution under different temperatures and sprayed speed as influenced variables. The structure and physical characterization of synthesized spherical graphene oxide were determined by various techniques,including FT-IR, N_(2) adsorption–desorption, SEM, TEM, and EDX. In the next step, the hydrothermal method was applied to deposition LDH on the spherical graphene oxide. The synthesized spherical graphene modified by LDH was used to remove As(Ⅲ) as a toxic heavy metal ion. The effect of influenced variables including p H, contact time, amount of sorbent, and type eluent studied and the optimum values were as 8, 30, 50, and HCl(0.5 mol·L^(-1)), respectively. After optimization, the studied sorbent was shown a high adsorption capacity(149.3 mg·g^(-1)). The adsorption mechanism and kinetic models exhibited good agreement with the Langmuir isotherm and pseudo-second-order trends, respectively. Besides, the synthesized product was tested for seven times without significant loss in its sorption efficiency.
基金financial support from the NSFC of China(21761132010,91645114 and 21573256)the Youth Innovation Promotion Association,CAS,China。
文摘In the present work,we developed a micellar system of milk protein-surfactant(SDS)-graphene to prepare the graphene-based aerogels via hydrothermal and freeze-drying method,in which the novel surface-property of aerogels can be tuned with the decreasing of micellar size in the colloid systems resulting the improved specific surface area.The milk protein also severed as green and sustainable sources to introduce nitrogen heteroatoms into the aerogels.Subsequently,the aerogels were further graphitized and activated to fabricate N-doped porous nanocarbon at 600℃.The initial surface composition and structure of the aerogel,which was proved,has obvious impact on the final structure of the synthesized nanocarbon materials,and thus influence their electrochemical activity.The optimized nanocarbon materials(MGPC-5),with enhanced specific surface area,degree of graphitization,and nitrogen doping,exhibited excellent capacitance performance and stability in both three-electrode system(518.8 F/g at a current density of 0.1 A/g)and symmetrical electrode system(120.8 F/g at current density of 0.1 A/g and with^95%capacitance retention after 5000 cycles of charging and discharging at 3 A/g)in KOH.The assembled supercapacitor also shows ideal capacitive properties in series and parallel configurations.Tested with a stable 1.6 V windows in Li2SO4 electrolyte,the symmetric supercapacitor cell exhibits a high energy density up to 36.7 W h/kg.The present work provides a feasible fabrication method for high-performance supercapacitor based on graphene and biomass derived carbon,the proposed surfaceproperty regulation and supercapacitor performance improvement strategy may also shed light on other energy related materials or system.
基金Funded by the Jiangsu Funds for Distinguished Young Scientists(No.BK2012035)Program for New Century Excellent Talents in University(No.NCET-11-0834)the National Natural Science Foundation of China(No.21206075)
文摘The development of convenient method to obtain graphene-based nanocomposites is a key issue for their application. Herein, we described a facile route for synthesizing graphene-Cu and graphene-Cu2 O nanocomposites using graphene oxide-Cu O as a precursor. Remarkably, the different nanocomposites could be formed just by varying the reaction temperature and time. This work provides a feasible route for the preparation of graphene-based nanocomposites with various constituents.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61574083 and 61434001)the National Basic Research Program of China(Grant No.2015CB352101)+4 种基金the National Key Research and Development Program of China(Grant No.2016YFA0200404)the National Key Project of Science and Technology of China(Grant No.2011ZX02403-002)Special Fund for Agroscientic Research in the Public Interest of China(Grant No.201303107)the Independent Research Program of Tsinghua University,China(Grant No.2014Z01006)Advanced Sensor and Integrated System Lab of Tsinghua University Graduate School at Shenzhen,China(Grant No.ZDSYS20140509172959969)
文摘Graphene-based resistive random access memory (GRRAM) has grasped researchers' attention due to its merits com- pared with ordinary RRAM. In this paper, we briefly review different types of GRRAMs. These GRRAMs can be divided into two categories: graphene RRAM and graphene oxide (GO)/reduced graphene oxide (rGO) RRAM. Using graphene as the electrode, GRRAM can own many good characteristics, such as low power consumption, higher density, transparency, SET voltage modulation, high uniformity, and so on. Graphene flakes sandwiched between two dielectric layers can lower the SET voltage and achieve multilevel switching. Moreover, the GRRAM with rGO and GO as the dielectric or electrode can be simply fabricated. Flexible and high performance RRAM and GO film can be modified by adding other materials layer or making a composite with polymer, nanoparticle, and 2D materials to further improve the performance. Above all, GRRAM shows huge potential to become the next generation memory.
基金supported by the National Key R&D Program of China(Nos.2018YFA0209500 and 2018YFA0306900)the National Natural Science Foundation of China(Nos.21872114 and 21627811).
文摘Solar-driven water evaporation is a sustainable method to purify seawater.Nevertheless,traditional volumetric water-evaporation systems suffer from the poor sunlight absorption and inefficient light-to-thermal conversion.Also,their anti-bacterial and antifouling performances are crucial for the practical application.Herein,we introduce reduced graphene oxide(RGO)with broadband absorbance across the entire solar spectrum,and polypyrrole(PPy),an antibacterial polymer with efficient solar absorption and low thermal conductivity,to develop integrated RGO/PPy aerogel as both the solar absorber and evaporator for highly efficient solar-driven steam generation.As a result,the RGO/PPy aerogel shows strong absorption and good photothermal performance,leading to an evaporation rate of 1.44 kg·m^(−2)·h^(−1)and high salt rejection(up to 99.99%)for real seawater,with photothermal conversion efficiency>90%under one sun irradiation.The result is attributed to the localized heat at the air-water interface by the RGO/PPy and its porous nature with functional groups that facilitates the water evaporation.Moreover,the RGO/PPy demonstrates excellent durability and antibacterial efficiency close to 100%for 12 h,crucial characteristics for longterm application.Our well-designed RGO/PPy aerogel with efficient water desalination performance and antibacterial property provides a straightforward approach to improve the solar-driven evaporation performance by multifunctional materials integration,and offers a viable route towards practical seawater desalination.
基金financially supported by the National Natural Science Foundation of China(NSFC,No.51903213 and No.5217130190)the Science and Technology Planning Project of Sichuan Province(No.2020YFH0053)Central Government Guides the Local Science and Technology Development Special Funds to freely explore basic research projects(No.2021Szvup124)。
文摘In recent years,graphene-based composite films have been greatly developed in the field of electromagnetic shielding interference(EMI).However,it is still a huge challenge to prepare graphene-based composite films with excellent mechanical properties,conductivity and electromagnetic shielding properties.In this work,we adopted a facile and effective method by annealing the alkali-treated polyacrylonitrile(aPAN)nanofibers reinforced graphene oxide(GO)composite films at 2000°C to obtain graphene-carbon nanofibers composite films(GCFs).Microscopically,carbon nanofibers(CNFs)were intercalated into the graphene sheets,and microgasbags structure was formed during the heat treatment process.The special structure makes GCFs have superior tensile strength(10.4 MPa)at 5%strain.After repeated folding over1000 times,the films still demonstrate excellent structural integrity and flexibility performance.Interestingly,the graphene-based composite films with 10 wt%a PAN nanofibers exhibit an extremely low density of about 0.678 g/cm^(3)and excellent electrical conductivity of 1.72×10^(5)S/m.Further,an outstanding electromagnetic shielding effectiveness(SE)of 55–57 d B was achieved,and the corresponding value of the specific SE/thickness can reach 67,601–70,059 d B·cm^(2)/g,which is the highest among reported graphenebased shielding materials.The significant electromagnetic shielding performance is due to the synergistic enhancement effect brought by the excellent conductivity of carbon nanofibers and graphene,the formed effective conductive network and the microgasbags structure.Electromagnetism simulation further clarified that the underlying mechanism should be mainly attributed to the conduction loss and multiple reflections caused by the special structure of GCFs.This work will provide new solutions for low density,high flexibility and excellent electromagnetic shielding properties materials in the next generation of foldable and wearable electronics.