Carbon coatings for silicon(Si)-based anode materials are essential for designing high-performance Li-ion batteries(LIBs).The coatings prevent direct contact with the electrolyte and enhance anode performance.However,...Carbon coatings for silicon(Si)-based anode materials are essential for designing high-performance Li-ion batteries(LIBs).The coatings prevent direct contact with the electrolyte and enhance anode performance.However,conventional carbon coatings are limited by their volume expansion and structural degradation,which lead to capacity fading and reduced durability.This study introduces a scalable and practical one-step carbon-coating strategy for directly coating silicon suboxide(SiO_(x))-based materials using aqueous quasi-defect-free reduced graphene oxide(QrGO)without post-treatment,unlike conventional graphene oxide(GO)-based coating methods.This simple process enables uniform encapsulation with QrGO for a highly adhesive and conductive coating.The QrGO-based composite anode material has several advantages,including reduced cracking due to volume expansion and enhanced charge carrier transport,as well as an increased Si content of 20 wt.%compared to the 5 wt.%in typical commercial Si-based active materials.In particular,the capacity retention of the QrGO-coated Si electrodes dramatically increases at high C-rate.The full cell exhibited long-term stability and capacity that were twice that of commercial SiO_(x)-based cells.Therefore,the QrGO-based one-step coating process represents a scalable,transformative,and commercially viable strategy for developing high-performance LIBs.展开更多
Silicon-air batteries(SABs),a new type of semiconductor air battery,have a high energy density.However,some side reactions in SABs cause Si anodes to be covered by a passivation layer to prevent continuous discharge,a...Silicon-air batteries(SABs),a new type of semiconductor air battery,have a high energy density.However,some side reactions in SABs cause Si anodes to be covered by a passivation layer to prevent continuous discharge,and the anode utilization rate is low.In this work,reduced graphene oxide(RGO)fabricated via high-temperature annealing or L-ascorbic acid(L.AA)reduction was first used to obtain Si nanowires/RGO-1000(Si NWs/RGO-1000)and Si nanowires/RGO-L.AA(Si NWs/RGO-L.AA)composite anodes for SABs.It was found that RGO suppressed the passivation and self-corrosion reactions and that SABs using Si NWs/RGO-L.AA as the anode can discharge for more than 700 h,breaking the previous performance of SABs,and that the specific capacity was increased by 90.8%compared to bare Si.This work provides a new solution for the design of high specific capacity SABs with nanostructures and anode protective layers.展开更多
Fast electron-hole recombination issues during titanium dioxide(TiO_(2))photocatalysis limit its application in preventing bacterial infection during bone defect repair.In this study,TiO_(2)@reduced graphene oxide(rGO...Fast electron-hole recombination issues during titanium dioxide(TiO_(2))photocatalysis limit its application in preventing bacterial infection during bone defect repair.In this study,TiO_(2)@reduced graphene oxide(rGO)composites were synthesized using a hydrothermal method in which rGO,which possesses very high electrical conductivity,promotes the separation of photoelectron-hole pairs of TiO_(2),thus improving the efficiency of photocatalytic production of reactive oxygen species(ROS).Subsequently,TiO_(2)@rGO composites were introduced into poly-L-lactic acid(PLLA)to prepare bone scaffolds with photocatalytic antibacterial function via selective laser sintering.The results showed that TiO_(2)grew on the surface of rGO and formed a covalent bond connection(Ti-O-C)with rGO.A decreased electrochemical impedance of TiO_(2)@rGO composites was observed,and the transient photocurrent intensity increased from 0.05 to 0.5μA/cm^(2).Analysis of electron spin resonance found that the photocatalytic products of TiO_(2)were·OH and·O^(2-),two kinds of ROS capable of killing bacteria via disrupting the structure of the bacterial membrane in vitro.Antibacterial experiments showed that the PLLA/TiO_(2)@rGO scaffolds had good antibacterial properties against Escherichia coli and Staphylococcus aureus.Finally,we report that these scaffolds exhibited both enhanced mechanical properties due to the addition of TiO_(2)@rGO as a reinforcement material and good biocompatibility during cell proliferation.展开更多
Carbon-based foams with a three-dimensional structure can serve as a lightweight template for the rational design and control-lable preparation of metal oxide/carbon-based composite microwave absorption materials.In t...Carbon-based foams with a three-dimensional structure can serve as a lightweight template for the rational design and control-lable preparation of metal oxide/carbon-based composite microwave absorption materials.In this study,a flake-like nickel cobaltate/re-duced graphene oxide/melamine-derived carbon foam(FNC/RGO/MDCF)was successfully fabricated through a combination of solvo-thermal treatment and high-temperature pyrolysis.Results indicated that RGO was evenly distributed in the MDCF skeleton,providing ef-fective support for the load growth of FNC on its surface.Sample S3,the FNC/RGO/MDCF composite prepared by solvothermal method for 16 h,exhibited a minimum reflection loss(RL_(min))of-66.44 dB at a thickness of 2.29 mm.When the thickness was reduced to 1.50 mm,the optimal effective absorption bandwidth was 3.84 GHz.Analysis of the absorption mechanism of FNC/RGO/MDCF revealed that its excellent absorption performance was primarily attributed to the combined effects of conduction loss,multiple reflection,scattering,in-terface polarization,and dipole polarization.展开更多
The indiscriminate use and disposal of ciprofloxacin(CIP)have led to its detection in water globally,which pose a huge risk to public health and water environment.Herein,(Zn-Al)LDHs modified 3D reduced graphene oxide ...The indiscriminate use and disposal of ciprofloxacin(CIP)have led to its detection in water globally,which pose a huge risk to public health and water environment.Herein,(Zn-Al)LDHs modified 3D reduced graphene oxide nanocomposite((Zn-Al)LDHs/3D-rGO)was synthesized through a feasible onepot hydrothermal method for CIP removal.The highly distributed(Zn-Al)LDHs flakes on the surface of 3D-rGO endow the resulted(Zn-Al)LDHs/3D-rGO with an excellent adsorption performance for CIP.The adsorption results showed that the adsorption process could be well interpreted by Temkin isothermal model and the pseudo second-order kinetics model.The maximal adsorption capacity of 20.01 mg·g^(-1)for CIP could be achieved under the optimal conditions optimized by response surface methodology(RSM).The inhibitory effect of co-existing ions on CIP adsorption were also discussed.The probable adsorption mechanism might be ascribed toπ-πinteractions,hydrogen bonding,electrostatic,and surface complexation.Regeneration tests showed that the obtained 3D porous material also possessed pronounced recyclability.The obtained(Zn-Al)LDHs/3D-rGO holds a great potential for removal of CIP from actual wastewater.展开更多
The demand for anisotropic aerogels with excellent comprehensive properties in cutting-edge fields such as aerospace is growing.Based on the above background,a novel heterocyclic para-aramid nanofiber/reduced graphene...The demand for anisotropic aerogels with excellent comprehensive properties in cutting-edge fields such as aerospace is growing.Based on the above background,a novel heterocyclic para-aramid nanofiber/reduced graphene oxide(HPAN/rGO)composite aerogel was prepared by combining electrospinning and unidirectional freeze-drying.The anisotropic HPAN/rGO composite aerogel exhibited a honeycomb morphology in the direction perpendicular to the growth of ice crystals,and a through-well structure of directed microchannels in the direction parallel to the temperature gradient.By varying the mass ratio of HPAN/rGO,a composite aerogel with an ultra-low density of 5.34-7.81 mg·cm^(-3) and an ultra-high porosity of 98%-99%was obtained.Benefiting from the anisotropic structure,the radial and axial thermal conductivities of HPAN/rGO-3 composite aerogel were 29.37 and 44.35 mW·m^(-1)·K^(-1),respectively.A combination of software simulation and experiments was used to analyze the effect of anisotropic structures on the thermal insulation properties of aerogels.Moreover,due to the intrinsic self-extinguishing properties of heterocyclic para-aramid and the protection of the graphene carbon layer,the composite aerogel also exhibits excellent flame retardancy properties,and its total heat release rate(THR)was only 5.8 kJ·g^(-1),which is far superior to many reported aerogels.Therefore,ultralight anisotropic HPAN/rGO composite aerogels with excellent high-temperature thermal insulation and flame retardancy properties have broad application prospects in complex environments such as aerospace.展开更多
Rechargeable batteries are essential energy storage devices that power portable devices and electrical vehicles throughout the wo rld.In general,it is thought that the electrochemical performance of recha rgeable batt...Rechargeable batteries are essential energy storage devices that power portable devices and electrical vehicles throughout the wo rld.In general,it is thought that the electrochemical performance of recha rgeable batteries is mostly determined by the electrodes within them and that the electrolyte plays a relatively passive role.However,ion transport and storage can be greatly influenced by the electrolyte solution structure,specifically,ion solvation within the bulk and ion desolvation across the electrode/electrolyte interfaces.Herein,we studied the role of the electrolyte as an active component of electrochemical energy storage devices.We found that with an appropriate electrolyte formulation,ion storage in disordered carbonaceous anode materials can occur spontaneously without externally supplied electrical energy.Reduced graphene oxide(RGO)in an ether-based electrolyte demonstrates'spontaneous'ion storage behaviors of adsorbing and inserting the solvated ions utilizing facilitated permeability and wettability of RGO,which results in Coulombic efficiency of~145%due to additional charging capacity of~180 mAh g^(-1)during electrochemical processes.The unexpected spontaneous ion storage behavior was extensively investigated using a combination of electrochemical analyses and diagnostics,advanced characterizations,and computational simulation.We believe the spontaneous ion storage behavior offers a new way to further improve the energy efficiency of practical rechargeable batteries.展开更多
Sodium-ion batteries have garnered significant attention as a cost-effective alternative to lithium-ion batteries due to the abundance and affordability of sodium precursors.However,the lack of suitable electrode mate...Sodium-ion batteries have garnered significant attention as a cost-effective alternative to lithium-ion batteries due to the abundance and affordability of sodium precursors.However,the lack of suitable electrode materials with both high capacity and excellent stability continues to hinder their practical viability.Herein,we couple lattice strain and sulfur deficiency effects in a tin monosulfide/reduced graphene oxide composite to enhance sodium storage performance.Experimental results and theoretical calculations reveal that the synergistic effects of lattice strain and sulfur vacancies in tin monosulfide promote rapid(de)intercalation near the surface/edge of the material,thereby enhancing its pseudocapacitive sodium storage properties.Consequently,the strained and defective tin monosulfide/reduced graphene oxide composite demonstrates a high reversible capacity of 511.82 mAh g^(-1) at 1 A g^(-1) and an outstanding rate capability of 450.60 mAh g^(-1) at 3 A g^(-1).This study offers an effective strategy for improving sodium storage performance through lattice strain and defect engineering.展开更多
A facile way was used to synthesize Cu2O/reduced graphene oxide （rGO） composites with octahedron-like morphology in aqueous solution without any surfactant. TEM images of the obtained Cu2O/rGOs reveal that the Cu2O ...A facile way was used to synthesize Cu2O/reduced graphene oxide （rGO） composites with octahedron-like morphology in aqueous solution without any surfactant. TEM images of the obtained Cu2O/rGOs reveal that the Cu2O particles and rGO distribute hierarchically and the primary Cu2O particles are encapsulated well in the graphene nanosheets. The electrochemical performance of Cu2O/rGOs is enhanced compared with bare Cu2O when they are employed as anode materials for lithium ion batteries. The Cu2O/rGO composites maintain a reversible capacity of 348.4 mA？h/g after 50 cycles at a current density of 100 mA/g. In addition, the composites retain 305.8 mA？h/g after 60 cycles at various current densities of 50, 100, 200, 400 and 800 mA/g.展开更多
An electrochemically reduced graphene oxide sample, ERGO_0.8v, was prepared by electrochemical reduction of graphene oxide （GO） at -0.8 V, which shows unique electrocatalytic activity toward tetracycline （TTC） det...An electrochemically reduced graphene oxide sample, ERGO_0.8v, was prepared by electrochemical reduction of graphene oxide （GO） at -0.8 V, which shows unique electrocatalytic activity toward tetracycline （TTC） detection compared to the ERGO-12v （GO applied to a negative potential of-1.2 V）, GO, chemically reduced GO （CRGO）-modified glassy carbon electrode （GC） and bare GC electrodes. The redox peaks of TTC on an ERGO-0.8v-modifled glass carbon electrode （GC/ERGO-0.8v） were within 0-0.5 V in a pH 3.0 buffer solution with the oxidation peak current correlating well with TTC concentration over a wide range from 0.1 to 160 mg/L Physical characterizations with Fourier transform infrared （FT-IR）, Raman, and X-ray photoelectron spectroscopies （XPS） demonstrated that the oxygen-containing functional groups on GO diminished after the electrochemical reduction at -0.8 V, yet still existed in large amounts, and the defect density changed as new sp2 domains were formed. These changes demonstrated that this adjustment in the number of oxygen-containing groups might be the main factor affecting the electrocatalytic behavior of ERGO. Additionally, the defect density and sp2 domains also exert a profound influence on this behavior. A possible mechanism for the TTC redox reaction at the GC/ERGO-0.8v electrode is also presented. This work suggests that the electrochemical reduction is an effective method to establish new catalytic activities of GO by setting appropriate parameters.展开更多
In order to ensure the operational reliability and infor-mation security of sophisticated electronic components and to protect human health,efficient electromagnetic interference(EMI)shielding materials are required t...In order to ensure the operational reliability and infor-mation security of sophisticated electronic components and to protect human health,efficient electromagnetic interference(EMI)shielding materials are required to attenuate electromagnetic wave energy.In this work,the cellulose solution is obtained by dissolving cotton through hydrogen bond driving self-assembly using sodium hydroxide(NaOH)/urea solution,and cellulose aerogels(CA)are prepared by gelation and freeze-drying.Then,the cellulose carbon aerogel@reduced graphene oxide aerogels(CCA@rGO)are prepared by vacuum impregnation,freeze-drying followed by thermal annealing,and finally,the CCA@rGO/polydimethylsiloxane(PDMS)EMI shielding composites are prepared by backfilling with PDMS.Owing to skin-core structure of CCA@rGO,the complete three-dimensional(3D)double-layer con-ductive network can be successfully constructed.When the loading of CCA@rGO is 3.05 wt%,CCA@rGO/PDMS EMI shielding composites have an excellent EMI shielding effectiveness(EMI SE)of 51 dB,which is 3.9 times higher than that of the co-blended CCA/rGO/PDMS EMI shielding composites(13 dB)with the same loading of fillers.At this time,the CCA@rGO/PDMS EMI shielding composites have excellent thermal stability(T_(HRI)of 178.3℃)and good thermal conductivity coefficient(λof 0.65 W m^(-1)K^(-1)).Excellent comprehensive performance makes CCA@rGO/PDMS EMI shielding composites great prospect for applications in lightweight,flexible EMI shielding composites.展开更多
A modified Hummer＇s method was adopted for the synthesis of graphene oxide（GO） and reduced graphene oxide（rGO）. It was revealed that the modified method is effective for the production of GO and rGO from graphite...A modified Hummer＇s method was adopted for the synthesis of graphene oxide（GO） and reduced graphene oxide（rGO）. It was revealed that the modified method is effective for the production of GO and rGO from graphite. Transmission electron microscopy（TEM） images of GO and rGO showed a sheet-like morphology. Because of the presence of oxygenated functional groups on the carbon surface, the interlayer spacing of the prepared GO was higher than that of rGO. The presence of ／OH and CO groups in the Fourier transform infrared spectra（FTIR） spectrum and G-mode and 2D-mode in Raman spectra confirmed the synthesis of GO and rGO. rGO（292.6 m2/g） showed higher surface area than that of GO（236.4 m2/g）. The prepared rGO was used as an adsorbent for benzene and toluene（model pollutants of volatile organic compounds（VOCs）） under dynamic adsorption/desorption conditions. rGO showed higher adsorption capacity and breakthrough times than GO. The adsorption capacity of rGO for benzene and toluene was 276.4 and 304.4 mg/g, respectively.Desorption experiments showed that the spent rGO can be successfully regenerated by heating at 150.0℃. Its excellent adsorption/desorption performance for benzene and toluene makes rGO a potential adsorbent for VOC adsorption.展开更多
The high-energy lithium/sulfur(Li/S) battery has become a very popular topic of research in recent years due to its high theoretical capacity of 1672 m Ah/g. However, the polysulfide shuttle effect remains of great co...The high-energy lithium/sulfur(Li/S) battery has become a very popular topic of research in recent years due to its high theoretical capacity of 1672 m Ah/g. However, the polysulfide shuttle effect remains of great concern with a great number of publications dedicated to its mitigation. In this contribution, a three-dimensional(3D) reduced graphene oxide/activated carbon(RGO/AC) film, synthesized by a simple hydrothermal method and convenient mechanical pressing, is sandwiched between the separator and the sulfur-based cathode, acting as a functional interlayer to capture and trap polysulfide species. Consequently, the Li/S cell with this interlayer shows an impressive initial discharge capacity of 1078 m Ah/g and a reversible capacity of 655 m Ah/g even after 100 cycles. The RGO/AC interlayer impedes the movement of polysulfide while providing unimpeded channels for lithium ion mass transfer. Therefore, the RGO/AC interlayer with a well-designed structure represents strong potential for high-performance Li/S batteries.展开更多
Recently,CoCO_(3)has attracted enormous attention as anodes for lithium-ion batteries(LIBs),benefiting from its high theoretical capacity and simple synthesis.However,the modest electronic conductivity and structural ...Recently,CoCO_(3)has attracted enormous attention as anodes for lithium-ion batteries(LIBs),benefiting from its high theoretical capacity and simple synthesis.However,the modest electronic conductivity and structural instability over cycling hinder its wider applications.To well address the intrinsic issues,we explored a precipitantfree hydrothermal methodology for mass production of spindle-like CoCO_(3)/reduced graphene oxide(S-CoCO_(3)/rGO)toward advanced LIBs as a hybrid anode.The dimethylformamide plays a significant role of"two birds(i.e.,solvent and precipitant)with one stone"in the formation of the S-CoCO_(3)/rGO,greatly improving its practical applicability.The purposeful introduction of rGO nanosheets as a two-dimensional flexible conductive network enhances the conductivity and stability of the S-CoCO_(3).It is the structural and compositional merits for LIBs that endow the S-CoCO3/rGO with remarkable lithium-storage performance in terms of enhanced interfacial storage capacity,high-rate reversible capacities(803 mAh·g^(-1)at 2.0 A·g^(-1))and long-duration capacity retention of 82.1%over 2000 consecutive cycles at 2.0 A·g^(-1).More significantly,the simple yet efficient avenue here promises enormous commercial prospect of the S-CoCO_(3)/rGO in next-generation LIBs.展开更多
The leakage of organic phase change materials(OPCMs)at temperatures above their melting point severely limits their large-scale application.The introduction of porous supports has been identified as an efficient leaka...The leakage of organic phase change materials(OPCMs)at temperatures above their melting point severely limits their large-scale application.The introduction of porous supports has been identified as an efficient leakageproofing method.In this study,a novel carbonized Cu-coated melamine foam(MF)/reduced graphene oxide(rGO)framework(MF/rGO/Cu-C)is constructed as a support for fabricating stabilized multifunctional OPCMs.MF serves as the supporting material,while rGO and Cu act as functional reinforcements.As a thermal energy storage material,polyethylene glycol(PEG)is encapsulated into MF/rGO/Cu-C through a vacuum-assisted impregnation method to obtain PEG@MF/rGO/Cu-C composite with excellent comprehensive performance.PEG@MF/rGO/Cu-C exhibits high phase change enthalpies of 148.3 J g^(-1)(melting)and 143.9 J g^(-1)(crystallization),corresponding to a high energy storage capability of 92.7%.Simultaneously,MF/rGO/Cu-C endues the composite with an enhanced thermal conductivity of 0.4621Wm^(-1) K^(-1),which increases by 463%compared to that of PEG@MF.Furthermore,PEG@MF/rGO/Cu-C displays great light-to-thermal and electric-to-thermal conversion capabilities,thermal cycle stability,light-tothermal cycle stability,and shape stability,showing promising application prospects in different aspects.展开更多
Objective This study was aimed to investigate the toxic effects of 3 nanomaterials, i.e. multi-walled carbon nanotubes （MWCNTs）, graphene oxide （GO）, and reduced graphene oxide （RGO）, on zebrafish embryos. Metho...Objective This study was aimed to investigate the toxic effects of 3 nanomaterials, i.e. multi-walled carbon nanotubes （MWCNTs）, graphene oxide （GO）, and reduced graphene oxide （RGO）, on zebrafish embryos. Methods The 2-h post-fertilization （hpf） zebrafish embryos were exposed to MWCNTs, GO, and RGO at different concentrations （1, 5, 10, 50, 100 mg/L） for 96 h. Afterwards, the effects of the 3 nanomateria on spontaneous movement, heart rate, hatching rate, length of larvae, mortality, and malformations Is were evaluated. Results Statistical analysis indicated that RGO significantly inhibited the hatching of zebrafish embryos. Furthermore, RGO and MWCNTs decreased the length of the hatched larvae at 96 hpf. No obvious morphological malformation or mortality was observed in the zebrafish embryos after exposure to the three nanomaterials. Conclusion MWCNTs, GO, and RGO were all toxic to zebrafish embryos to influence embryos hatching and larvae length. Although no obvious morphological malformation and mortality were observed in exposed zebrafish embryos, further studies on the toxicity of the three nanomaterials are still needed.展开更多
We previously combined reduced graphene oxide(rGO)with gelatin-methacryloyl(GelMA)and polycaprolactone(PCL)to create an rGO-GelMA-PCL nerve conduit and found that the conductivity and biocompatibility were improved.Ho...We previously combined reduced graphene oxide(rGO)with gelatin-methacryloyl(GelMA)and polycaprolactone(PCL)to create an rGO-GelMA-PCL nerve conduit and found that the conductivity and biocompatibility were improved.However,the rGO-GelMA-PCL nerve conduits differed greatly from autologous nerve transplants in their ability to promote the regeneration of injured peripheral nerves and axonal sprouting.Extracellular vesicles derived from bone marrow mesenchymal stem cells(BMSCs)can be loaded into rGO-GelMA-PCL nerve conduits for repair of rat sciatic nerve injury because they can promote angiogenesis at the injured site.In this study,12 weeks after surgery,sciatic nerve function was measured by electrophysiology and sciatic nerve function index,and myelin sheath and axon regeneration were observed by electron microscopy,immunohistochemistry,and immunofluorescence.The regeneration of microvessel was observed by immunofluorescence.Our results showed that rGO-GelMA-PCL nerve conduits loaded with BMSC-derived extracellular vesicles were superior to rGO-GelMA-PCL conduits alone in their ability to increase the number of newly formed vessels and axonal sprouts at the injury site as well as the recovery of neurological function.These findings indicate that rGO-GelMA-PCL nerve conduits loaded with BMSC-derived extracellular vesicles can promote peripheral nerve regeneration and neurological function recovery,and provide a new direction for the curation of peripheral nerve defect in the clinic.展开更多
It is critical to developing electrocatalysts with highly active and cost-effective for oxygen evolution to resolve environmental pollution and energy issues,in which FeNi-based nanomaterials hold a great promise.Here...It is critical to developing electrocatalysts with highly active and cost-effective for oxygen evolution to resolve environmental pollution and energy issues,in which FeNi-based nanomaterials hold a great promise.Herein,(Fe_(0.33 )Ni_(0.67))S_(2) and(Fe_(0.33 )Ni_(0.67))S_(2)/reduced graphene oxide(rGO)-x%(x=10,20) composites,which exhibited highly efficient oxygen evolution reaction(OER)electrocatalytic activity under alkaline conditions,were synthesized via a hydrothermal approach and following thermal treatment with sulfur powders.Benefiting from the integrated structure of(Fe_(0.33 )Ni_(0.67))S_(2)and support of conductive graphene backbones,(Fe_(0.33 )Ni_(0.67))S_(2)/rGO-20%electrocatalyst showed the best OER activity with an overpotential of 172 mV at 10 mA·cm^(-2)and Tafel slopes of 45 mV·decade^(-1).The composition,phase,and surface structure of the catalyst were characterized before and after OER reaction.The results indicated that crystal phase of the catalyst was reconstructed to the amorphous crystalline features after OER,with oxidation of iron-nickel sulfide and appearance of Ni-Fe oxo/hydroxide species,which may play a crucial role in the high OER performance as the catalytic-active.Moreover,in a two-electrode system towards overall water splitting with(Fe_(0.33 )Ni_(0.67))S_(2)/rGO-20%/NF and Pt/C/NF as the anode and cathode,respectively,the catalysts exhibited excellent catalytic performance with the voltage of only 1.42 V at 10 mA·cm^(-2).展开更多
Considering the serious electromagnetic wave(EMW)pollution problems and complex application condition,there is a pressing need to amalgamate multiple functionalities within a single substance.However,the effective int...Considering the serious electromagnetic wave(EMW)pollution problems and complex application condition,there is a pressing need to amalgamate multiple functionalities within a single substance.However,the effective integration of diverse functions into designed EMW absorption materials still faces the huge challenges.Herein,reduced graphene oxide/carbon foams(RGO/CFs)with two-dimensional/three-dimensional(2D/3D)van der Waals(vdWs)heterostructures were meticulously engineered and synthesized utilizing an efficient methodology involving freeze-drying,immersing absorption,secondary freeze-drying,followed by carbonization treatment.Thanks to their excellent linkage effect of amplified dielectric loss and optimized impedance matching,the designed 2D/3D RGO/CFs vdWs heterostructures demonstrated commendable EMW absorption performances,achieving a broad absorption bandwidth of 6.2 GHz and a reflection loss of-50.58 dB with the low matching thicknesses.Furthermore,the obtained 2D/3D RGO/CFs vdWs heterostructures also displayed the significant radar stealth properties,good corrosion resistance performances as well as outstanding thermal insulation capabilities,displaying the great potential in complex and variable environments.Accordingly,this work not only demonstrated a straightforward method for fabricating 2D/3D vdWs heterostructures,but also outlined a powerful mixeddimensional assembly strategy for engineering multifunctional foams for electromagnetic protection,aerospace and other complex conditions.展开更多
Fabrication of graphene/ceramic composites commonly requires a high-temperature sintering step with long times as well as a vacuum or inert atmosphere,which not only results in property degradation but also significan...Fabrication of graphene/ceramic composites commonly requires a high-temperature sintering step with long times as well as a vacuum or inert atmosphere,which not only results in property degradation but also significant equipment complexity and manufacturing costs.In this work,the ambient flash sintering behavior of reduced graphene oxide/3 mol% yttria-stabilized ZrO_(2)(rGO/3 YSZ) composites utilizing rGO as both a composite component and a conductive additive is reported.When the sintering condition is carefully optimized,a dense and conductive composite can be achieved at room temperature and in the air within 20 s.The role of the rGO in the FS of the rGO/3 YSZ composites is elucidated,especially with the assistance of a separate investigation on the thermal runaway behavior of the rGO.The work suggests a promising fabrication route for rGO/ceramic composites where the vacuum and furnace are not needed,which is of interest in terms of simplifying the fabrication equipment for energy and cost savings.展开更多
基金supported by Korea Electrotechnology Research Institute(KERI)Primary research program through the National Research Council of Science&Technology(NST)funded by the Ministry of Science and ICT(MSIT)(No.25A01015)by the Technology Innovation Program(20019091)funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea)by the National Research Council of Science&Technology(NST)grant from the Korea government(MSIT)(No.GTL24012-000).
文摘Carbon coatings for silicon(Si)-based anode materials are essential for designing high-performance Li-ion batteries(LIBs).The coatings prevent direct contact with the electrolyte and enhance anode performance.However,conventional carbon coatings are limited by their volume expansion and structural degradation,which lead to capacity fading and reduced durability.This study introduces a scalable and practical one-step carbon-coating strategy for directly coating silicon suboxide(SiO_(x))-based materials using aqueous quasi-defect-free reduced graphene oxide(QrGO)without post-treatment,unlike conventional graphene oxide(GO)-based coating methods.This simple process enables uniform encapsulation with QrGO for a highly adhesive and conductive coating.The QrGO-based composite anode material has several advantages,including reduced cracking due to volume expansion and enhanced charge carrier transport,as well as an increased Si content of 20 wt.%compared to the 5 wt.%in typical commercial Si-based active materials.In particular,the capacity retention of the QrGO-coated Si electrodes dramatically increases at high C-rate.The full cell exhibited long-term stability and capacity that were twice that of commercial SiO_(x)-based cells.Therefore,the QrGO-based one-step coating process represents a scalable,transformative,and commercially viable strategy for developing high-performance LIBs.
基金supported by the National Natural Science Foundation of China(No.61904073)Spring City Plan-Special Program for Young Talents(No.K202005007)+4 种基金Yunnan Talents Support Plan for Yong Talents(No.XDYC-QNRC-20220482)Yunnan Local Colleges Applied Basic Research Projects(No.202101BA070001-138)Scientific Research Fund of Yunnan Education Department(No.2023Y0883)Frontier Research Team of Kunming University 2023Key Laboratory of Artificial Microstructures in Yunnan Higher Education。
文摘Silicon-air batteries(SABs),a new type of semiconductor air battery,have a high energy density.However,some side reactions in SABs cause Si anodes to be covered by a passivation layer to prevent continuous discharge,and the anode utilization rate is low.In this work,reduced graphene oxide(RGO)fabricated via high-temperature annealing or L-ascorbic acid(L.AA)reduction was first used to obtain Si nanowires/RGO-1000(Si NWs/RGO-1000)and Si nanowires/RGO-L.AA(Si NWs/RGO-L.AA)composite anodes for SABs.It was found that RGO suppressed the passivation and self-corrosion reactions and that SABs using Si NWs/RGO-L.AA as the anode can discharge for more than 700 h,breaking the previous performance of SABs,and that the specific capacity was increased by 90.8%compared to bare Si.This work provides a new solution for the design of high specific capacity SABs with nanostructures and anode protective layers.
基金supported by the following funds:The National Natural Science Foundation of China(Nos.52275393,51935014,and 82072084)Jiangxi Provincial Natural Science Foundation of China(No.20224ACB204013)+2 种基金The Project of State Key Laboratory of Precision Manufacturing for Extreme Service Performancethe National Key Research and Development Program of China(No.2023YFB4605800)the Independent Exploration and Innovation Project of Central South University(No.1053320221707).
文摘Fast electron-hole recombination issues during titanium dioxide(TiO_(2))photocatalysis limit its application in preventing bacterial infection during bone defect repair.In this study,TiO_(2)@reduced graphene oxide(rGO)composites were synthesized using a hydrothermal method in which rGO,which possesses very high electrical conductivity,promotes the separation of photoelectron-hole pairs of TiO_(2),thus improving the efficiency of photocatalytic production of reactive oxygen species(ROS).Subsequently,TiO_(2)@rGO composites were introduced into poly-L-lactic acid(PLLA)to prepare bone scaffolds with photocatalytic antibacterial function via selective laser sintering.The results showed that TiO_(2)grew on the surface of rGO and formed a covalent bond connection(Ti-O-C)with rGO.A decreased electrochemical impedance of TiO_(2)@rGO composites was observed,and the transient photocurrent intensity increased from 0.05 to 0.5μA/cm^(2).Analysis of electron spin resonance found that the photocatalytic products of TiO_(2)were·OH and·O^(2-),two kinds of ROS capable of killing bacteria via disrupting the structure of the bacterial membrane in vitro.Antibacterial experiments showed that the PLLA/TiO_(2)@rGO scaffolds had good antibacterial properties against Escherichia coli and Staphylococcus aureus.Finally,we report that these scaffolds exhibited both enhanced mechanical properties due to the addition of TiO_(2)@rGO as a reinforcement material and good biocompatibility during cell proliferation.
基金support of the Key Science Research Project in Colleges and Universities of Anhui Province,China(No.2022AH050813)the Medical Special Cultivation Project of Anhui University of Science and Technology,China(No.YZ2023H2A002).
文摘Carbon-based foams with a three-dimensional structure can serve as a lightweight template for the rational design and control-lable preparation of metal oxide/carbon-based composite microwave absorption materials.In this study,a flake-like nickel cobaltate/re-duced graphene oxide/melamine-derived carbon foam(FNC/RGO/MDCF)was successfully fabricated through a combination of solvo-thermal treatment and high-temperature pyrolysis.Results indicated that RGO was evenly distributed in the MDCF skeleton,providing ef-fective support for the load growth of FNC on its surface.Sample S3,the FNC/RGO/MDCF composite prepared by solvothermal method for 16 h,exhibited a minimum reflection loss(RL_(min))of-66.44 dB at a thickness of 2.29 mm.When the thickness was reduced to 1.50 mm,the optimal effective absorption bandwidth was 3.84 GHz.Analysis of the absorption mechanism of FNC/RGO/MDCF revealed that its excellent absorption performance was primarily attributed to the combined effects of conduction loss,multiple reflection,scattering,in-terface polarization,and dipole polarization.
基金support from Basic research project of Education Department of Liaoning Province(LJKZ0256)Special Fund for Basic Scientific Research of Liaoning Province(LJKZSYLUGX027).
文摘The indiscriminate use and disposal of ciprofloxacin(CIP)have led to its detection in water globally,which pose a huge risk to public health and water environment.Herein,(Zn-Al)LDHs modified 3D reduced graphene oxide nanocomposite((Zn-Al)LDHs/3D-rGO)was synthesized through a feasible onepot hydrothermal method for CIP removal.The highly distributed(Zn-Al)LDHs flakes on the surface of 3D-rGO endow the resulted(Zn-Al)LDHs/3D-rGO with an excellent adsorption performance for CIP.The adsorption results showed that the adsorption process could be well interpreted by Temkin isothermal model and the pseudo second-order kinetics model.The maximal adsorption capacity of 20.01 mg·g^(-1)for CIP could be achieved under the optimal conditions optimized by response surface methodology(RSM).The inhibitory effect of co-existing ions on CIP adsorption were also discussed.The probable adsorption mechanism might be ascribed toπ-πinteractions,hydrogen bonding,electrostatic,and surface complexation.Regeneration tests showed that the obtained 3D porous material also possessed pronounced recyclability.The obtained(Zn-Al)LDHs/3D-rGO holds a great potential for removal of CIP from actual wastewater.
基金supported by the National Key R&D Program of China(No.2021YFB3700103).
文摘The demand for anisotropic aerogels with excellent comprehensive properties in cutting-edge fields such as aerospace is growing.Based on the above background,a novel heterocyclic para-aramid nanofiber/reduced graphene oxide(HPAN/rGO)composite aerogel was prepared by combining electrospinning and unidirectional freeze-drying.The anisotropic HPAN/rGO composite aerogel exhibited a honeycomb morphology in the direction perpendicular to the growth of ice crystals,and a through-well structure of directed microchannels in the direction parallel to the temperature gradient.By varying the mass ratio of HPAN/rGO,a composite aerogel with an ultra-low density of 5.34-7.81 mg·cm^(-3) and an ultra-high porosity of 98%-99%was obtained.Benefiting from the anisotropic structure,the radial and axial thermal conductivities of HPAN/rGO-3 composite aerogel were 29.37 and 44.35 mW·m^(-1)·K^(-1),respectively.A combination of software simulation and experiments was used to analyze the effect of anisotropic structures on the thermal insulation properties of aerogels.Moreover,due to the intrinsic self-extinguishing properties of heterocyclic para-aramid and the protection of the graphene carbon layer,the composite aerogel also exhibits excellent flame retardancy properties,and its total heat release rate(THR)was only 5.8 kJ·g^(-1),which is far superior to many reported aerogels.Therefore,ultralight anisotropic HPAN/rGO composite aerogels with excellent high-temperature thermal insulation and flame retardancy properties have broad application prospects in complex environments such as aerospace.
基金supported by the faculty research fund of Sejong Universityfunding from the National Research Foundation of Korea(NRF)under grant number NRF-2022R1F1A1071444+2 种基金funding from NRF under grant numbers NRF-2022R1A2B5B03001781Funding provided by the Department of Energy Office of Energy EfficiencyRenewable Energy Vehicles Technology Office。
文摘Rechargeable batteries are essential energy storage devices that power portable devices and electrical vehicles throughout the wo rld.In general,it is thought that the electrochemical performance of recha rgeable batteries is mostly determined by the electrodes within them and that the electrolyte plays a relatively passive role.However,ion transport and storage can be greatly influenced by the electrolyte solution structure,specifically,ion solvation within the bulk and ion desolvation across the electrode/electrolyte interfaces.Herein,we studied the role of the electrolyte as an active component of electrochemical energy storage devices.We found that with an appropriate electrolyte formulation,ion storage in disordered carbonaceous anode materials can occur spontaneously without externally supplied electrical energy.Reduced graphene oxide(RGO)in an ether-based electrolyte demonstrates'spontaneous'ion storage behaviors of adsorbing and inserting the solvated ions utilizing facilitated permeability and wettability of RGO,which results in Coulombic efficiency of~145%due to additional charging capacity of~180 mAh g^(-1)during electrochemical processes.The unexpected spontaneous ion storage behavior was extensively investigated using a combination of electrochemical analyses and diagnostics,advanced characterizations,and computational simulation.We believe the spontaneous ion storage behavior offers a new way to further improve the energy efficiency of practical rechargeable batteries.
基金supported by the National Natural Science Foundation of China(no.22109023,no.22179022,and no.22209027)the Youth Innovation Fund of Fujian Province(no.2021J05043 and no.2022J05046)+5 种基金the National Key Research and Development Program of China(2023YFC3906300)the FuXiaQuan National Independent Innovation Demonstration Zone Collaborative Innovation Platform(no.2022-P-027)the·“Hundred Talents·Plan”of Fujian Provincethe“Top Young Talents of Young Eagle”Program of Fujian Provincethe Award Program for Fujian Minjiang Scholar Professorshipthe Talent Fund Program of Fujian Normal University.
文摘Sodium-ion batteries have garnered significant attention as a cost-effective alternative to lithium-ion batteries due to the abundance and affordability of sodium precursors.However,the lack of suitable electrode materials with both high capacity and excellent stability continues to hinder their practical viability.Herein,we couple lattice strain and sulfur deficiency effects in a tin monosulfide/reduced graphene oxide composite to enhance sodium storage performance.Experimental results and theoretical calculations reveal that the synergistic effects of lattice strain and sulfur vacancies in tin monosulfide promote rapid(de)intercalation near the surface/edge of the material,thereby enhancing its pseudocapacitive sodium storage properties.Consequently,the strained and defective tin monosulfide/reduced graphene oxide composite demonstrates a high reversible capacity of 511.82 mAh g^(-1) at 1 A g^(-1) and an outstanding rate capability of 450.60 mAh g^(-1) at 3 A g^(-1).This study offers an effective strategy for improving sodium storage performance through lattice strain and defect engineering.
基金Project (2014CB643406) supported by the National Basic Research Program of ChinaProject (2011FJ1005) supported by Major Special Project of Science and Technology of Hunan Province,China
文摘A facile way was used to synthesize Cu2O/reduced graphene oxide （rGO） composites with octahedron-like morphology in aqueous solution without any surfactant. TEM images of the obtained Cu2O/rGOs reveal that the Cu2O particles and rGO distribute hierarchically and the primary Cu2O particles are encapsulated well in the graphene nanosheets. The electrochemical performance of Cu2O/rGOs is enhanced compared with bare Cu2O when they are employed as anode materials for lithium ion batteries. The Cu2O/rGO composites maintain a reversible capacity of 348.4 mA？h/g after 50 cycles at a current density of 100 mA/g. In addition, the composites retain 305.8 mA？h/g after 60 cycles at various current densities of 50, 100, 200, 400 and 800 mA/g.
基金supported by the National Natural Science Foundation of China(21007033)the Fundamental Research Funds of Shandong University(2015JC017)~~
文摘An electrochemically reduced graphene oxide sample, ERGO_0.8v, was prepared by electrochemical reduction of graphene oxide （GO） at -0.8 V, which shows unique electrocatalytic activity toward tetracycline （TTC） detection compared to the ERGO-12v （GO applied to a negative potential of-1.2 V）, GO, chemically reduced GO （CRGO）-modified glassy carbon electrode （GC） and bare GC electrodes. The redox peaks of TTC on an ERGO-0.8v-modifled glass carbon electrode （GC/ERGO-0.8v） were within 0-0.5 V in a pH 3.0 buffer solution with the oxidation peak current correlating well with TTC concentration over a wide range from 0.1 to 160 mg/L Physical characterizations with Fourier transform infrared （FT-IR）, Raman, and X-ray photoelectron spectroscopies （XPS） demonstrated that the oxygen-containing functional groups on GO diminished after the electrochemical reduction at -0.8 V, yet still existed in large amounts, and the defect density changed as new sp2 domains were formed. These changes demonstrated that this adjustment in the number of oxygen-containing groups might be the main factor affecting the electrocatalytic behavior of ERGO. Additionally, the defect density and sp2 domains also exert a profound influence on this behavior. A possible mechanism for the TTC redox reaction at the GC/ERGO-0.8v electrode is also presented. This work suggests that the electrochemical reduction is an effective method to establish new catalytic activities of GO by setting appropriate parameters.
基金the Foundation of National Natural Science Foundation of China(51773169 and 51973173)the Natural Science Basic Research Plan for Distinguished Young Scholars in Shaanxi Province of China(2019JC-11)+2 种基金the Natural Science Basic Research Plan in Shaanxi Province of China(2020JQ-164)Y.Q.Guo thanks the Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University(CX202055)Polymer Electromagnetic Functional Materials Innovation Team of Shaanxi Sanqin Scholars.
文摘In order to ensure the operational reliability and infor-mation security of sophisticated electronic components and to protect human health,efficient electromagnetic interference(EMI)shielding materials are required to attenuate electromagnetic wave energy.In this work,the cellulose solution is obtained by dissolving cotton through hydrogen bond driving self-assembly using sodium hydroxide(NaOH)/urea solution,and cellulose aerogels(CA)are prepared by gelation and freeze-drying.Then,the cellulose carbon aerogel@reduced graphene oxide aerogels(CCA@rGO)are prepared by vacuum impregnation,freeze-drying followed by thermal annealing,and finally,the CCA@rGO/polydimethylsiloxane(PDMS)EMI shielding composites are prepared by backfilling with PDMS.Owing to skin-core structure of CCA@rGO,the complete three-dimensional(3D)double-layer con-ductive network can be successfully constructed.When the loading of CCA@rGO is 3.05 wt%,CCA@rGO/PDMS EMI shielding composites have an excellent EMI shielding effectiveness(EMI SE)of 51 dB,which is 3.9 times higher than that of the co-blended CCA/rGO/PDMS EMI shielding composites(13 dB)with the same loading of fillers.At this time,the CCA@rGO/PDMS EMI shielding composites have excellent thermal stability(T_(HRI)of 178.3℃)and good thermal conductivity coefficient(λof 0.65 W m^(-1)K^(-1)).Excellent comprehensive performance makes CCA@rGO/PDMS EMI shielding composites great prospect for applications in lightweight,flexible EMI shielding composites.
基金financially supported by the China Postdoctoral Science Foundation(2016M592496)National Natural Science Foundation of China(Nos.91645119,21207039,U1201231,51378218,51108187 and 50978103)+2 种基金the Fundamental Research Funds for the Central Universities(Nos.2017BQ053 and 2017BQ055)Natural Science Foundation of Guangdong Province,China(Grant No.2014A030310431)Guangzhou Science and Technology Plan(201607010095)
文摘A modified Hummer＇s method was adopted for the synthesis of graphene oxide（GO） and reduced graphene oxide（rGO）. It was revealed that the modified method is effective for the production of GO and rGO from graphite. Transmission electron microscopy（TEM） images of GO and rGO showed a sheet-like morphology. Because of the presence of oxygenated functional groups on the carbon surface, the interlayer spacing of the prepared GO was higher than that of rGO. The presence of ／OH and CO groups in the Fourier transform infrared spectra（FTIR） spectrum and G-mode and 2D-mode in Raman spectra confirmed the synthesis of GO and rGO. rGO（292.6 m2/g） showed higher surface area than that of GO（236.4 m2/g）. The prepared rGO was used as an adsorbent for benzene and toluene（model pollutants of volatile organic compounds（VOCs）） under dynamic adsorption/desorption conditions. rGO showed higher adsorption capacity and breakthrough times than GO. The adsorption capacity of rGO for benzene and toluene was 276.4 and 304.4 mg/g, respectively.Desorption experiments showed that the spent rGO can be successfully regenerated by heating at 150.0℃. Its excellent adsorption/desorption performance for benzene and toluene makes rGO a potential adsorbent for VOC adsorption.
基金financial support from the National Natural Science Foundation of China(grant no.21406052the Program for the Outstanding Young Talents of Hebei Province(grant no.BJ2014010)the Scientific Research Foundation for Selected Overseas Chinese Scholars,Ministry of Human Resources and Social Security of China(grant no.CG2015003002)
文摘The high-energy lithium/sulfur(Li/S) battery has become a very popular topic of research in recent years due to its high theoretical capacity of 1672 m Ah/g. However, the polysulfide shuttle effect remains of great concern with a great number of publications dedicated to its mitigation. In this contribution, a three-dimensional(3D) reduced graphene oxide/activated carbon(RGO/AC) film, synthesized by a simple hydrothermal method and convenient mechanical pressing, is sandwiched between the separator and the sulfur-based cathode, acting as a functional interlayer to capture and trap polysulfide species. Consequently, the Li/S cell with this interlayer shows an impressive initial discharge capacity of 1078 m Ah/g and a reversible capacity of 655 m Ah/g even after 100 cycles. The RGO/AC interlayer impedes the movement of polysulfide while providing unimpeded channels for lithium ion mass transfer. Therefore, the RGO/AC interlayer with a well-designed structure represents strong potential for high-performance Li/S batteries.
基金financially supported by the National Natural Science Foundation of China(Nos.51772127 and 51772131)the Taishan Scholars(No.ts201712050)+3 种基金the Major Program of Shandong Province Natural Science Foundation(No.ZR2018ZB0317)the Natural Science Doctoral Foundation ofShandong Province(No.ZR2019BEM038)the Natural Science Doctoral Foundation of the University of Jinan(No.XBS1830)the Collaborative Innovation Center of Technology and Equipment for Biological Diagnosis and Therapy in Universities of Shandong。
文摘Recently,CoCO_(3)has attracted enormous attention as anodes for lithium-ion batteries(LIBs),benefiting from its high theoretical capacity and simple synthesis.However,the modest electronic conductivity and structural instability over cycling hinder its wider applications.To well address the intrinsic issues,we explored a precipitantfree hydrothermal methodology for mass production of spindle-like CoCO_(3)/reduced graphene oxide(S-CoCO_(3)/rGO)toward advanced LIBs as a hybrid anode.The dimethylformamide plays a significant role of"two birds(i.e.,solvent and precipitant)with one stone"in the formation of the S-CoCO_(3)/rGO,greatly improving its practical applicability.The purposeful introduction of rGO nanosheets as a two-dimensional flexible conductive network enhances the conductivity and stability of the S-CoCO_(3).It is the structural and compositional merits for LIBs that endow the S-CoCO3/rGO with remarkable lithium-storage performance in terms of enhanced interfacial storage capacity,high-rate reversible capacities(803 mAh·g^(-1)at 2.0 A·g^(-1))and long-duration capacity retention of 82.1%over 2000 consecutive cycles at 2.0 A·g^(-1).More significantly,the simple yet efficient avenue here promises enormous commercial prospect of the S-CoCO_(3)/rGO in next-generation LIBs.
基金National Natural Science Foundation of China,Grant/Award Numbers:51861005,52071092,U20A20237Guangxi Natural Science Foundation,Grant/Award Numbers:2019GXNSFDA245023,2019GXNSFGA245005,2020GXNSFGA297004,2021GXNSFFA196002Guangxi Bagui Scholar Foundation。
文摘The leakage of organic phase change materials(OPCMs)at temperatures above their melting point severely limits their large-scale application.The introduction of porous supports has been identified as an efficient leakageproofing method.In this study,a novel carbonized Cu-coated melamine foam(MF)/reduced graphene oxide(rGO)framework(MF/rGO/Cu-C)is constructed as a support for fabricating stabilized multifunctional OPCMs.MF serves as the supporting material,while rGO and Cu act as functional reinforcements.As a thermal energy storage material,polyethylene glycol(PEG)is encapsulated into MF/rGO/Cu-C through a vacuum-assisted impregnation method to obtain PEG@MF/rGO/Cu-C composite with excellent comprehensive performance.PEG@MF/rGO/Cu-C exhibits high phase change enthalpies of 148.3 J g^(-1)(melting)and 143.9 J g^(-1)(crystallization),corresponding to a high energy storage capability of 92.7%.Simultaneously,MF/rGO/Cu-C endues the composite with an enhanced thermal conductivity of 0.4621Wm^(-1) K^(-1),which increases by 463%compared to that of PEG@MF.Furthermore,PEG@MF/rGO/Cu-C displays great light-to-thermal and electric-to-thermal conversion capabilities,thermal cycle stability,light-tothermal cycle stability,and shape stability,showing promising application prospects in different aspects.
基金supported by the Specialized Research Fund for the Doctoral Program of Higher Education(200800191013)the Fundamental Research Funds for the Central Universities
文摘Objective This study was aimed to investigate the toxic effects of 3 nanomaterials, i.e. multi-walled carbon nanotubes （MWCNTs）, graphene oxide （GO）, and reduced graphene oxide （RGO）, on zebrafish embryos. Methods The 2-h post-fertilization （hpf） zebrafish embryos were exposed to MWCNTs, GO, and RGO at different concentrations （1, 5, 10, 50, 100 mg/L） for 96 h. Afterwards, the effects of the 3 nanomateria on spontaneous movement, heart rate, hatching rate, length of larvae, mortality, and malformations Is were evaluated. Results Statistical analysis indicated that RGO significantly inhibited the hatching of zebrafish embryos. Furthermore, RGO and MWCNTs decreased the length of the hatched larvae at 96 hpf. No obvious morphological malformation or mortality was observed in the zebrafish embryos after exposure to the three nanomaterials. Conclusion MWCNTs, GO, and RGO were all toxic to zebrafish embryos to influence embryos hatching and larvae length. Although no obvious morphological malformation and mortality were observed in exposed zebrafish embryos, further studies on the toxicity of the three nanomaterials are still needed.
基金supported by the National Natural Science Foundation of China, No. 31671248the Natural Science Foundation of Beijing, No. 7222198 (both to NH)
文摘We previously combined reduced graphene oxide(rGO)with gelatin-methacryloyl(GelMA)and polycaprolactone(PCL)to create an rGO-GelMA-PCL nerve conduit and found that the conductivity and biocompatibility were improved.However,the rGO-GelMA-PCL nerve conduits differed greatly from autologous nerve transplants in their ability to promote the regeneration of injured peripheral nerves and axonal sprouting.Extracellular vesicles derived from bone marrow mesenchymal stem cells(BMSCs)can be loaded into rGO-GelMA-PCL nerve conduits for repair of rat sciatic nerve injury because they can promote angiogenesis at the injured site.In this study,12 weeks after surgery,sciatic nerve function was measured by electrophysiology and sciatic nerve function index,and myelin sheath and axon regeneration were observed by electron microscopy,immunohistochemistry,and immunofluorescence.The regeneration of microvessel was observed by immunofluorescence.Our results showed that rGO-GelMA-PCL nerve conduits loaded with BMSC-derived extracellular vesicles were superior to rGO-GelMA-PCL conduits alone in their ability to increase the number of newly formed vessels and axonal sprouts at the injury site as well as the recovery of neurological function.These findings indicate that rGO-GelMA-PCL nerve conduits loaded with BMSC-derived extracellular vesicles can promote peripheral nerve regeneration and neurological function recovery,and provide a new direction for the curation of peripheral nerve defect in the clinic.
基金financially supported by the National Natural Science Foundation of China (No.52002363)the Aeronautical Science Foundation of China (No.2020Z054025002)+1 种基金Shandong Provincial Natural Science Foundation Project (No. ZR2021ME083)the Undergraduate Innovation Training Program Fund of Liaocheng University (No.cxcy2021108)
文摘It is critical to developing electrocatalysts with highly active and cost-effective for oxygen evolution to resolve environmental pollution and energy issues,in which FeNi-based nanomaterials hold a great promise.Herein,(Fe_(0.33 )Ni_(0.67))S_(2) and(Fe_(0.33 )Ni_(0.67))S_(2)/reduced graphene oxide(rGO)-x%(x=10,20) composites,which exhibited highly efficient oxygen evolution reaction(OER)electrocatalytic activity under alkaline conditions,were synthesized via a hydrothermal approach and following thermal treatment with sulfur powders.Benefiting from the integrated structure of(Fe_(0.33 )Ni_(0.67))S_(2)and support of conductive graphene backbones,(Fe_(0.33 )Ni_(0.67))S_(2)/rGO-20%electrocatalyst showed the best OER activity with an overpotential of 172 mV at 10 mA·cm^(-2)and Tafel slopes of 45 mV·decade^(-1).The composition,phase,and surface structure of the catalyst were characterized before and after OER reaction.The results indicated that crystal phase of the catalyst was reconstructed to the amorphous crystalline features after OER,with oxidation of iron-nickel sulfide and appearance of Ni-Fe oxo/hydroxide species,which may play a crucial role in the high OER performance as the catalytic-active.Moreover,in a two-electrode system towards overall water splitting with(Fe_(0.33 )Ni_(0.67))S_(2)/rGO-20%/NF and Pt/C/NF as the anode and cathode,respectively,the catalysts exhibited excellent catalytic performance with the voltage of only 1.42 V at 10 mA·cm^(-2).
基金provided by Guizhou Provincial Science and Technology Projects for Platform and Talent Team Plan(GCC[2023]007)Fok Ying Tung Education Foundation(171095)National Natural Science Foundation of China(11964006).
文摘Considering the serious electromagnetic wave(EMW)pollution problems and complex application condition,there is a pressing need to amalgamate multiple functionalities within a single substance.However,the effective integration of diverse functions into designed EMW absorption materials still faces the huge challenges.Herein,reduced graphene oxide/carbon foams(RGO/CFs)with two-dimensional/three-dimensional(2D/3D)van der Waals(vdWs)heterostructures were meticulously engineered and synthesized utilizing an efficient methodology involving freeze-drying,immersing absorption,secondary freeze-drying,followed by carbonization treatment.Thanks to their excellent linkage effect of amplified dielectric loss and optimized impedance matching,the designed 2D/3D RGO/CFs vdWs heterostructures demonstrated commendable EMW absorption performances,achieving a broad absorption bandwidth of 6.2 GHz and a reflection loss of-50.58 dB with the low matching thicknesses.Furthermore,the obtained 2D/3D RGO/CFs vdWs heterostructures also displayed the significant radar stealth properties,good corrosion resistance performances as well as outstanding thermal insulation capabilities,displaying the great potential in complex and variable environments.Accordingly,this work not only demonstrated a straightforward method for fabricating 2D/3D vdWs heterostructures,but also outlined a powerful mixeddimensional assembly strategy for engineering multifunctional foams for electromagnetic protection,aerospace and other complex conditions.
基金supported by Shanghai Pujiang Program[No.18PJ1406500]the National Natural Science Foundation of China[No.51902197]the Start-up Foundation for the Youth Scholars of Shanghai Jiao Tong University[No.18×100040024]。
文摘Fabrication of graphene/ceramic composites commonly requires a high-temperature sintering step with long times as well as a vacuum or inert atmosphere,which not only results in property degradation but also significant equipment complexity and manufacturing costs.In this work,the ambient flash sintering behavior of reduced graphene oxide/3 mol% yttria-stabilized ZrO_(2)(rGO/3 YSZ) composites utilizing rGO as both a composite component and a conductive additive is reported.When the sintering condition is carefully optimized,a dense and conductive composite can be achieved at room temperature and in the air within 20 s.The role of the rGO in the FS of the rGO/3 YSZ composites is elucidated,especially with the assistance of a separate investigation on the thermal runaway behavior of the rGO.The work suggests a promising fabrication route for rGO/ceramic composites where the vacuum and furnace are not needed,which is of interest in terms of simplifying the fabrication equipment for energy and cost savings.
