The poor corrosion and wear resistances of Mg alloys seriously limit their potential applications in various industries.The conventional epoxy coating easily forms many intrinsic defects during the solidification proc...The poor corrosion and wear resistances of Mg alloys seriously limit their potential applications in various industries.The conventional epoxy coating easily forms many intrinsic defects during the solidification process,which cannot provide sufficient protection.In the current study,we design a double-layer epoxy composite coating on Mg alloy with enhanced anti-corrosion/wear properties,via the spin-assisted assembly technique.The outer layer is functionalized graphene(FG)in waterborne epoxy resin(WEP)and the inner layer is Ce-based conversion(Ce)film.The FG sheets can be homogeneously dispersed within the epoxy matrix to fill the intrinsic defects and improve the barrier capability.The Ce film connects the outer layer with the substrate,showing the transition effect.The corrosion rate of Ce/WEP/FG composite coating is 2131 times lower than that of bare Mg alloy,and the wear rate is decreased by~90%.The improved corrosion resistance is attributed to the labyrinth effect(hindering the penetration of corrosive medium)and the obstruction of galvanic coupling behavior.The synergistic effect derived from the FG sheet and blocking layer exhibits great potential in realizing the improvement of multi-functional integration,which will open up a new avenue for the development of novel composite protection coatings of Mg alloys.展开更多
The effect of functionalized graphene on the growth and development of Vicia faba L.was investigated by analyzing its impact on the composition and diversity of the microbial community in rhizosphere peat soil.Seedlin...The effect of functionalized graphene on the growth and development of Vicia faba L.was investigated by analyzing its impact on the composition and diversity of the microbial community in rhizosphere peat soil.Seedlings of V.faba planted in this peat soil were treated with either distilled water(CK)or 25 mg·L^(−1)(G25)of functionalized graphene solution.Results showed that the height and root length of V.faba seedlings in the G25 group were significantly larger than those in CK group.The microbial com-munity was analyzed by amplifying and sequencing the 16S rRNA gene V_(3)-V_(4) region of bacteria and internal transcribed spacer re-gion of fungi in rhizosphere soil using Illumina MiSeq technology.Alpha and beta diversity analysis indicated that functionalized graphene increased the richness and diversity of bacteria and fungi in the V.faba rhizosphere peat soil.The abundances of three ni-trogen cycling-related bacteria,Hydrogenophaga,Sphingomonas and Nitrosomonadaceae,were also altered after treatment with the functionalized graphene.The relative abundance of Basilicum,related to soil phosphorus solubilization,decreased in the fungal com-munity,while the relative abundance of Clonostachys and Dimorphospora,which exhibited strong biological control over numerous fungal plant pathogens,nematodes and insects,increased in the soil after functionalized graphene treatment.Redundancy analysis re-vealed that the potential of hydrogen(pH),organic matter,and total phosphorus contributed the most to the changes in bacterial and fungal community composition in the rhizosphere soil.Overall,our findings suggested that the addition of functionalized graphene altered the relative abundances of nitrogen and phosphorus cycling-related microorganisms in peat soil,promoting changes in the physicochemical properties of the soil and ultimately leading to the improved growth of V.faba plants.展开更多
Formaldehyde(HCHO)is formed through the oxidation of volatile organic compounds(VOCs)and can cause human cancer.Bismuth oxide and titanium oxide nanoparticles-functionalized nanographene oxide(Bi_(2)O_(3)/TiO_(2)@NGO)...Formaldehyde(HCHO)is formed through the oxidation of volatile organic compounds(VOCs)and can cause human cancer.Bismuth oxide and titanium oxide nanoparticles-functionalized nanographene oxide(Bi_(2)O_(3)/TiO_(2)@NGO)were used to rapidly remove the HCHO from the air by a photocatalytic degradation-adsorption process(PC-DAP).The formaldehyde vapor in pure air was generated in a dynamic system within a chamber,and flowed over Bi_(2)O_(3)/TiO_(2)@NGO adsorbent inside a fixed-bed quartz reactor(FBQR)under UV irradiation at optimized conditions(250C).At atmospheric pressure,the flow rate and gas hourly space velocity(GHSV)were adjusted to 300 mL/min and 100-450 L/h,respectively.The radicals of HCHO and nanographene oxide(NGO)were generated through the UV-photochemical process,enhancing the chemical adsorption through the radicals’interactions.On the other hand,the semi-degradation process by catalytic oxidation process converted some HCHO into raw materials of CO_(2)and H_(2)O,while the unconverted HCHO was physically absorbed by NGO.Finally,the HCHO concentration in the outlet system was measured by gas chromatography with a flame ionization detector(GC-FID)after derivatizing formaldehyde with 2,4-dinitrophenylhydrazine(DNPH)and acetonitrile.Therefore,efficient removal of HCHO from the air,the removal efficiency of more than 95%,was achieved through physical/chemical adsorption and the semi-degradation.The mean removal efficiencies for HCHO with Bi_(2)O_(3)-TiO_(2)@NGO,TiO_(2)@NGO,Bi_(2)O_(3)@NGO,and NGO were 98.7%,73.6%,61.8%,and 11.4%,respectively(n=10,RSD<5%).The methodology was validated by spiking different concentrations of standard HCHO into pure air.展开更多
Graphene oxide has been used widely as a starting precursor for applications that cater to the needs of tunable graphene. However, the hydrophilic characteristic limits their application, especially in a hydrophobic c...Graphene oxide has been used widely as a starting precursor for applications that cater to the needs of tunable graphene. However, the hydrophilic characteristic limits their application, especially in a hydrophobic condition. Herein, a novel non-covalent surface modification approach towards graphene oxide was conducted via a UV-induced photo-polymerization technique that involves two major routes; a UV-sensitive initiator embedded via pi-pi interactions on the graphene planar rings, and the polymerization of hydrophobic polymeric chains along the surface. The functionalized graphene oxide successfully achieved the desired hydrophobicity as it displayed the characteristic of being readily dissolved in organic solvent. Upon its addition into a polymeric solution and subjected to an electrospinning process,non-woven random nanofibers embedded with graphene oxide sheets were obtained. The prepared polymeric nanofibers were subjected to two-step thermal treatments that eventually converted the polymeric chains into a carbon-rich conductive structure. A unique morphology was observed upon the addition of the functionalized graphene oxide, whereby the sheets were embedded and intercalated within the carbon nanofibers and formed a continuous structure. This reinforcement effectively enhanced the electrochemical performance of the carbon nanofibers by recording a specific capacitance of up to 140.10 F/g at the current density of 1 A/g, which was approximately three folds more than that of pristine nanofibers.It also retained the capacitance up to 96.2% after 1000 vigorous charge/discharge cycles. This functionalization technique opens up a new pathway in tuning the solubility nature of graphene oxide towards the synthesis of a graphene oxide-reinforced polymeric structure.展开更多
A series of β-cyclodextrin （CDs） functionalized graphene nanohybrids have been successfully fabricated utilizing the classical covalent modification methods at different reaction temperatures. It is very interesti...A series of β-cyclodextrin （CDs） functionalized graphene nanohybrids have been successfully fabricated utilizing the classical covalent modification methods at different reaction temperatures. It is very interesting that although both CDs and graphene oxide （GO） could he easily decomposed, the effective combination of GO with CDs leads to significantly enhanced thermal stability of graphene derivatives （GO-CDs）. Moreover, the introduction of CDs could dramatically improve the dispersibility promotion of our products in both polar/protic and nonpolar/aprotic solvents, which will contribute to the preparation of polymer nanocomposites and increase of their thermal stability. The improved thermal degradation temperatures can be obtained for polyvinyl alcohol after filling with as little as 1 wt.% of the hybrid. The obtained products could be potentially used in heat-retardant or thermal-control materials.展开更多
Supercapacitors（SCs） have attracted much attention as one of the alternative energy devices due to their high power performance,long cycle life,and low maintenance cost.Graphene is considered as an innovative and pr...Supercapacitors（SCs） have attracted much attention as one of the alternative energy devices due to their high power performance,long cycle life,and low maintenance cost.Graphene is considered as an innovative and promising material due to its large theoretical specific surface area,high electrical conductivity,good mechanical properties and chemical stability.Herein,we report an effective strategy for elaborately constructing rationally functionalized self-standing graphene（SG） obtained from giant graphene oxide（GGO） paper followed by an ultrarapid thermal-processing.This treatment results in both the exfoliation of graphene sheets and the reduction of GGO by elimination of oxygencontaining groups.The as-prepared SG electrode materials without additive and conducting agent provide an excellent combination of the electrical double layer capacitor（EDLC） and pseudocapacitor（PC） functions and exhibit superior electrochemical performance,including high specific capacitance,good rate capability and excellent cycling stability when investigated in three-electrode electrochemical cells.展开更多
Functionalized graphene nano-platelets(FGN) were obtained via treating graphene nanoplatelets(GN) with HNO3, and served as adsorbent for the removal of Pb2+from solutions. We investigated the FGN adsorption capacity f...Functionalized graphene nano-platelets(FGN) were obtained via treating graphene nanoplatelets(GN) with HNO3, and served as adsorbent for the removal of Pb2+from solutions. We investigated the FGN adsorption capacity for Pb2+at different initial concentrations, varying pH, contact time and temperature. The characterization results of scanning electron microscopy(SEM), thermal analysis(TG/DTG), Fourier transform infrared spectroscopy(FT-IR) and Brunauer-Emmett-Teller(BET) method indicated that FGN layers were thin and possess large specific area with oxygen-containing functional groups grafted onto their surface. Meanwhile, the determined equilibrium adsorption capacity of FGN for Pb2+was 57.765 mg/g and adsorption isotherms well confirmed to Langmuir isotherms models. The results reveals that the FGN has better effect of water treatment.展开更多
In this paper, we investigate the selection rule for desalinating seawater using functionalized graphene sheet as a semi-permissible membrane. Both the applied mathematical modeling and MD simulations will be used to ...In this paper, we investigate the selection rule for desalinating seawater using functionalized graphene sheet as a semi-permissible membrane. Both the applied mathematical modeling and MD simulations will be used to determine the acceptance conditions for water molecule or sodium ion permeating into the functionalized graphene. Both the Lennard-Jones potential and Coulomb forces are considered by taking into accounts the major molecular and ionic interactions between molecules, ions and functionalized graphene sheet. The continuous approximation will then be used to coarse grain most significant molecular and ionic interactions so that the multi-body problems could be simplified into several two-body problems and the 3D motions are reduced into degenerated 1D motion. Our mathematical model and simulations show that the negatively charged graphene always accepts sodium ions and water;however the permeability of water molecules and sodium ions becomes very sensitive to the presence of positive charges on the graphene.展开更多
The nonlinearity of functionalized and nonfunctionlaized graphene as well as gold nanorods were investigated using the Z-scan system with an Ar＋ laser beam tuned at a wavelength of 514 nm in a CW （continuous wave） ...The nonlinearity of functionalized and nonfunctionlaized graphene as well as gold nanorods were investigated using the Z-scan system with an Ar＋ laser beam tuned at a wavelength of 514 nm in a CW （continuous wave） regime that was in resonance with AuNRs （gold nanorods）. Z-scan experimental study indicated that functionalized graphene had a negative nonlinear refraction with self-defocusing performance. The result concluded that gold nanorods （average length was 36 ± 3 nm, and the average diameter was 12 ± 2 nm） enhance the thermal nonlinear properties of graphene oxide materials. Gold nanorods were proved to enhance the nonlinear absorption by 50%, and there was a large enhancement on the thermal nonlinear refraction and the thermo-optical coefficient （dn/dT）. It was observed that the AuFG （functionalized graphene film with gold nanorods） presented a large thermal nonlinear refraction. The value of the nonlinear refraction （nl＇） of FG and AuFG samples was shifted from -0.533 x 10.7 cm2/W to -2.92 x 10-7 cm2/W. There was a large enhancement in thermal refraction value that was about five factors larger than the nonlinear refraction of the host material （FG） and much larger （4 orders of magnitude） than that for AuNRs.展开更多
High mortality of choroidal melanoma(CM)is mainly attributed to the high likelihood of tumorous recurrence.The essential challenge lies in the presence of residual CM cells survived from the antitumor treatment.These ...High mortality of choroidal melanoma(CM)is mainly attributed to the high likelihood of tumorous recurrence.The essential challenge lies in the presence of residual CM cells survived from the antitumor treatment.These residual tumorous cells are most likely to cause tumorous recurrence.This article reports the preparation of a multifunctional nanocomposite which can be used to treat CM efficiently via a chemotherapyassisted-photothermal therapy(CTH-PTT).The nanocomposite comprises of alpha-tocopheryl succinate(α-TOS)and carboxylic chitosan modified graphene(CG).α-TOS has been potentially seen as an efficient CTH antitumor drug while its deficiency such as easy being hydrolyzed by gastrointestinal esterase and poor hydrophilicity inevitable limits the clinic application ofα-TOS.CG is introduced to overcome these shortcomings,offering additional advantages such as the PTT possibility for the antitumor application.The employment of CG-α-TOS on ocular CM cells caused more than 80%inhibition rates after irradiation under an 808 nm laser for 10 min.The outcomes of this work provide a facile and advantageous way to resolve the essential issue of the treatment of ocular tumors such as CM.展开更多
Chemical functionalization of graphene is a topic of paramount importance to broaden its applications in chemistry,physics,and biological science but remains a great challenge due to its low chemical activity and poor...Chemical functionalization of graphene is a topic of paramount importance to broaden its applications in chemistry,physics,and biological science but remains a great challenge due to its low chemical activity and poor dispersion.Here,we report a strategy for the photosynergetic electrochemical functionalization of graphene(EFG).By using chloride ion(Cl^(-))as the intercalation anions and co-reactants,the electrogenerated radicals confined in the expanded graphite layers enable efficient radical addition reaction,thus grasping crystallineperfect EFG.We found that the ultraviolet irradiation and applied voltage have increased the surface/interface concentration of Cl,thus boosting the functionalization of graphene.Theoretical calculation and experimental results verified the oxygen evolution reaction(OER)on EFG has been improved by regulating the doping of chlorine atoms.In addition,the reduced interlayer distance and enhanced electrostatic repulsion near the basal plane endow the fabricated EFG-based membrane with high salt retention.This work highlights a method for the in situ functionalization of graphene and the subsequent applications in OER and water desalination.展开更多
Unique MoS_(2)‐SnS_(2)heterogeneous nanoplates have successfully in‐situ grown on poly(3‐(1‐vinylimidazolium‐3‐yl)propane‐1‐sulfonate)functionalized polypyrrole/graphene oxide(PVIPS/PPy/GO).PVIPS can attract h...Unique MoS_(2)‐SnS_(2)heterogeneous nanoplates have successfully in‐situ grown on poly(3‐(1‐vinylimidazolium‐3‐yl)propane‐1‐sulfonate)functionalized polypyrrole/graphene oxide(PVIPS/PPy/GO).PVIPS can attract heptamolybdate ion(Mo7O246−)and Sn^(4+)as the precursors by the ion‐exchange,resulting in the simultaneous growth of 1T’‐MoS2 and the berndtite‐2T‐type hexagonal SnS_(2)by the interfacial induced effect of PVIPS.The obtained MoS_(2)‐SnS_(2)/PVIPS/PPy/GO can serve as electrocatalysts,exhibiting good NRR performance by the synergistic effect.The semi‐conducting SnS_(2)would limit the surface electron accessibility for suppressing HER process of 1T’‐MoS_(2),while metallic 1T’‐MoS_(2)might efficiently improve the NRR electroactivity of SnS_(2)by the creation of Mo‐Sn‐Sn trimer catalytic sites.Otherwise,the irreversible crystal phase transition has taken place during the NRR process.Partial 1T’‐MoS_(2)and SnS_(2)have electrochemically reacted with N_(2),and irreversibly converted into Mo^(2)N and SnxNz due to the formation of Mo−N and Sn−N bonding,meanwhile,partial SnS_(2) has been irreversibly evolved into SnS due to the reduction by the power source in the electrochemical system.It would put forward a new design idea for optimizing the preparation method and electrocatalytic activity of transition metal dichalcogenides.展开更多
It is well-known that chemical functionalization of graphene has the great significance.We report the development of a new synthesis method of chloro-functionalized reduced graphene oxide（rGOCl）.The rGOCl was prepar...It is well-known that chemical functionalization of graphene has the great significance.We report the development of a new synthesis method of chloro-functionalized reduced graphene oxide（rGOCl）.The rGOCl was prepared by radical reaction,and treatment of carboxyl graphene oxide（GOCOOH） with N-chlorosuccinimide（NCS） at 90℃ for 10 h under an atmosphere of nitrogen,using silver nitrate as catalyst.The morphologies and structures of the prepared materials were investigated by field-emission scanning electron microscopy（FESEM）,X-ray diffraction（XRD）,Fourier transform infrared spectroscopy（FTIR）,Raman spectroscopy and the thermal gravimetric.Results indicated that the rGOCl can be readily obtained from graphene oxide（GO） in three steps.展开更多
Functionalized graphene nano-sheets(FGN) of 0.01%-0.05%(mass fraction) were added to produce FGN-cement composites in the form of mortars. Flow properties, mechanical properties and microstructure of the cementitious ...Functionalized graphene nano-sheets(FGN) of 0.01%-0.05%(mass fraction) were added to produce FGN-cement composites in the form of mortars. Flow properties, mechanical properties and microstructure of the cementitious material were then investigated. The results indicate that the addition of FGN decreases the fluidity slightly and improves mechanical properties of cement-based composites significantly. The highest strength is obtained with FGN content of 0.02% where the flexural strength and compressive strength at 28 days are 12.917 MPa and 52.42 MPa, respectively. Besides, scanning electron micrographs show that FGN can regulate formation of massive compact cross-linking structures and thermo gravimetric analysis indicates that FGN can accelerate the hydration reaction to increase the function of the composite effectively.展开更多
Development of multifunctional and high-performance silicone aerogel is highly required for various promising applications.However,unstable cross-linking structure and poor thermal stability of silicone network as wel...Development of multifunctional and high-performance silicone aerogel is highly required for various promising applications.However,unstable cross-linking structure and poor thermal stability of silicone network as well as complicated processing restrict the practical use significantly.Herein,we report a facile and versatile ambient drying strategy to fabricate lightweight,wide-temperature flexible,super-hydrophobic and flame retardant silicone composite aerogels modified with low-content functionalized graphene oxide(FGO).After optimizing silane molecules,incorporation ofγ-aminopropyltriethoxysilane functionalization is found to promote the dispersion stability of GO during the hydrolysis-polymerization process and thus produce the formation of unique strip-like co-cross-linked network.Consequently,the aerogels containing∼2.0 wt%FGO not only possess good cyclic compressive stability under strain of 70%for 100 cycles and outstanding mechanical reliability in wide temperature range(from liquid nitrogen to 350℃),but also display excellent flame resistance and super-hydrophobicity.Further,the optimized silicone/FGO aerogels display exceptional thermal insulating performance superior to pure aerogel and hydrocarbon polymer foams,and they also show efficient oil absorption and separation capacity for var-ious solvents and oil from water.Clearly,this work provides a new route for the rational design and development of advanced silicone composite aerogels for multifunctional applications.展开更多
Photocatalytic hydrogen(H2)evolution is a promising approach for future sustainable energy utilization.However,it is still a great challenge to develop efficient and stable metal‐free photocatalysts with broadband so...Photocatalytic hydrogen(H2)evolution is a promising approach for future sustainable energy utilization.However,it is still a great challenge to develop efficient and stable metal‐free photocatalysts with broadband solar absorption in the visible region for H2 production.Metal‐free graphene quantum dot(GQD)is an emerging candidate for this purpose because of its good water‐solubility and tunable band gap.On the other hand,metal phosphides(Ni2P,Co2P,etc)have been demonstrated as novel noble‐metal‐free cocatalysts for water splitting,which can efficiently separate electron‐hole pairs and enhance the photocatalytic activities.Herein,we report for the first time on the use of OH‐functionalized GQDs(OH‐GQDs)photosensitizer coupled with Ni2P nanoparticles for photocatalytic H2 production withλ>420 nm light.The H2 production rate is^94 times higher than that of bare OH‐GQDs,which is even comparable to that of OH‐GQDs with 1.0 wt%Pt cocatalyst.This enhancement is probably due to the semiconductor‐cocatalyst interface interaction between Ni2P and OH‐GQDs to facilitate efficient charge transfer process.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
The mixture of graphene oxide （GO） and dye molecules may provide some new applications due to unique electronic, optical, and structural properties. Methylene blue （MB）, a typ- ical anionic dye, can attach on GO v...The mixture of graphene oxide （GO） and dye molecules may provide some new applications due to unique electronic, optical, and structural properties. Methylene blue （MB）, a typ- ical anionic dye, can attach on GO via π-π stacking and electrostatic interaction, and the molecule removal process on GO has been observed. However, it remains unclear about the ultrafast carrier dynamics and the internal energy transfer pathways of the system which is composed of GO and MB. We have employed ultrafast optical pump-probe spectroscopy to investigate the excited dynamics of the GO-MB system dispersed in water by exciting the samples at 400 nm pump pulse. The pristine MB and GO dynamics are also analyzed in tandem for a direct comparison. Utilizing the global analysis to fit the measured signal via a sequential model, five lifetimes are acquired：（0.61±0.01） ps, （3.52±0.04） ps, （14.1±0.3） ps, （84±2） ps, and （3.66±0.08） ns. The ultrafast dynamics corresponding to these lifetimes was analyzed and the new relaxation processes were found in the GO-MB system, compared with the pristine MB. The results reveal that the functionalization of GO can alter the known decay pathways of MB via the energy transfer from GO to MB in system, the increased intermediate state, and the promoted energy transfer from triplet state MB to ground state oxygen molecules dissolved in aqueous sample.展开更多
In this study,the first-order shear deformation theory(FSDT)is used to establish a nonlinear dynamic model for a conical shell truncated by a functionally graded graphene platelet-reinforced composite(FG-GPLRC).The vi...In this study,the first-order shear deformation theory(FSDT)is used to establish a nonlinear dynamic model for a conical shell truncated by a functionally graded graphene platelet-reinforced composite(FG-GPLRC).The vibration analyses of the FG-GPLRC truncated conical shell are presented.Considering the graphene platelets(GPLs)of the FG-GPLRC truncated conical shell with three different distribution patterns,the modified Halpin-Tsai model is used to calculate the effective Young’s modulus.Hamilton’s principle,the FSDT,and the von-Karman type nonlinear geometric relationships are used to derive a system of partial differential governing equations of the FG-GPLRC truncated conical shell.The Galerkin method is used to obtain the ordinary differential equations of the truncated conical shell.Then,the analytical nonlinear frequencies of the FG-GPLRC truncated conical shell are solved by the harmonic balance method.The effects of the weight fraction and distribution pattern of the GPLs,the ratio of the length to the radius as well as the ratio of the radius to the thickness of the FG-GPLRC truncated conical shell on the nonlinear natural frequency characteristics are discussed.This study culminates in the discovery of the periodic motion and chaotic motion of the FG-GPLRC truncated conical shell.展开更多
In this research,to remove sulfur and nitrogen compounds from heavy naphtha,various nanocatalysts were prepared through supporting NiMo over nanoporous graphene and evaluated in hydrodesulfurization and hydrodenitroge...In this research,to remove sulfur and nitrogen compounds from heavy naphtha,various nanocatalysts were prepared through supporting NiMo over nanoporous graphene and evaluated in hydrodesulfurization and hydrodenitrogenation reactions.The nanoporous graphene was initially functionalized in order to facilitate the metal being loaded on it.Three different methods were used to functionalize the nanoporous graphene.The NiMo/nanoporous graphene nanocatalysts were characterized by field emission scanning electron microscopy,Fourier transform infrared spectroscopy,X-ray diffraction,inductively coupled plasma optical emission spectrometry,temperature-programmed reduction,nitrogen adsorption-desorption isotherms and transmission electron microscopy techniques.Catalyst performance was evaluated in terms of conversions of sulfur,mercaptans(R-SH)and nitrogen compounds.It was found that the functionalized nanoporous graphene support could significantly enhance the catalytic performance in comparison with the industrial NiMo/alumina catalyst.Among the functionalized graphene supports,amine-functionalized graphene exhibited the best results.By using NiMo supported over amine-functionalized graphene,the conversions of total sulfur and R-SH reached 97.8%and 98.1%,respectively.展开更多
基金the National Natural Science Foundation of China(Grant number 51771178)Shaanxi Outstanding Youth Fund project(Grant number 2021JC-45)+2 种基金Key international cooperation projects in Shaanxi Province(Grant number 2020KWZ-007)the Major Program of Science and Technology in Shaanxi Province(Grant number20191102006)Open Fund of State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body(Grant number 32115019)。
文摘The poor corrosion and wear resistances of Mg alloys seriously limit their potential applications in various industries.The conventional epoxy coating easily forms many intrinsic defects during the solidification process,which cannot provide sufficient protection.In the current study,we design a double-layer epoxy composite coating on Mg alloy with enhanced anti-corrosion/wear properties,via the spin-assisted assembly technique.The outer layer is functionalized graphene(FG)in waterborne epoxy resin(WEP)and the inner layer is Ce-based conversion(Ce)film.The FG sheets can be homogeneously dispersed within the epoxy matrix to fill the intrinsic defects and improve the barrier capability.The Ce film connects the outer layer with the substrate,showing the transition effect.The corrosion rate of Ce/WEP/FG composite coating is 2131 times lower than that of bare Mg alloy,and the wear rate is decreased by~90%.The improved corrosion resistance is attributed to the labyrinth effect(hindering the penetration of corrosive medium)and the obstruction of galvanic coupling behavior.The synergistic effect derived from the FG sheet and blocking layer exhibits great potential in realizing the improvement of multi-functional integration,which will open up a new avenue for the development of novel composite protection coatings of Mg alloys.
文摘The effect of functionalized graphene on the growth and development of Vicia faba L.was investigated by analyzing its impact on the composition and diversity of the microbial community in rhizosphere peat soil.Seedlings of V.faba planted in this peat soil were treated with either distilled water(CK)or 25 mg·L^(−1)(G25)of functionalized graphene solution.Results showed that the height and root length of V.faba seedlings in the G25 group were significantly larger than those in CK group.The microbial com-munity was analyzed by amplifying and sequencing the 16S rRNA gene V_(3)-V_(4) region of bacteria and internal transcribed spacer re-gion of fungi in rhizosphere soil using Illumina MiSeq technology.Alpha and beta diversity analysis indicated that functionalized graphene increased the richness and diversity of bacteria and fungi in the V.faba rhizosphere peat soil.The abundances of three ni-trogen cycling-related bacteria,Hydrogenophaga,Sphingomonas and Nitrosomonadaceae,were also altered after treatment with the functionalized graphene.The relative abundance of Basilicum,related to soil phosphorus solubilization,decreased in the fungal com-munity,while the relative abundance of Clonostachys and Dimorphospora,which exhibited strong biological control over numerous fungal plant pathogens,nematodes and insects,increased in the soil after functionalized graphene treatment.Redundancy analysis re-vealed that the potential of hydrogen(pH),organic matter,and total phosphorus contributed the most to the changes in bacterial and fungal community composition in the rhizosphere soil.Overall,our findings suggested that the addition of functionalized graphene altered the relative abundances of nitrogen and phosphorus cycling-related microorganisms in peat soil,promoting changes in the physicochemical properties of the soil and ultimately leading to the improved growth of V.faba plants.
基金the Science and Research Branch,Islamic Azad Universitythe Research Institute of Petroleum Industry(RIPI)for supporting this work
文摘Formaldehyde(HCHO)is formed through the oxidation of volatile organic compounds(VOCs)and can cause human cancer.Bismuth oxide and titanium oxide nanoparticles-functionalized nanographene oxide(Bi_(2)O_(3)/TiO_(2)@NGO)were used to rapidly remove the HCHO from the air by a photocatalytic degradation-adsorption process(PC-DAP).The formaldehyde vapor in pure air was generated in a dynamic system within a chamber,and flowed over Bi_(2)O_(3)/TiO_(2)@NGO adsorbent inside a fixed-bed quartz reactor(FBQR)under UV irradiation at optimized conditions(250C).At atmospheric pressure,the flow rate and gas hourly space velocity(GHSV)were adjusted to 300 mL/min and 100-450 L/h,respectively.The radicals of HCHO and nanographene oxide(NGO)were generated through the UV-photochemical process,enhancing the chemical adsorption through the radicals’interactions.On the other hand,the semi-degradation process by catalytic oxidation process converted some HCHO into raw materials of CO_(2)and H_(2)O,while the unconverted HCHO was physically absorbed by NGO.Finally,the HCHO concentration in the outlet system was measured by gas chromatography with a flame ionization detector(GC-FID)after derivatizing formaldehyde with 2,4-dinitrophenylhydrazine(DNPH)and acetonitrile.Therefore,efficient removal of HCHO from the air,the removal efficiency of more than 95%,was achieved through physical/chemical adsorption and the semi-degradation.The mean removal efficiencies for HCHO with Bi_(2)O_(3)-TiO_(2)@NGO,TiO_(2)@NGO,Bi_(2)O_(3)@NGO,and NGO were 98.7%,73.6%,61.8%,and 11.4%,respectively(n=10,RSD<5%).The methodology was validated by spiking different concentrations of standard HCHO into pure air.
文摘Graphene oxide has been used widely as a starting precursor for applications that cater to the needs of tunable graphene. However, the hydrophilic characteristic limits their application, especially in a hydrophobic condition. Herein, a novel non-covalent surface modification approach towards graphene oxide was conducted via a UV-induced photo-polymerization technique that involves two major routes; a UV-sensitive initiator embedded via pi-pi interactions on the graphene planar rings, and the polymerization of hydrophobic polymeric chains along the surface. The functionalized graphene oxide successfully achieved the desired hydrophobicity as it displayed the characteristic of being readily dissolved in organic solvent. Upon its addition into a polymeric solution and subjected to an electrospinning process,non-woven random nanofibers embedded with graphene oxide sheets were obtained. The prepared polymeric nanofibers were subjected to two-step thermal treatments that eventually converted the polymeric chains into a carbon-rich conductive structure. A unique morphology was observed upon the addition of the functionalized graphene oxide, whereby the sheets were embedded and intercalated within the carbon nanofibers and formed a continuous structure. This reinforcement effectively enhanced the electrochemical performance of the carbon nanofibers by recording a specific capacitance of up to 140.10 F/g at the current density of 1 A/g, which was approximately three folds more than that of pristine nanofibers.It also retained the capacitance up to 96.2% after 1000 vigorous charge/discharge cycles. This functionalization technique opens up a new pathway in tuning the solubility nature of graphene oxide towards the synthesis of a graphene oxide-reinforced polymeric structure.
基金supported by China Postdoctoral Science Foundation Funded Project(No.20100481146)Jiangsu Planned Projects for Postdoctoral Research Funds(No.1002015C)+2 种基金Natural Science Foundation of Jiangsu Province(No.BK2011712, BK20130575)National University Student Innovation Program(No.201210288036)NJUST Opening Measuring Fund of Large Precious Apparatus(No.2012-01-15)
文摘A series of β-cyclodextrin （CDs） functionalized graphene nanohybrids have been successfully fabricated utilizing the classical covalent modification methods at different reaction temperatures. It is very interesting that although both CDs and graphene oxide （GO） could he easily decomposed, the effective combination of GO with CDs leads to significantly enhanced thermal stability of graphene derivatives （GO-CDs）. Moreover, the introduction of CDs could dramatically improve the dispersibility promotion of our products in both polar/protic and nonpolar/aprotic solvents, which will contribute to the preparation of polymer nanocomposites and increase of their thermal stability. The improved thermal degradation temperatures can be obtained for polyvinyl alcohol after filling with as little as 1 wt.% of the hybrid. The obtained products could be potentially used in heat-retardant or thermal-control materials.
基金supported by 100 Talents Programme of the Chinese Academy of SciencesNational Program on Key Basic Research Project of China(973 Program,Grant No.2012CB215500)+1 种基金Foundation for Innovative Research Groups of the National Natural Science Foundation of China(Grant No.20921002 and No.21101147)the Science and Technology Development Program of Jilin Province(Grant No.20100102 and 20116008)
文摘Supercapacitors（SCs） have attracted much attention as one of the alternative energy devices due to their high power performance,long cycle life,and low maintenance cost.Graphene is considered as an innovative and promising material due to its large theoretical specific surface area,high electrical conductivity,good mechanical properties and chemical stability.Herein,we report an effective strategy for elaborately constructing rationally functionalized self-standing graphene（SG） obtained from giant graphene oxide（GGO） paper followed by an ultrarapid thermal-processing.This treatment results in both the exfoliation of graphene sheets and the reduction of GGO by elimination of oxygencontaining groups.The as-prepared SG electrode materials without additive and conducting agent provide an excellent combination of the electrical double layer capacitor（EDLC） and pseudocapacitor（PC） functions and exhibit superior electrochemical performance,including high specific capacitance,good rate capability and excellent cycling stability when investigated in three-electrode electrochemical cells.
基金Funded by the National Natural Science Fundation of China(Nos.51678111 and 51478082)
文摘Functionalized graphene nano-platelets(FGN) were obtained via treating graphene nanoplatelets(GN) with HNO3, and served as adsorbent for the removal of Pb2+from solutions. We investigated the FGN adsorption capacity for Pb2+at different initial concentrations, varying pH, contact time and temperature. The characterization results of scanning electron microscopy(SEM), thermal analysis(TG/DTG), Fourier transform infrared spectroscopy(FT-IR) and Brunauer-Emmett-Teller(BET) method indicated that FGN layers were thin and possess large specific area with oxygen-containing functional groups grafted onto their surface. Meanwhile, the determined equilibrium adsorption capacity of FGN for Pb2+was 57.765 mg/g and adsorption isotherms well confirmed to Langmuir isotherms models. The results reveals that the FGN has better effect of water treatment.
文摘In this paper, we investigate the selection rule for desalinating seawater using functionalized graphene sheet as a semi-permissible membrane. Both the applied mathematical modeling and MD simulations will be used to determine the acceptance conditions for water molecule or sodium ion permeating into the functionalized graphene. Both the Lennard-Jones potential and Coulomb forces are considered by taking into accounts the major molecular and ionic interactions between molecules, ions and functionalized graphene sheet. The continuous approximation will then be used to coarse grain most significant molecular and ionic interactions so that the multi-body problems could be simplified into several two-body problems and the 3D motions are reduced into degenerated 1D motion. Our mathematical model and simulations show that the negatively charged graphene always accepts sodium ions and water;however the permeability of water molecules and sodium ions becomes very sensitive to the presence of positive charges on the graphene.
文摘The nonlinearity of functionalized and nonfunctionlaized graphene as well as gold nanorods were investigated using the Z-scan system with an Ar＋ laser beam tuned at a wavelength of 514 nm in a CW （continuous wave） regime that was in resonance with AuNRs （gold nanorods）. Z-scan experimental study indicated that functionalized graphene had a negative nonlinear refraction with self-defocusing performance. The result concluded that gold nanorods （average length was 36 ± 3 nm, and the average diameter was 12 ± 2 nm） enhance the thermal nonlinear properties of graphene oxide materials. Gold nanorods were proved to enhance the nonlinear absorption by 50%, and there was a large enhancement on the thermal nonlinear refraction and the thermo-optical coefficient （dn/dT）. It was observed that the AuFG （functionalized graphene film with gold nanorods） presented a large thermal nonlinear refraction. The value of the nonlinear refraction （nl＇） of FG and AuFG samples was shifted from -0.533 x 10.7 cm2/W to -2.92 x 10-7 cm2/W. There was a large enhancement in thermal refraction value that was about five factors larger than the nonlinear refraction of the host material （FG） and much larger （4 orders of magnitude） than that for AuNRs.
基金financially supported by the National Natural Science Foundation of China(Nos.82202354,U20A20338)the Summit Advancement Disciplines of Zhejiang Province(Wenzhou Medical University Pharmaceutics)Key R&D Program of Zhejiang Province(No.2021C04019)。
文摘High mortality of choroidal melanoma(CM)is mainly attributed to the high likelihood of tumorous recurrence.The essential challenge lies in the presence of residual CM cells survived from the antitumor treatment.These residual tumorous cells are most likely to cause tumorous recurrence.This article reports the preparation of a multifunctional nanocomposite which can be used to treat CM efficiently via a chemotherapyassisted-photothermal therapy(CTH-PTT).The nanocomposite comprises of alpha-tocopheryl succinate(α-TOS)and carboxylic chitosan modified graphene(CG).α-TOS has been potentially seen as an efficient CTH antitumor drug while its deficiency such as easy being hydrolyzed by gastrointestinal esterase and poor hydrophilicity inevitable limits the clinic application ofα-TOS.CG is introduced to overcome these shortcomings,offering additional advantages such as the PTT possibility for the antitumor application.The employment of CG-α-TOS on ocular CM cells caused more than 80%inhibition rates after irradiation under an 808 nm laser for 10 min.The outcomes of this work provide a facile and advantageous way to resolve the essential issue of the treatment of ocular tumors such as CM.
基金supported by the Natural Science Foundation of Guangxi Province(2021GXNSFBA220077,GUIKE AD23026050)National Natural Science Foundation of China(22102035 and 22162006)Innovation Project of Guangxi Graduate Education(XYCBZ2024021).
文摘Chemical functionalization of graphene is a topic of paramount importance to broaden its applications in chemistry,physics,and biological science but remains a great challenge due to its low chemical activity and poor dispersion.Here,we report a strategy for the photosynergetic electrochemical functionalization of graphene(EFG).By using chloride ion(Cl^(-))as the intercalation anions and co-reactants,the electrogenerated radicals confined in the expanded graphite layers enable efficient radical addition reaction,thus grasping crystallineperfect EFG.We found that the ultraviolet irradiation and applied voltage have increased the surface/interface concentration of Cl,thus boosting the functionalization of graphene.Theoretical calculation and experimental results verified the oxygen evolution reaction(OER)on EFG has been improved by regulating the doping of chlorine atoms.In addition,the reduced interlayer distance and enhanced electrostatic repulsion near the basal plane endow the fabricated EFG-based membrane with high salt retention.This work highlights a method for the in situ functionalization of graphene and the subsequent applications in OER and water desalination.
文摘Unique MoS_(2)‐SnS_(2)heterogeneous nanoplates have successfully in‐situ grown on poly(3‐(1‐vinylimidazolium‐3‐yl)propane‐1‐sulfonate)functionalized polypyrrole/graphene oxide(PVIPS/PPy/GO).PVIPS can attract heptamolybdate ion(Mo7O246−)and Sn^(4+)as the precursors by the ion‐exchange,resulting in the simultaneous growth of 1T’‐MoS2 and the berndtite‐2T‐type hexagonal SnS_(2)by the interfacial induced effect of PVIPS.The obtained MoS_(2)‐SnS_(2)/PVIPS/PPy/GO can serve as electrocatalysts,exhibiting good NRR performance by the synergistic effect.The semi‐conducting SnS_(2)would limit the surface electron accessibility for suppressing HER process of 1T’‐MoS_(2),while metallic 1T’‐MoS_(2)might efficiently improve the NRR electroactivity of SnS_(2)by the creation of Mo‐Sn‐Sn trimer catalytic sites.Otherwise,the irreversible crystal phase transition has taken place during the NRR process.Partial 1T’‐MoS_(2)and SnS_(2)have electrochemically reacted with N_(2),and irreversibly converted into Mo^(2)N and SnxNz due to the formation of Mo−N and Sn−N bonding,meanwhile,partial SnS_(2) has been irreversibly evolved into SnS due to the reduction by the power source in the electrochemical system.It would put forward a new design idea for optimizing the preparation method and electrocatalytic activity of transition metal dichalcogenides.
基金financially supported by the Natural Science Foundation of Inner Mongolia (No. 2014BS0202)Inner Mongolia University of Science and Technology Innovation Fund (No. 2014QDL018)Talent Incubation Funding of School of Materials and Metallurgy (No. 2014CY012)
文摘It is well-known that chemical functionalization of graphene has the great significance.We report the development of a new synthesis method of chloro-functionalized reduced graphene oxide（rGOCl）.The rGOCl was prepared by radical reaction,and treatment of carboxyl graphene oxide（GOCOOH） with N-chlorosuccinimide（NCS） at 90℃ for 10 h under an atmosphere of nitrogen,using silver nitrate as catalyst.The morphologies and structures of the prepared materials were investigated by field-emission scanning electron microscopy（FESEM）,X-ray diffraction（XRD）,Fourier transform infrared spectroscopy（FTIR）,Raman spectroscopy and the thermal gravimetric.Results indicated that the rGOCl can be readily obtained from graphene oxide（GO） in three steps.
基金Project(51102035)supported by the National Natural Science Foundation of China
文摘Functionalized graphene nano-sheets(FGN) of 0.01%-0.05%(mass fraction) were added to produce FGN-cement composites in the form of mortars. Flow properties, mechanical properties and microstructure of the cementitious material were then investigated. The results indicate that the addition of FGN decreases the fluidity slightly and improves mechanical properties of cement-based composites significantly. The highest strength is obtained with FGN content of 0.02% where the flexural strength and compressive strength at 28 days are 12.917 MPa and 52.42 MPa, respectively. Besides, scanning electron micrographs show that FGN can regulate formation of massive compact cross-linking structures and thermo gravimetric analysis indicates that FGN can accelerate the hydration reaction to increase the function of the composite effectively.
基金financially supported by the National Natural Science Foundation of China (Nos. 51973047 and 12002112)the Science Foundation and Technology Project of Zhejiang Province (No. Z22E035302)+1 种基金the Science Foundation and Technology Project of Shandong Province (No. ZR2020LFG004)the Project for Science and Technology Program of Hangzhou (Nos. 20191203B16 and 20201203B136)
文摘Development of multifunctional and high-performance silicone aerogel is highly required for various promising applications.However,unstable cross-linking structure and poor thermal stability of silicone network as well as complicated processing restrict the practical use significantly.Herein,we report a facile and versatile ambient drying strategy to fabricate lightweight,wide-temperature flexible,super-hydrophobic and flame retardant silicone composite aerogels modified with low-content functionalized graphene oxide(FGO).After optimizing silane molecules,incorporation ofγ-aminopropyltriethoxysilane functionalization is found to promote the dispersion stability of GO during the hydrolysis-polymerization process and thus produce the formation of unique strip-like co-cross-linked network.Consequently,the aerogels containing∼2.0 wt%FGO not only possess good cyclic compressive stability under strain of 70%for 100 cycles and outstanding mechanical reliability in wide temperature range(from liquid nitrogen to 350℃),but also display excellent flame resistance and super-hydrophobicity.Further,the optimized silicone/FGO aerogels display exceptional thermal insulating performance superior to pure aerogel and hydrocarbon polymer foams,and they also show efficient oil absorption and separation capacity for var-ious solvents and oil from water.Clearly,this work provides a new route for the rational design and development of advanced silicone composite aerogels for multifunctional applications.
文摘Photocatalytic hydrogen(H2)evolution is a promising approach for future sustainable energy utilization.However,it is still a great challenge to develop efficient and stable metal‐free photocatalysts with broadband solar absorption in the visible region for H2 production.Metal‐free graphene quantum dot(GQD)is an emerging candidate for this purpose because of its good water‐solubility and tunable band gap.On the other hand,metal phosphides(Ni2P,Co2P,etc)have been demonstrated as novel noble‐metal‐free cocatalysts for water splitting,which can efficiently separate electron‐hole pairs and enhance the photocatalytic activities.Herein,we report for the first time on the use of OH‐functionalized GQDs(OH‐GQDs)photosensitizer coupled with Ni2P nanoparticles for photocatalytic H2 production withλ>420 nm light.The H2 production rate is^94 times higher than that of bare OH‐GQDs,which is even comparable to that of OH‐GQDs with 1.0 wt%Pt cocatalyst.This enhancement is probably due to the semiconductor‐cocatalyst interface interaction between Ni2P and OH‐GQDs to facilitate efficient charge transfer process.
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This work was supported by the National Natural Basic Research Program of China （No.2013CB922200）,the National Natural Science Foundation of China （No.11674128, No.11474129, and No.11504129）, Jilin Province Scientific and Technological Development Program, China （No.20170101063JC）, the Thirteenth Five- Year Scientific and Technological Research Project of the Education Department of Jilin Province, China （No.n00）.
文摘The mixture of graphene oxide （GO） and dye molecules may provide some new applications due to unique electronic, optical, and structural properties. Methylene blue （MB）, a typ- ical anionic dye, can attach on GO via π-π stacking and electrostatic interaction, and the molecule removal process on GO has been observed. However, it remains unclear about the ultrafast carrier dynamics and the internal energy transfer pathways of the system which is composed of GO and MB. We have employed ultrafast optical pump-probe spectroscopy to investigate the excited dynamics of the GO-MB system dispersed in water by exciting the samples at 400 nm pump pulse. The pristine MB and GO dynamics are also analyzed in tandem for a direct comparison. Utilizing the global analysis to fit the measured signal via a sequential model, five lifetimes are acquired：（0.61±0.01） ps, （3.52±0.04） ps, （14.1±0.3） ps, （84±2） ps, and （3.66±0.08） ns. The ultrafast dynamics corresponding to these lifetimes was analyzed and the new relaxation processes were found in the GO-MB system, compared with the pristine MB. The results reveal that the functionalization of GO can alter the known decay pathways of MB via the energy transfer from GO to MB in system, the increased intermediate state, and the promoted energy transfer from triplet state MB to ground state oxygen molecules dissolved in aqueous sample.
基金Project supported by the National Natural Science Foundation of China(Nos.12002057,11872127,11832002)the Scientific Research Project of Beijing Educational Committee(No.KM202111232023)the Qin Xin Talents Cultivation Program,Beijing Information Science&Technology University(Nos.QXTCP C202102,A201901)。
文摘In this study,the first-order shear deformation theory(FSDT)is used to establish a nonlinear dynamic model for a conical shell truncated by a functionally graded graphene platelet-reinforced composite(FG-GPLRC).The vibration analyses of the FG-GPLRC truncated conical shell are presented.Considering the graphene platelets(GPLs)of the FG-GPLRC truncated conical shell with three different distribution patterns,the modified Halpin-Tsai model is used to calculate the effective Young’s modulus.Hamilton’s principle,the FSDT,and the von-Karman type nonlinear geometric relationships are used to derive a system of partial differential governing equations of the FG-GPLRC truncated conical shell.The Galerkin method is used to obtain the ordinary differential equations of the truncated conical shell.Then,the analytical nonlinear frequencies of the FG-GPLRC truncated conical shell are solved by the harmonic balance method.The effects of the weight fraction and distribution pattern of the GPLs,the ratio of the length to the radius as well as the ratio of the radius to the thickness of the FG-GPLRC truncated conical shell on the nonlinear natural frequency characteristics are discussed.This study culminates in the discovery of the periodic motion and chaotic motion of the FG-GPLRC truncated conical shell.
文摘In this research,to remove sulfur and nitrogen compounds from heavy naphtha,various nanocatalysts were prepared through supporting NiMo over nanoporous graphene and evaluated in hydrodesulfurization and hydrodenitrogenation reactions.The nanoporous graphene was initially functionalized in order to facilitate the metal being loaded on it.Three different methods were used to functionalize the nanoporous graphene.The NiMo/nanoporous graphene nanocatalysts were characterized by field emission scanning electron microscopy,Fourier transform infrared spectroscopy,X-ray diffraction,inductively coupled plasma optical emission spectrometry,temperature-programmed reduction,nitrogen adsorption-desorption isotherms and transmission electron microscopy techniques.Catalyst performance was evaluated in terms of conversions of sulfur,mercaptans(R-SH)and nitrogen compounds.It was found that the functionalized nanoporous graphene support could significantly enhance the catalytic performance in comparison with the industrial NiMo/alumina catalyst.Among the functionalized graphene supports,amine-functionalized graphene exhibited the best results.By using NiMo supported over amine-functionalized graphene,the conversions of total sulfur and R-SH reached 97.8%and 98.1%,respectively.
