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
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
In pursuit of more efficient and stable electrochemical energy storage materials,composite materials consisting of metal oxides and graphene oxide have garnered significant attention due to their unique structures and...In pursuit of more efficient and stable electrochemical energy storage materials,composite materials consisting of metal oxides and graphene oxide have garnered significant attention due to their unique structures and exceptional properties.Graphene oxide(GO),a two-dimensional material with an extremely high specific surface area and excellent conductivity,offers new possibilities for enhancing the electrochemical performance of metal oxides.In this work,we synthesized met-al-organic framework(MOF)and GO composites by regulating the amount of GO,and successfully prepared composites of metal oxides supported by nitrogen-doped carbon frameworks and GO through a simple one-step calcination process.Based on the electrochemical tests,the optimal amount of GO was determined.This research will provide new insights into and directions for designing and synthesizing metal oxide and graphene oxide composite materials with an ideal electro-chemical performance.展开更多
Graphene oxide nanomaterials are increasingly used in various fields due to their superior properties.In order to study the influence of graphene oxide additives on the performance of modified asphalt,in this study,gr...Graphene oxide nanomaterials are increasingly used in various fields due to their superior properties.In order to study the influence of graphene oxide additives on the performance of modified asphalt,in this study,graphene oxide modified asphalt was prepared and characteristics was studied including the high deformation resistance performance and the self-healing property of modified asphalt.Functional groups and morphology of graphene oxide modified asphalt were described by Fourier transform infrared spectroscopy.The high deformation resistance performance and self-healing effect of asphalt samples were obtained through dynamic slear rheometer(DSR)test.Results shows that graphene oxide dispersions improve the performance of asphalt relatively well compared to graphene oxide powder.There is no chemical reaction between graphene oxide and asphalt,but physical connection.The addition of graphene oxide improved the high deformation resistance of modified asphalt and expedited the self-healing ability of asphalt under fatigue load.展开更多
Graphene oxide (GO) reduced by Stachys lavandulifolia extract (SLE) was produced and characterised. The anti-corrosion behaviour of epoxy coatings containing GO and rGO nanosheets was investigated. FESEM-EDS, FT-IR, a...Graphene oxide (GO) reduced by Stachys lavandulifolia extract (SLE) was produced and characterised. The anti-corrosion behaviour of epoxy coatings containing GO and rGO nanosheets was investigated. FESEM-EDS, FT-IR, and Raman spectroscopy were used to examine the microstructure and chemical composition of the nanosheets and epoxy coatings. EIS experiment was used to explore the corrosion behaviour of the coatings. The O/C ratio for GO and rGO-SLE was found to be 2.5 and 4.5, indicating a decrease in the carbon content after the reduction of GO, confirming the adsorption of SLE onto the GO nanosheets. The successful reduction of GO in the presence of SLE particles was confirmed by disappearing the C=O peak and a significant decrease in the C-O-C bond intensity. The epoxy/rGO- SLE coatings exhibited the highest double-layer thickness and excellent corrosion resistance compared to neat epoxy and epoxy/GO coatings, emphasizing the significant role of rGO in enhancing the protective performance of epoxy coatings. The highest values for total charge transfer and film resistances and the inhibition efficiency were observed to be 6529 Ω·cm^(2) and 90%, respectively, for the epoxy/rGO-SLE coated steel plate. It was also found that the epoxy/0.15 wt.% rGO-SLE coating demonstrates the best corrosion resistance performance.展开更多
By enhancing surface interaction between metal oxide particles and carbon-based materials,it can effectively improve Faraday capacitance and conductivity,ultimately achieving high energy density with sufficient redox ...By enhancing surface interaction between metal oxide particles and carbon-based materials,it can effectively improve Faraday capacitance and conductivity,ultimately achieving high energy density with sufficient redox reactions in supercapacitors.Through a gentle biomineralization process and subsequent thermal reduction strategy,we successfully prepared the graphene oxide(GO)wrapping mixed-valence manganese oxides(MnO_(x))and S,P self-codoped carbon matrix porous composite(MnO_(x)@SPC@reduced graphene oxide(RGO)).During the biomineralization process of engineered Pseudomonas sp.(Ml)cells,GO nanosheets functioned as the'soil'to adsorb Mn^(2+)ion and uniformly disperse biogenic Mn oxides(BMO).After undergoing annealing,the MnO_(x) nanoparticles were evenly wrapped with graphene,resulting in the creation of the MnO_(x)@SPC@RGO3 composite.This composite possesses strong C—O—Mn bond interfaces,numerous electroactive sites,and a uniform pore structure.By optimizing the synergistic interaction between the highly conductive graphene and the remarkable surface capacitance of MnO_(x),the MnO_(x)@SPC@RGO3 electrode,with its intercalation Faraday reactions mechanism of■transformations,exhibits an outstanding specific capacity(448.3 F·g^(-1)at 0.5 A·g^(-1)),multiplying performance(340.5 F·g^(-1)at10 A·g^(-1)),and cycling stability(93.8%retention after 5000 cycles).Moreover,the asymmetric all-solidstate supercapacitors of MnO_(x)@SPC@RGO3//PC exhibit an exceptional energy density of 64.8 W·h·kg^(-1)and power density of 350 W·kg^(-1),as well as a long lifespan with capacitance retention of 92.5%after10000 cycles.In conclusion,the synthetic route utilizing biomineralization and thermal reduction exhibits significant potential for exploiting high-performance electrode materials in all-solid-state supercapacitor applications.展开更多
Graphene Oxide(GO),nanoscale Zero-Valent Iron(nZVI)and GO-modified nZVI(GO-nZVI)composite materials were prepared by the Hummer and polyphenol reduction method,respectively,and Scanning Electron Microscope(SEM)and X-r...Graphene Oxide(GO),nanoscale Zero-Valent Iron(nZVI)and GO-modified nZVI(GO-nZVI)composite materials were prepared by the Hummer and polyphenol reduction method,respectively,and Scanning Electron Microscope(SEM)and X-ray Diffraction(XRD)were used to characterize the morphology and phase composition of these materials.A series of batch experiments were then conducted to inves-tigate the performance and influencing factors of GO-nZVI activating peroxydisulfate(SPS)for the degra-dation of 1,2,3-trichloropropane(TCP).Finally,an in-situ oxidation reaction zone was created by GO-nZVI-activated SPS in a one-dimensional simulated system to study the remediation of TCP contamination under different aquifer conditions.The results showed that the GO-nZVI composite exhibited a porous,fluffy structure,with spherical nZVI particles loaded onto the surface and folds of the GO sheets.Compared with unmodified nZVI particles,the GO-nZVI composite significantly enhanced the removal efficiency of TCP by activated SPS,achieving a removal rate of 67.2%within an hour-78.2%higher than that of the unmodi-fied system.The SPS dosage and the C/Fe ratio in GO-nZVI were found to significantly affect the degradation efficiency of TCP.The removal rate of TCP increased with higher SPS concentration,and a 10%carbon addition,yielded the best activation effect.The one-dimensional simulation results indicated that the removal rate of TCP ranged from 30.1%to 73.3%under different conditions.A larger medium particle size and higher concentrations of reactants(SPS and GO-nZVI)improved pollutant degradation efficiency,increasing TCP removal by 62.1%,23.8%,and 3.7%,respectively.In contrast,a higher groundwater flow velocity was not conducive to the removal of pollutants,with the TCP removal rate decreasing by approxi-mately 41.9%.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 extensive use of polymeric materials in single-use packaging has driven the need to develop biodegradable alternatives.This study investigates the incorporation of graphene oxide(GO)and Moringa oleifera seed oil(M...The extensive use of polymeric materials in single-use packaging has driven the need to develop biodegradable alternatives.This study investigates the incorporation of graphene oxide(GO)and Moringa oleifera seed oil(MOSO)into a gelatin matrix to create polymer films and evaluate their potential as active packaging materials.The properties of these films were evaluated using structural,thermal,mechanical,optical,and physicochemical methods to determine their suitability for food packaging applications.The results showed that GO and MOSO were homogeneously dispersed in the gelatin matrix,forming colloidal particles(around 5μm in diameter).The addition of GO increased opacity by approximately 20 times the base value while MOSO affected light transmittance without impacting opacity.Mechanical properties were affected differently,GO acted as a crosslinking agent reducing elongation and increasing tensile strength at break,on the other hand MOSO acted as a plasticizer,making films more plastic increasing elongation a 30%.These effects counteracted each other,and similar behavior was recorded in differential scanning calorimetry.The films exhibited an improved water vapor resistance,which is crucial for food packaging.These findings indicate that the incorporation of GO and MOSO into a gelatin matrix may produce biodegradable polymer films with enhanced properties,suitable for active packaging in the food industry.展开更多
Paraphenylenediamine(PPDA)-grafted maleic anhydride(MAH)-modified graphene oxide(PGO)was synthesized through a dual modification process.Initially,MAH was employed to modify graphene oxide(GO)to enhance its reactive s...Paraphenylenediamine(PPDA)-grafted maleic anhydride(MAH)-modified graphene oxide(PGO)was synthesized through a dual modification process.Initially,MAH was employed to modify graphene oxide(GO)to enhance its reactive sites.Subsequently,PPDA was utilized for further modification of MAH-modified GO(MGO).Through a comprehensive analysis,the successful grafting of MAH and PPDA onto GO was confirmed.It was concurrently established that the optimal ratio of PPDA to MGO is 1:1.This approach yielded PGO characterized by outstanding dispersibility and barrier properties in epoxy resin(EP)coaings for Q235 steel.The corrosion resistance of EP coatings containing varying amounts of PGO was assessed using electrochemical workstation and salt spray testing.After immersing in a 3.5 wt.%NaCl solution for 300 h,the composite coating containing 0.1 wt.%PGO exhibited superior performance in terms of low-frequency impedance modulus,measuring at 1.1×10^(8)Ωcm^(2).The lowest corrosion current density was 2.32×10^(–10)A cm^(−2),and the self-corrosion voltage was−0.301 V.Additionally,polarization testing indicated that this coating also displayed the lowest corrosion rate,specifically 1.383×10^(–7)mm/a.展开更多
Green hydrogen is crucial for advancing renewable energy technologies and protecting the environment.This study introduces a controllable method for bimetallic nickel-cobalt phosphide on reduced graphene oxide on nick...Green hydrogen is crucial for advancing renewable energy technologies and protecting the environment.This study introduces a controllable method for bimetallic nickel-cobalt phosphide on reduced graphene oxide on nickel foam(NiCo_(3)P.C/NF).The material demonstrated low overpotentials of 58 and 180 mV at10 mA cm^(-2)for hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)in 1.0 M KOH.It achieved excellent electrochemical water-splitting performance with operating voltages of 1.54 and 2.6 V at 10 and 500 mA cm^(-2),respectively.The overall water-splitting performance of NiCo_(3).C/NF was extremely stable after 75 h of operation at 53 mA cm^(-2),retaining 98%efficiency,better than the sample Pt-C+RuO_(2),and outperforming previous reports.Density functional theory(DFT)results revealed a synergistic NiCo_(3)P.C interaction that yields nearly zero Gibbs free energy change(-0.100 eV)and upshift d-band center,the real active site at the Ni in HER,and the lowest overpotentials 0.26 V at the P active sites for OER.Furthermore,electronic charge distribution shows the maximum charge distribution between the NiCo_(3)P phase and graphene sheet heterojunction,enhancing the electrocatalyst conductivity.This combined approach offers an innovative strategy to design sustainable electrocatalysts for water s plitting.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
A widely employed energy technology,known as reverse electrodialysis(RED),holds the promise of delivering clean and renewable electricity from water.This technology involves the interaction of two or more bodies of wa...A widely employed energy technology,known as reverse electrodialysis(RED),holds the promise of delivering clean and renewable electricity from water.This technology involves the interaction of two or more bodies of water with varying concentrations of salt ions.The movement of these ions across a membrane generates electricity.However,the efficiency of these systems faces a challenge due to membrane performance degradation over time,often caused by channel blockages.One potential solution to enhance system efficiency is the use of nanofluidic membranes.These specialized membranes offer high ion exchange capacity,abundant ion sources,and customizable channels with varying sizes and properties.Graphene oxide(GO)-based membranes have emerged as particularly promising candidates in this regard,garnering significant attention in recent literature.This work provides a comprehensive overview of the literature surrounding GO membranes and their applications in RED systems.It also highlights recent advancements in the utilization of GO membranes within these systems.Finally,it explores the potential of these membranes to play a pivotal role in electricity generation within RED systems.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
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
The production of hydrogen peroxide(H_(2)O_(2))via artificial photosynthesis using single-atom semiconductor photocatalysts represents a promising green and sustainable technology.However,its efficiency is still limit...The production of hydrogen peroxide(H_(2)O_(2))via artificial photosynthesis using single-atom semiconductor photocatalysts represents a promising green and sustainable technology.However,its efficiency is still limited by sluggish water oxidation kinetics,poor photogenerated charge separation,and insufficient O_(2)adsorption and activation capabilities.Herein,uniformly dispersed single-atom catalysts(SACs)with a Co-N_(4)coordination structure have been synthesized by thermally transforming cobalt phthalocyanine(CoPc)assemblies pre-anchored on phosphate functionalized reduced graphene oxide(Co@rGO-P),and then used to construct heterojunctions with perylenetetracarboxylic acid(PTA)nanosheets for photocatalytic H_(2)O_(2)production by an in-situ growth method.The optimized Co@rGO-P/PTA achieved an H_(2)O_(2)production rate of 1.4 mmol g^(-1)h^(-1)in pure water,with a 12.9-fold enhancement compared to pristine PTA nanosheets exhibiting competitive photoactivity among reported perylene-based materials.Femtosecond transient absorption spectra,in-situ diffuse reflectance infrared Fourier transform spectra and theoretical calculations reveal that the exceptional performance is attributed to the enhanced electron transfer from PTA to rGO via the phosphate bridge and then to the Co-N_(4),and to the promoted O_(2)adsorption and activation at Co-N_(4)active sites.This work provides a feasible and effective strategy for designing highly efficient single-atom semiconductor heterojunction photocatalysts for H_(2)O_(2)production.展开更多
Neodymium chromium oxide(NdCrO_(3))and NdCrO_(3)/graphene oxide(GO)nanocomposite were synthesized via sol-gel and co-precipitation techniques for being used in high-perfo rmance supercapacitors and for the possible ap...Neodymium chromium oxide(NdCrO_(3))and NdCrO_(3)/graphene oxide(GO)nanocomposite were synthesized via sol-gel and co-precipitation techniques for being used in high-perfo rmance supercapacitors and for the possible application in ultraviolet(UV)materials.Herein the systematic synthesis approach was adopted,which enhances the optical and electrical properties of the grown wide band-gap composite nanomaterial.Structural characterization of the grown materials was attempted using X-ray diffraction(XRD)and scanning electron microscopy(SEM).Most importantly the electrochemical analysis of the grown samples was carried out by employing a glassy carbon electrode and 3 mol/L KOH electrolyte,which demonstrates significant improvements in a specific capacitance of approximately360 F/g,an energy density of approximately 18 Wh/kg,and a maximum power density of approximately 257 W/kg,respectively.Moreover,NdCrO_(3)/GO nanocomposite maintains a cyclic stability of 97.6%after4000 cycles.Photoluminescence(PL)spectroscopy confirms the wide bandgap nature of the NdCrO_(3)and NdCrO_(3)/GO nanocomposite,indicating its potential application in UVC devices.These findings emphasize the potential of the NdCrO_(3)/GO nanocomposite in advancing efficient energy storage solutions and the possibility of being used in UVC technology.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
The mechanical performance of flexible catalysts remains a significant challenge for industrial applications.In this study,graphene oxide(GO)functions as both a binder and a redox mediator,serving as a crucial"br...The mechanical performance of flexible catalysts remains a significant challenge for industrial applications.In this study,graphene oxide(GO)functions as both a binder and a redox mediator,serving as a crucial"bridge"between metal species and the organic foam,thereby substantially enhancing NO_(x) conversion efficiency.Catalytic activity tests demonstrate that the GO-modified MnCo-MS@0.05GO catalyst achieves a NO_(x) conversion rate exceeding 95%.The incorporation of GO strengthens the adhesion between the organic foam and metal components,increases the surface roughness of the sponge,and ensures the uniform and stable distribution of metal active sites.Additionally,GO enhances the content of effective catalytic species,improves electron transfer efficiency in the selective catalytic reduction reaction,and reduces diffusion resistance.To elucidate the NO reduction mechanism,in situ diffuse reflectance infrared Fourier transform spectroscopy and transient reaction studies were performed.The results indicate that as the reaction temperature increases,both the Eley-Rideal and Langmuir-Hinshelwood mechanisms contribute to promoting the SCR reaction rate.展开更多
Graphene oxide(GO)is a two-dimensional carbon material with a graphene-like structure and many oxygen-containing functional groups,and in recent years from research into the unique optical properties of GO,GO-based co...Graphene oxide(GO)is a two-dimensional carbon material with a graphene-like structure and many oxygen-containing functional groups,and in recent years from research into the unique optical properties of GO,GO-based composite materials formed by combining with other materials have shown improved overall performance.Reported here is an investigation of how doping with Ni,Fe,and Ag nanoparticles affects the linear and nonlinear optical properties of GO films.The morphology and structure of films of GO,GO with Ni nanoparticles,GO with Fe nanoparticles,and GO with Ag nanoparticles were studied by laser scanning confocal microscopy,SEM,energy dispersive spectroscopy,XRD,and Raman spectroscopy.UV-visible absorption spectra were used to study the optical absorption properties,and the optical band gaps of GO and the composites were calculated from those spectra via Tauc plots.The results show that the band gaps of GO films can be effectively regulated by metal nanoparticles,and so the properties of GO composites can be manipulated.The nonlinear optical properties of GO and GO-metal-nanoparticle composite films were studied by femtosecond laser Z-scanning.The results show that the femtosecond laser power can be tuned to the optical limiting behavior of GO.The strong synergistic coupling effect between metal nanoparticles and GO enhances the nonlinear absorption and nonlinear refraction of composite thin films.The nonlinear absorption coefficient of the composite thin films is improved significantly,and the optical limiting properties are excellent.GO-metal-nanoparticle composite materials have potential applications and advantages in improving optical absorption,band-gap control,and optical limiting.They can promote the expansion of GO composite materials in various practical applications and are candidates for good optical materials,opening the way to GO photonics.展开更多
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supported by the National Natural Science Foundation of China(51971157)Shenzhen Science and Technology Program(JCYJ20210324115412035,JCYJ202103-24123202008,JCYJ20210324122803009 and ZDS-YS20210813095534001)Guangdong Foundation for Basic and Applied Basic Research Program(2021A1515110880).
文摘In pursuit of more efficient and stable electrochemical energy storage materials,composite materials consisting of metal oxides and graphene oxide have garnered significant attention due to their unique structures and exceptional properties.Graphene oxide(GO),a two-dimensional material with an extremely high specific surface area and excellent conductivity,offers new possibilities for enhancing the electrochemical performance of metal oxides.In this work,we synthesized met-al-organic framework(MOF)and GO composites by regulating the amount of GO,and successfully prepared composites of metal oxides supported by nitrogen-doped carbon frameworks and GO through a simple one-step calcination process.Based on the electrochemical tests,the optimal amount of GO was determined.This research will provide new insights into and directions for designing and synthesizing metal oxide and graphene oxide composite materials with an ideal electro-chemical performance.
基金supported by Gansu Provincial Science and Technology Plan(23CXGA0195)Longnan Science and Technology Plan(2024CX03)。
文摘Graphene oxide nanomaterials are increasingly used in various fields due to their superior properties.In order to study the influence of graphene oxide additives on the performance of modified asphalt,in this study,graphene oxide modified asphalt was prepared and characteristics was studied including the high deformation resistance performance and the self-healing property of modified asphalt.Functional groups and morphology of graphene oxide modified asphalt were described by Fourier transform infrared spectroscopy.The high deformation resistance performance and self-healing effect of asphalt samples were obtained through dynamic slear rheometer(DSR)test.Results shows that graphene oxide dispersions improve the performance of asphalt relatively well compared to graphene oxide powder.There is no chemical reaction between graphene oxide and asphalt,but physical connection.The addition of graphene oxide improved the high deformation resistance of modified asphalt and expedited the self-healing ability of asphalt under fatigue load.
文摘Graphene oxide (GO) reduced by Stachys lavandulifolia extract (SLE) was produced and characterised. The anti-corrosion behaviour of epoxy coatings containing GO and rGO nanosheets was investigated. FESEM-EDS, FT-IR, and Raman spectroscopy were used to examine the microstructure and chemical composition of the nanosheets and epoxy coatings. EIS experiment was used to explore the corrosion behaviour of the coatings. The O/C ratio for GO and rGO-SLE was found to be 2.5 and 4.5, indicating a decrease in the carbon content after the reduction of GO, confirming the adsorption of SLE onto the GO nanosheets. The successful reduction of GO in the presence of SLE particles was confirmed by disappearing the C=O peak and a significant decrease in the C-O-C bond intensity. The epoxy/rGO- SLE coatings exhibited the highest double-layer thickness and excellent corrosion resistance compared to neat epoxy and epoxy/GO coatings, emphasizing the significant role of rGO in enhancing the protective performance of epoxy coatings. The highest values for total charge transfer and film resistances and the inhibition efficiency were observed to be 6529 Ω·cm^(2) and 90%, respectively, for the epoxy/rGO-SLE coated steel plate. It was also found that the epoxy/0.15 wt.% rGO-SLE coating demonstrates the best corrosion resistance performance.
基金supported by the National Natural Science Foundation of China(31900005)the Fund of Science and Technology Department of Henan Province(242102231001,242102320362,242102320157)+1 种基金the Fund of Program for Innovative Research Team(in Science and Technology)in University of Henan Province(23IRTSTHN009)Fund of Key Scientific Research Projects of Higher Education Institutions in Henan Province(22A150048)。
文摘By enhancing surface interaction between metal oxide particles and carbon-based materials,it can effectively improve Faraday capacitance and conductivity,ultimately achieving high energy density with sufficient redox reactions in supercapacitors.Through a gentle biomineralization process and subsequent thermal reduction strategy,we successfully prepared the graphene oxide(GO)wrapping mixed-valence manganese oxides(MnO_(x))and S,P self-codoped carbon matrix porous composite(MnO_(x)@SPC@reduced graphene oxide(RGO)).During the biomineralization process of engineered Pseudomonas sp.(Ml)cells,GO nanosheets functioned as the'soil'to adsorb Mn^(2+)ion and uniformly disperse biogenic Mn oxides(BMO).After undergoing annealing,the MnO_(x) nanoparticles were evenly wrapped with graphene,resulting in the creation of the MnO_(x)@SPC@RGO3 composite.This composite possesses strong C—O—Mn bond interfaces,numerous electroactive sites,and a uniform pore structure.By optimizing the synergistic interaction between the highly conductive graphene and the remarkable surface capacitance of MnO_(x),the MnO_(x)@SPC@RGO3 electrode,with its intercalation Faraday reactions mechanism of■transformations,exhibits an outstanding specific capacity(448.3 F·g^(-1)at 0.5 A·g^(-1)),multiplying performance(340.5 F·g^(-1)at10 A·g^(-1)),and cycling stability(93.8%retention after 5000 cycles).Moreover,the asymmetric all-solidstate supercapacitors of MnO_(x)@SPC@RGO3//PC exhibit an exceptional energy density of 64.8 W·h·kg^(-1)and power density of 350 W·kg^(-1),as well as a long lifespan with capacitance retention of 92.5%after10000 cycles.In conclusion,the synthetic route utilizing biomineralization and thermal reduction exhibits significant potential for exploiting high-performance electrode materials in all-solid-state supercapacitor applications.
基金financially supported by the Basal Research Fund of Chinese Academy of Geological Sciences(NO.SK202318)the Natural Science Foundation of Xiamen,China(No.3502Z20227309)the Natural Science Foundation of Fujian Province of China(NO.2023J01227).
文摘Graphene Oxide(GO),nanoscale Zero-Valent Iron(nZVI)and GO-modified nZVI(GO-nZVI)composite materials were prepared by the Hummer and polyphenol reduction method,respectively,and Scanning Electron Microscope(SEM)and X-ray Diffraction(XRD)were used to characterize the morphology and phase composition of these materials.A series of batch experiments were then conducted to inves-tigate the performance and influencing factors of GO-nZVI activating peroxydisulfate(SPS)for the degra-dation of 1,2,3-trichloropropane(TCP).Finally,an in-situ oxidation reaction zone was created by GO-nZVI-activated SPS in a one-dimensional simulated system to study the remediation of TCP contamination under different aquifer conditions.The results showed that the GO-nZVI composite exhibited a porous,fluffy structure,with spherical nZVI particles loaded onto the surface and folds of the GO sheets.Compared with unmodified nZVI particles,the GO-nZVI composite significantly enhanced the removal efficiency of TCP by activated SPS,achieving a removal rate of 67.2%within an hour-78.2%higher than that of the unmodi-fied system.The SPS dosage and the C/Fe ratio in GO-nZVI were found to significantly affect the degradation efficiency of TCP.The removal rate of TCP increased with higher SPS concentration,and a 10%carbon addition,yielded the best activation effect.The one-dimensional simulation results indicated that the removal rate of TCP ranged from 30.1%to 73.3%under different conditions.A larger medium particle size and higher concentrations of reactants(SPS and GO-nZVI)improved pollutant degradation efficiency,increasing TCP removal by 62.1%,23.8%,and 3.7%,respectively.In contrast,a higher groundwater flow velocity was not conducive to the removal of pollutants,with the TCP removal rate decreasing by approxi-mately 41.9%.
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the University of Cartagena for funding through the Strengthening Project Acta 048-2023.
文摘The extensive use of polymeric materials in single-use packaging has driven the need to develop biodegradable alternatives.This study investigates the incorporation of graphene oxide(GO)and Moringa oleifera seed oil(MOSO)into a gelatin matrix to create polymer films and evaluate their potential as active packaging materials.The properties of these films were evaluated using structural,thermal,mechanical,optical,and physicochemical methods to determine their suitability for food packaging applications.The results showed that GO and MOSO were homogeneously dispersed in the gelatin matrix,forming colloidal particles(around 5μm in diameter).The addition of GO increased opacity by approximately 20 times the base value while MOSO affected light transmittance without impacting opacity.Mechanical properties were affected differently,GO acted as a crosslinking agent reducing elongation and increasing tensile strength at break,on the other hand MOSO acted as a plasticizer,making films more plastic increasing elongation a 30%.These effects counteracted each other,and similar behavior was recorded in differential scanning calorimetry.The films exhibited an improved water vapor resistance,which is crucial for food packaging.These findings indicate that the incorporation of GO and MOSO into a gelatin matrix may produce biodegradable polymer films with enhanced properties,suitable for active packaging in the food industry.
基金supports for this work are the Inner Mongolia Major Science and Technology Project(No.2020ZD0024)Natural Science Foundation of Inner Mongolia(No.2024LHMS05046)+5 种基金Local Science and Technology Development Project of the Central Government(Nos.2021ZY0006 and 2022ZY0011)2023 Inner Mongolia Autonomous Region Doctoral Research Innovation Project(No.B20231023Z)Inner Mongolia Autonomous Region key Research and Technological Achievements Transformation Plan Project(No.2023YFHH0063)Autonomous Region higher education Carbon peak carbon neutral research project(No.STZX202206)Basic Scientific Research Expenses Program of Universities directly under Inner Mongolia Autonomous Region(No.JY20220043)Graphite and Graphene New Materials Discipline Team of Inner Mongolia University of Technology(No.PY202066).
文摘Paraphenylenediamine(PPDA)-grafted maleic anhydride(MAH)-modified graphene oxide(PGO)was synthesized through a dual modification process.Initially,MAH was employed to modify graphene oxide(GO)to enhance its reactive sites.Subsequently,PPDA was utilized for further modification of MAH-modified GO(MGO).Through a comprehensive analysis,the successful grafting of MAH and PPDA onto GO was confirmed.It was concurrently established that the optimal ratio of PPDA to MGO is 1:1.This approach yielded PGO characterized by outstanding dispersibility and barrier properties in epoxy resin(EP)coaings for Q235 steel.The corrosion resistance of EP coatings containing varying amounts of PGO was assessed using electrochemical workstation and salt spray testing.After immersing in a 3.5 wt.%NaCl solution for 300 h,the composite coating containing 0.1 wt.%PGO exhibited superior performance in terms of low-frequency impedance modulus,measuring at 1.1×10^(8)Ωcm^(2).The lowest corrosion current density was 2.32×10^(–10)A cm^(−2),and the self-corrosion voltage was−0.301 V.Additionally,polarization testing indicated that this coating also displayed the lowest corrosion rate,specifically 1.383×10^(–7)mm/a.
基金supported by the Regional Leading Research Center Program(2019R1A5A8080326)funding from the Basic Science Research Program(2021R1F1A1048758,2022R1I1A1A01053248)+1 种基金the Regional Innovation Strategy(RIS)(2023RIS-008)through the National Research Foundation of Korea(NRF),funded by the Ministry of Educationsupported by the National Supercomputing Center,which provided supercomputing resources and technical support(TS-2024-RE-0039)。
文摘Green hydrogen is crucial for advancing renewable energy technologies and protecting the environment.This study introduces a controllable method for bimetallic nickel-cobalt phosphide on reduced graphene oxide on nickel foam(NiCo_(3)P.C/NF).The material demonstrated low overpotentials of 58 and 180 mV at10 mA cm^(-2)for hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)in 1.0 M KOH.It achieved excellent electrochemical water-splitting performance with operating voltages of 1.54 and 2.6 V at 10 and 500 mA cm^(-2),respectively.The overall water-splitting performance of NiCo_(3).C/NF was extremely stable after 75 h of operation at 53 mA cm^(-2),retaining 98%efficiency,better than the sample Pt-C+RuO_(2),and outperforming previous reports.Density functional theory(DFT)results revealed a synergistic NiCo_(3)P.C interaction that yields nearly zero Gibbs free energy change(-0.100 eV)and upshift d-band center,the real active site at the Ni in HER,and the lowest overpotentials 0.26 V at the P active sites for OER.Furthermore,electronic charge distribution shows the maximum charge distribution between the NiCo_(3)P phase and graphene sheet heterojunction,enhancing the electrocatalyst conductivity.This combined approach offers an innovative strategy to design sustainable electrocatalysts for water s plitting.
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Key Research and Development Program of Zhejiang Province,Grant/Award Number:2021C04019National Natural Science Foundation of China,Grant/Award Number:U20A20338Natural Science Foundation of Zhejiang Province,Grant/Award Number:LQ21H180012.
文摘A widely employed energy technology,known as reverse electrodialysis(RED),holds the promise of delivering clean and renewable electricity from water.This technology involves the interaction of two or more bodies of water with varying concentrations of salt ions.The movement of these ions across a membrane generates electricity.However,the efficiency of these systems faces a challenge due to membrane performance degradation over time,often caused by channel blockages.One potential solution to enhance system efficiency is the use of nanofluidic membranes.These specialized membranes offer high ion exchange capacity,abundant ion sources,and customizable channels with varying sizes and properties.Graphene oxide(GO)-based membranes have emerged as particularly promising candidates in this regard,garnering significant attention in recent literature.This work provides a comprehensive overview of the literature surrounding GO membranes and their applications in RED systems.It also highlights recent advancements in the utilization of GO membranes within these systems.Finally,it explores the potential of these membranes to play a pivotal role in electricity generation within RED systems.
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 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.
文摘The production of hydrogen peroxide(H_(2)O_(2))via artificial photosynthesis using single-atom semiconductor photocatalysts represents a promising green and sustainable technology.However,its efficiency is still limited by sluggish water oxidation kinetics,poor photogenerated charge separation,and insufficient O_(2)adsorption and activation capabilities.Herein,uniformly dispersed single-atom catalysts(SACs)with a Co-N_(4)coordination structure have been synthesized by thermally transforming cobalt phthalocyanine(CoPc)assemblies pre-anchored on phosphate functionalized reduced graphene oxide(Co@rGO-P),and then used to construct heterojunctions with perylenetetracarboxylic acid(PTA)nanosheets for photocatalytic H_(2)O_(2)production by an in-situ growth method.The optimized Co@rGO-P/PTA achieved an H_(2)O_(2)production rate of 1.4 mmol g^(-1)h^(-1)in pure water,with a 12.9-fold enhancement compared to pristine PTA nanosheets exhibiting competitive photoactivity among reported perylene-based materials.Femtosecond transient absorption spectra,in-situ diffuse reflectance infrared Fourier transform spectra and theoretical calculations reveal that the exceptional performance is attributed to the enhanced electron transfer from PTA to rGO via the phosphate bridge and then to the Co-N_(4),and to the promoted O_(2)adsorption and activation at Co-N_(4)active sites.This work provides a feasible and effective strategy for designing highly efficient single-atom semiconductor heterojunction photocatalysts for H_(2)O_(2)production.
基金support from the Deanship of Scientific Research at King Khalid University,Saudi Arabia(RGP2/505/45)。
文摘Neodymium chromium oxide(NdCrO_(3))and NdCrO_(3)/graphene oxide(GO)nanocomposite were synthesized via sol-gel and co-precipitation techniques for being used in high-perfo rmance supercapacitors and for the possible application in ultraviolet(UV)materials.Herein the systematic synthesis approach was adopted,which enhances the optical and electrical properties of the grown wide band-gap composite nanomaterial.Structural characterization of the grown materials was attempted using X-ray diffraction(XRD)and scanning electron microscopy(SEM).Most importantly the electrochemical analysis of the grown samples was carried out by employing a glassy carbon electrode and 3 mol/L KOH electrolyte,which demonstrates significant improvements in a specific capacitance of approximately360 F/g,an energy density of approximately 18 Wh/kg,and a maximum power density of approximately 257 W/kg,respectively.Moreover,NdCrO_(3)/GO nanocomposite maintains a cyclic stability of 97.6%after4000 cycles.Photoluminescence(PL)spectroscopy confirms the wide bandgap nature of the NdCrO_(3)and NdCrO_(3)/GO nanocomposite,indicating its potential application in UVC devices.These findings emphasize the potential of the NdCrO_(3)/GO nanocomposite in advancing efficient energy storage solutions and the possibility of being used in UVC technology.
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.
文摘The mechanical performance of flexible catalysts remains a significant challenge for industrial applications.In this study,graphene oxide(GO)functions as both a binder and a redox mediator,serving as a crucial"bridge"between metal species and the organic foam,thereby substantially enhancing NO_(x) conversion efficiency.Catalytic activity tests demonstrate that the GO-modified MnCo-MS@0.05GO catalyst achieves a NO_(x) conversion rate exceeding 95%.The incorporation of GO strengthens the adhesion between the organic foam and metal components,increases the surface roughness of the sponge,and ensures the uniform and stable distribution of metal active sites.Additionally,GO enhances the content of effective catalytic species,improves electron transfer efficiency in the selective catalytic reduction reaction,and reduces diffusion resistance.To elucidate the NO reduction mechanism,in situ diffuse reflectance infrared Fourier transform spectroscopy and transient reaction studies were performed.The results indicate that as the reaction temperature increases,both the Eley-Rideal and Langmuir-Hinshelwood mechanisms contribute to promoting the SCR reaction rate.
基金funded by the Henan Key Laboratory of Intelligent Manufacturing Equipment Integration for Superhard Materials(Grant No.JDKJ2022-01)the Key Lab of Modern Optical Technologies of Education Ministry of China,Soochow University。
文摘Graphene oxide(GO)is a two-dimensional carbon material with a graphene-like structure and many oxygen-containing functional groups,and in recent years from research into the unique optical properties of GO,GO-based composite materials formed by combining with other materials have shown improved overall performance.Reported here is an investigation of how doping with Ni,Fe,and Ag nanoparticles affects the linear and nonlinear optical properties of GO films.The morphology and structure of films of GO,GO with Ni nanoparticles,GO with Fe nanoparticles,and GO with Ag nanoparticles were studied by laser scanning confocal microscopy,SEM,energy dispersive spectroscopy,XRD,and Raman spectroscopy.UV-visible absorption spectra were used to study the optical absorption properties,and the optical band gaps of GO and the composites were calculated from those spectra via Tauc plots.The results show that the band gaps of GO films can be effectively regulated by metal nanoparticles,and so the properties of GO composites can be manipulated.The nonlinear optical properties of GO and GO-metal-nanoparticle composite films were studied by femtosecond laser Z-scanning.The results show that the femtosecond laser power can be tuned to the optical limiting behavior of GO.The strong synergistic coupling effect between metal nanoparticles and GO enhances the nonlinear absorption and nonlinear refraction of composite thin films.The nonlinear absorption coefficient of the composite thin films is improved significantly,and the optical limiting properties are excellent.GO-metal-nanoparticle composite materials have potential applications and advantages in improving optical absorption,band-gap control,and optical limiting.They can promote the expansion of GO composite materials in various practical applications and are candidates for good optical materials,opening the way to GO photonics.
