Artificial intelligence(AI)based models have been used to predict the structural,optical,mechanical,and electrochemical properties of zinc oxide/graphene oxide nanocomposites.Machine learning(ML)models such as Artific...Artificial intelligence(AI)based models have been used to predict the structural,optical,mechanical,and electrochemical properties of zinc oxide/graphene oxide nanocomposites.Machine learning(ML)models such as Artificial Neural Networks(ANN),Support Vector Regression(SVR),Multilayer Perceptron(MLP),and hybrid,along with fuzzy logic tools,were applied to predict the different properties like wavelength at maximum intensity(444 nm),crystallite size(17.50 nm),and optical bandgap(2.85 eV).While some other properties,such as energy density,power density,and charge transfer resistance,were also predicted with the help of datasets of 1000(80:20).In general,the energy parameters were predicted more accurately by hybrid models.The hydrothermal method was used to synthesize graphene oxide(GO)and zinc oxide(ZnO)nanocomposites.The increased surface area,conductivity,and stability of graphene oxide in zinc oxide nanoparticles make the composite an ideal option for energy storage.X-ray diffraction(XRD)confirmed the crystallite size of 17.41 nm for the nanocomposite and the presence of GO(12.8○)peaks.The scanning electron microscope(SEM)showed anchored wrinkled GO sheets on zinc oxide with an average particle size of 2.93μm.Energy-dispersive X-ray spectroscopy(EDX)confirmed the elemental composition,and Fouriertransform infrared spectroscopy(FTIR)revealed the impact of GO on functional groups and electrochemical behavior.Photoluminescence(PL)wavelength of(439 nm)and band gap of(2.81 eV)show that the material is suitable for energy applications in nanocomposites.Smart nanocomposite materials with improved performance in energy storage and related applications were fabricated by combining synthesis,characterization,fuzzy logic,and machine learning in this work.展开更多
We employed oxygen plasma treatment to activate the PTFE surface and introduce oxygencontaining polar groups(-OH,C-O,C=O),thereby enhancing surface energy and interfacial reactivity.We subsequently composited the modi...We employed oxygen plasma treatment to activate the PTFE surface and introduce oxygencontaining polar groups(-OH,C-O,C=O),thereby enhancing surface energy and interfacial reactivity.We subsequently composited the modified PTFE(PTFE-O)with graphene oxide(GO),enabling tight interactions between the two phases through hydrogen bonding and van der Waals forces.Comprehensive characterizations,including XPS,FTIR,SEM,and contact angle analysis,confirmed the successful surface modification and uniform dispersion of GO.The optimized PTFE-O/GO composite exhibits a low resistivity of 2.41×10^(3)Ω·cm under a compression pressure of 2 MPa,demonstrating markedly improved conductivity and antistatic performance.These findings provide an effective route for constructing conductive PTFE-based composites and offer new insights into interface-engineered antistatic polymer materials.展开更多
The thermal decomposition characteristic of ammonium perchlorate(AP)represents a critical factor in determining the performance of solid propellants,which has aroused significant interest on the structure and performa...The thermal decomposition characteristic of ammonium perchlorate(AP)represents a critical factor in determining the performance of solid propellants,which has aroused significant interest on the structure and performance improvement of kinds of catalysts.In this study,bimetallic metal-organic frameworks(MOFs),such as CuCo-BTC(BTC=1,3,5-Benzenetricarboxylic acid,H_(3)BTC),CuNi-BTC,and CoNi-BTC,were synthesized by solvothermal(ST)and spray-drying(SD)methods,and then calcined at 400℃for 2 h to form metal oxides.The catalysts as well as their catalytic effects for AP decomposition were characterized by FTIR,XRD,SEM,XPS,TG,DSC,TG-IR,EIS,CV,and LSV.It was found that the rapid coordination of metal ions with ligands during spray drying may lead to catalytic structural defects,promoting the exposure of reactive active sites and increasing the catalytic active region.The results showed that the addition of 2 wt%binary transition metal oxides(BTMOs)as catalysts significantly reduced the high-temperature decomposition(HTD)temperature of AP and enhanced its heat release.Of particular significance is the observation that SD-CoNiO_(x),prepared by spray-drying,reduced the decomposition temperature of AP from 413.26℃(pure AP)to 306℃and enhanced the heat release from 256.79 J/g(pure AP)to 1496.82 J/g,while concomitantly reducing the activation energy by 42%.By analysing the gaseous products during the decomposition of AP+SD-CoNiO_(x)and AP+ST-CoNiO_(x),it was found that SD-CoNiO_(x)could significantly increase the content of high-valent nitrogen oxides during the AP decomposition reaction,which indicates that the BTMOs prepared by spray-drying in the reaction system are more conducive to accelerating the electron transfer in the thermal decomposition process of AP,and can provide a high concentration of reactive oxygen species that oxidize AP to high-valent nitrogen oxide-containing compounds.The present study shows that the structure selectivity of the spray-drying technique influences surfactant molecular arrangement on catalyst surfaces,resulting in their ability to promote higher electron transfer during the catalytic process.Therefore,BTMOs prepared by spray drying method have higher potential for application.展开更多
The commercialization of solid oxide fuel cells depends on the cathode,which possesses both high catalytic activity and a thermal-expansion coefficient(TEC)that aligns with the electrolyte.Although the cobalt-based ca...The commercialization of solid oxide fuel cells depends on the cathode,which possesses both high catalytic activity and a thermal-expansion coefficient(TEC)that aligns with the electrolyte.Although the cobalt-based cathode La_(0.6)Sr_(0.4)CoO_(3)(LSC)offers excellent catalytic performance,its TEC is significantly larger than that of the electrolyte.In this study,we mechanically mix Sm_(0.2)Ce_(0.8)O_(2−δ)(SDC)with LSC to create a composite cathode.By incorporating 50wt%SDC,the TEC decreases significantly from 18.29×10^(−6) to 13.90×10^(−6) K^(−1).Under thermal-shock conditions ranging from room temperature to 800℃,the growth rate of polarization resistance is only 0.658%per cycle,i.e.,merely 49%that of pure LSC.The button cell comprising the LSC-SDC composite cathode operates stably for over 900 h without Sr segregation,with a voltage growth rate of 1.11%/kh.A commercial flat-tube cell(active area:70 cm^(2))compris-ing the LSC-SDC composite cathode delivers 54.8 W at 750℃.The distribution of relaxation-time shows that the non-electrode portion is the main rate-limiting step.This study demonstrates that the LSC-SDC mixture strategy effectively improves the compatibility with the electrolyte while maintaining a high output,thus rendering it a promising commercial cathode material.展开更多
Developing high-capacity carbon-based anode materials is crucial for enhancing the performance of lithium-ion batteries(LIBs).In this study,we presented a nitrogen-doped lignin mesoporous carbon/nickel/nickel oxide(NH...Developing high-capacity carbon-based anode materials is crucial for enhancing the performance of lithium-ion batteries(LIBs).In this study,we presented a nitrogen-doped lignin mesoporous carbon/nickel/nickel oxide(NHMC/Ni/NiO)nanocomposite for developing high-capacity LIBs anode materials through carbonization and selective etching strategies.The synthesized NMHC/Ni/NiO-0.33 composite exhibited a highly regular microstructure with well-dispersed Ni/NiO particles.The composite had a surface area of 408 m^(2)·g^(−1),a mesopore ratio of 75.0%,and a pyridine–nitrogen ratio of 58.9%.The introduction of nitrogen atoms reduced the disordered structure of lignin mesoporous carbon and enhanced its electrical conductivity,thus improving the lithium storage capabilities of the composite.Following 100 cycles at a current density of 0.2 A·g^(−1),the composite demonstrated enhanced Coulomb efficiency and rate performance,achieving a specific discharge capacity of 1230.9 mAh·g^(−1).At a high-current density of 1 A·g^(−1),the composite exhibited an excellent specific discharge capacity of 714.6 mAh·g^(−1).This study presents an innovative method for synthesizing high-performance anode materials of LIBs.展开更多
Against the backdrop of increasingly prominent global energy shortages and environmental issues,the development of efficient energy conversion and storage technologies has become crucial.Zero-dimensional(0D)metal oxid...Against the backdrop of increasingly prominent global energy shortages and environmental issues,the development of efficient energy conversion and storage technologies has become crucial.Zero-dimensional(0D)metal oxide composites exhibit significant application value in the field of energy chemistry due to their unique properties,such as quantum size effect and high specific surface area.From a broad perspective,this paper reviews the main synthesis methods of these composites,including sol-gel method,hydrothermal/solvothermal method,precipitation method,and template method,while analyzing the characteristics of each method.It further discusses their applications in photocatalytic hydrogen production,fuel cells,lithium-ion batteries,and supercapacitors.Additionally,the current challenges,such as material dispersibility and interface bonding,are pointed out,and future development directions are prospected,aiming to provide references for related research.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
Recently,high-entropy materials are attracting enormous attention in battery applications,encompassing both electrode materials and solid electrolytes,due to the pliability and diversification in material composition ...Recently,high-entropy materials are attracting enormous attention in battery applications,encompassing both electrode materials and solid electrolytes,due to the pliability and diversification in material composition and electronic structure.Theoretically,the rapid ion transport and the abundance of surface defects in high-entropy materials suggest a potential for enhancing the performance of composite solid-state electrolytes(CPEs).Herein,using a high-entropy oxide(HEO)filler to assess its potential contributions to CPEs is proposed.The distinctive structural distortions in HEO significantly improve the ionic conductivity(5×10^(−4) S·cm^(−1) at 60℃)and Li-ion transference number(0.57)of CPEs.Furthermore,the enhanced Li-ion transport capability extends the critical current density from 0.6 to 1.5 mA·cm^(−2) in Li/Li symmetric cells.In addition,all-solid-state batteries incorporating the HEO-modified CPEs exhibit superior rate performance and cycling stability.The work will enrich the application of HEOs in CPEs and provide fundamental understanding.展开更多
A chain of GdCe oxides boosted biochars derived from maize straw and sewage sludge(GdyCe1-y/MPBs)were fabricated for formaldehyde(HCHO)catalytic decomposition.The ingenerate relationship between the abatement performa...A chain of GdCe oxides boosted biochars derived from maize straw and sewage sludge(GdyCe1-y/MPBs)were fabricated for formaldehyde(HCHO)catalytic decomposition.The ingenerate relationship between the abatement performance and corresponding structural feature was comprehensively evaluated by XPS,in situ DRIFTS,BET,XRD,SEM and H_(2)-TPR.Meanwhile,10%Gd0.25Ce0.75/MPB exhibited excellent performance,favorable SO_(2) and moisture toleration over a broad temperature range from 160 to 320℃,where it achieved 96.8%removal efficiency with 90.5%selectivity at 200℃.The single or united effects of O_(2),SO_(2),H_(2)O on HCHO abatement over 10%Gd_(0.25)Ce_(0.75)/MPB were tested,and the findings demonstrated that the suppressive effects of SO_(2) and H_(2)O outweighed the promoting influence of O_(2) within a specific range.Gd and Ce co-modified MPB revealed superior HCHO removal capability in contrast to that of Gd or Ce severally modified MPB,ascribing to the synergistic effect of GdO_(x) and CeO_(x) and benefitting from the augmentation of surface area and total pore volume,the aggrandizement of surface active oxygen species,the promotion of redox ability and the inhibition crystallization of CeO_(x).According to in situ DRIFTS,a series of intermediates including formate species and dioxymethylene(DOM)were produced,which would eventually decompose into H_(2)O and CO_(2).In addition,the mass transfer and diffusion of the reactants along with the accessibility of the catalytic sites were enlarged by the hierarchical porous structure of the support,which were also answerable for its distinguished catalytic performance.Furthermore,10%Gd0.25Ce0.75/MPB possessed remarkable potential for industrial applications.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
Mesoporous Ni-Al composite oxide(MNA)with excellent textural and surface properties was prepared using a facile calcination-induced metal heteroatom doping approach and was evaluated as support of Pt-based catalyst fo...Mesoporous Ni-Al composite oxide(MNA)with excellent textural and surface properties was prepared using a facile calcination-induced metal heteroatom doping approach and was evaluated as support of Pt-based catalyst for methylcyclohexane dehydrogenation at a low temperature.The homogeneous incorporation of Ni atoms into the mesoporous framework of alumina and the formation of surface Ni-O-Al bonds benefit the generation of surface coordinated unsaturated aluminum species,which play a crucial role in highly homogenously dispersing Pt active sites in a form of single-atom clusters.Consequently,the resultant catalyst Pt/MNA displayed significantly improved catalytic performance.For example,at 300℃,catalyst Pt/MNA demonstrated a notable catalytic activity with a maximum hydrogen evolution rate of 3057 mmol/gPt/min,even after a long-time reaction up to 100 h or regeneration,which is inspiringly superior to the state-of-the-art supported Ptbased catalysts.The obviously boosted catalytic reactivity of catalyst Pt/MNA can be attributed to the excellent structural and textural properties,the remarkably raised Pt utilization efficiency,and the synergic catalytic effect derived from the interface electron transfer from support MNA to metallic Pt active sites.Our results provided a rational design strategy for the development of promising Pt-based catalyst for methylcyclohexane dehydrogenation,which is vital in the utilization of methylcyclohexane-toluene system for hydrogen storage.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
Carbon fiber-reinforced carbon aerogel(C/CA)composites are one of the most promising candidates for applications requiring both thermal insulation and load bearing capabilities.The preparation of anti-oxidation coatin...Carbon fiber-reinforced carbon aerogel(C/CA)composites are one of the most promising candidates for applications requiring both thermal insulation and load bearing capabilities.The preparation of anti-oxidation coatings on C/CA to address its susceptibility to oxidation is a feasible approach to promote its application in oxidative environments.However,the currently reported coatings on C/CA mainly focus on improving the ablation performance and coating preparation process typically necessitating high-temperature heat treatment.This procedure can increase its thermal conductivity and reduce its thermal insulation ability.In this study,a series of ceramic-resin coatings were fabricated on C/CA through a simple slurry brushing-drying approach at room temperature.The effects of phenolic resin content on the coating structure,residual stress,thermal shock,and oxidation behaviors were investigated.Due to the adhesive properties and curing-induced shrinkage,the PR-7.5 coating(containing 7.5%(in mass)phenolic resin in the slurry)exhibits bonding strength close to fracture strength of the substrate and residual compressive stress of 0.853 GPa,which is beneficial for resisting thermal shock cracking.However,excessive resin content(PR-10.0 containing 10.0%(in mass)phenolic resin in the slurry)induces tensile stress due to uneven curing shrinkage,thereby leading to thermal shock cracking.Meanwhile,oxidation tests reveal significantly reduced weight losses for PR-7.5(17.46%at 800℃/100 min,8.15%at 1000℃/120 min,3.15%at 1200℃/120 min)versus uncoated C/CA’s 44.60%loss at 800℃/20 min.This work provides a brand-new and simple approach to improving the anti-oxidation performance of C/CA and expands its application in mild oxidative environments.展开更多
This study synthesizes and evaluates a novel polysulfone-based membrane doped with graphene oxidepolyethyleneimine-silicon oxide(GO-SiO_(2)-PEI),specifically designed for oily water treatment applications.The function...This study synthesizes and evaluates a novel polysulfone-based membrane doped with graphene oxidepolyethyleneimine-silicon oxide(GO-SiO_(2)-PEI),specifically designed for oily water treatment applications.The functionalization of graphene oxide with SiO_(2) and PEI was rigorously confirmed through comprehensive XRD,FTIR,Raman spectroscopy,and XPS analyses,ensuring the integrity and expected functionality of the nanocomposite.This nanocomposite was integrated into the polysulfone(PSF)membrane matrix,significantly reducing the membrane's inherent hydrophobicity and propensity for fouling.The membranes were meticulously characterized using advanced surface and bulk sensitive apparatus including contact angle and SEM imaging to ascertain their structural and functional attributes.Performance evaluations conducted in a dead-end filtration setup revealed that incorporating 1.0%(mass) of the nanocomposite into the PSF membrane markedly enhanced its porosity and improved the water contact angle.This modification led to an 809% increase in the membrane's water flux and a 57%enhancement in flux recovery rate,while still maintaining a high oil rejection rate and a relatively low leaching rate of 5.3 mg·L^(-1).Analysis through the Owens-Wendt-Kaelble model indicated a significant increase in polar surface energy,corroborating the improved oil rejection capabilities at elevated flux levels.Fouling behavior,analyzed using Hermia's model,identified cake formation as the primary fouling mechanism in most of the tested membranes.Leaching tests further highlighted those membranes with higher nanocomposite loadings exhibited increased leaching rates,suggesting a trade-off between performance enhancement and material stability.展开更多
In recent times,there has been a surge of attention towards advanced high-performance materials for storing energy,specifically in supercapacitors.One encouraging method involves utilizing nanocomposites based on tran...In recent times,there has been a surge of attention towards advanced high-performance materials for storing energy,specifically in supercapacitors.One encouraging method involves utilizing nanocomposites based on transition metal oxides/graphene which have demonstrated significant potential for improving capacitance.The electrochemical properties of titanium oxide doped graphene in current research have been improved through the incorporation of rare earth metals.The hydrothermal technique was chosen for the fabrication of nanocomposites as electrode materials.X-ray diffraction(XRD),Raman spectroscopy,Fourier transform infrared spectroscopy(FT-IR),and scanning electron microscopy(SEM) approaches were employed for the characterization of nanocomposites.Ternary and quaternary nanocomposites with 2 wt% rare earth elements doped with titanium oxide and graphene were synthesized with various ratios of lanthanum and cerium as dopants.In 2 wt% La:Ce-TiO_(2)/rGO,lanthanum,and cerium were doped in 1:1,1:3,and 1:5 ratios.2 wt% La:Ce(1:5)-TiO_(2)/rGO among co-doped composites exhibits better capacitive performance as determined through cyclic voltammetry and galvanostatic charge-discharge.Among all the nanocomposites 422 F/g was the maximum depicted by 2 wt%La:Ce(1:5)-TiO_(2)/rGO at a scan rate of 10 mV/s(potential window from-0.4 to+0.6 V) and 1895 F/g at1 mV/s(potential window-0.6 to+0.6 V).specific capacitance was also determined via GCD,and a maximum capacitance of 486 F/g is depicted by 2 wt% La:Ce(1:5)-TiO_(2)/rGO.The same composites have also served as promising electrode materials in terms of columbic efficiency,power,and energy density.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
High porosity and high brittleness are the main reasons that limit the long-term service life of the alumina-titanium oxide composite coating.Herein,a metastable nanostructured aluminatitanium oxide composite coating ...High porosity and high brittleness are the main reasons that limit the long-term service life of the alumina-titanium oxide composite coating.Herein,a metastable nanostructured aluminatitanium oxide composite coating with high density and high properties was synthesized by plasma spraying of TiO_(2)-Al composite powder.The main phases of the metastable nanostructured alumina-titanium oxide wereγ-Al_(2)O_(3),TiO and AlTiO_(2).The coating,as prepared,contains various metastable microstructures,such as fine-grained,intra-/inter-granular,and"self-locking"microstructures.These metastable microstruc-tures are important for the improvement of hardness and toughness of the coating.Compared with other alumina-based composite coatings,the metastable nanostructured aluminatitanium oxide composite coating showed the most impressive overall performance.The reinforcing and toughening mechanism of the metastable alumina-titanium oxide composite coating included fine grain strengthening and self-toughening of the metastable microstructure.展开更多
SnO_(2)is regarded as a promising lithium storage material due to the advantage of sequential conversion-alloying reaction mechanism.Unfortunately,large volume expansion and undesirable reaction reversibility are iden...SnO_(2)is regarded as a promising lithium storage material due to the advantage of sequential conversion-alloying reaction mechanism.Unfortunately,large volume expansion and undesirable reaction reversibility are identified as two fatal drawbacks.Herein,SnO_(2)nanoparticles encapsulated in graphene oxide-coated porous biochar skeleton(SnO_(2)/PB@GO)are skillfully constructed via an efficient one-step hydrothermal process to be employed as composite anode materials,in which the PB skeleton extracted from waste tea-seed shells possesses enough space to buffer drastic volume variation and the GO coating acts as robust physical matrix to prevent structural degradation.Moreover,double-carbon components successfully anchor SnO_(2)nanoparticles to promote contact and reaction between Sn and Li_(2)O to guarantee high reaction reversibility and structural integration of SnO_(2)/PB@GO electrode.As expected,SnO_(2)/PB@GO-based cell achieves high reversible specific capacity of 783.5 mAh·g^(-1)after 100 cycles at0.1 A.g^(-1)and delivers desirable cycling stability with capacity retention ratio of 81.62%after 300 cycles at1.0 A.g^(-1).Therefore,this work may provide new perspectives on the modification of conversion or alloying typeanodes for lithium-ion batteries and present a feasible strategy to take full advantage of the waste biomass.展开更多
Black nickel coatings have emerged as a research hotspot in materials science due to their excellent performance and broad application prospects.In this study,nickel-based black coatings were fabricated on low-carbon ...Black nickel coatings have emerged as a research hotspot in materials science due to their excellent performance and broad application prospects.In this study,nickel-based black coatings were fabricated on low-carbon steel substrates via photo-assisted electrodeposition.A systematic investigation was conducted on the effects of cerium ion concentration and nano-ceria(CeO_(2))particle content in the electrolyte on the coating properties,along with an analysis of the temporal evolution of coating’s corrosion resistance.When the cerium ion concentration in the electrolyte was 0.05 mol/L,the coating exhibited a uniform black appearance with a light absorption rate of 95%,an emissivity of 0.87,maximum impedance,and the lowest corrosion tendency,demonstrating optimal comprehensive performance.The coating prepared with a nano-ceria concentration of 6 g/L in the electrolyte exhibited an emissivity of 0.9,achieved a 5B adhesion grade(ASTM D3359-09),and demonstrated a one-order-of-magnitude reduction in corrosion current density compared to coatings fabricated without nano-ceria in the electrolyte.With prolonged storage time,the coating's impedance slightly increased,leading to improved corrosion resistance.展开更多
基金extend their gratitude to the Deanship of Scientific Research,Vice Presidency for Graduate Studies and Scientific Research,King Faisal University,Saudi Arabia,for funding the publication of this work under the Ambitious Researcher program(Project No.KFU253806).
文摘Artificial intelligence(AI)based models have been used to predict the structural,optical,mechanical,and electrochemical properties of zinc oxide/graphene oxide nanocomposites.Machine learning(ML)models such as Artificial Neural Networks(ANN),Support Vector Regression(SVR),Multilayer Perceptron(MLP),and hybrid,along with fuzzy logic tools,were applied to predict the different properties like wavelength at maximum intensity(444 nm),crystallite size(17.50 nm),and optical bandgap(2.85 eV).While some other properties,such as energy density,power density,and charge transfer resistance,were also predicted with the help of datasets of 1000(80:20).In general,the energy parameters were predicted more accurately by hybrid models.The hydrothermal method was used to synthesize graphene oxide(GO)and zinc oxide(ZnO)nanocomposites.The increased surface area,conductivity,and stability of graphene oxide in zinc oxide nanoparticles make the composite an ideal option for energy storage.X-ray diffraction(XRD)confirmed the crystallite size of 17.41 nm for the nanocomposite and the presence of GO(12.8○)peaks.The scanning electron microscope(SEM)showed anchored wrinkled GO sheets on zinc oxide with an average particle size of 2.93μm.Energy-dispersive X-ray spectroscopy(EDX)confirmed the elemental composition,and Fouriertransform infrared spectroscopy(FTIR)revealed the impact of GO on functional groups and electrochemical behavior.Photoluminescence(PL)wavelength of(439 nm)and band gap of(2.81 eV)show that the material is suitable for energy applications in nanocomposites.Smart nanocomposite materials with improved performance in energy storage and related applications were fabricated by combining synthesis,characterization,fuzzy logic,and machine learning in this work.
基金Funded by the Key Scientific and Technological Project of Zhejiang Provincial Administration for Market Regulation(No.ZD2024004)the National Natural Science Foundation of China(Nos.62304214 and 62304213)+2 种基金the Natural Science Foundation of Zhejiang Province(No.LQ23E020006)the Chunhui Project Foun-dation of the Education Department of China(No.HZKY20220198)the Fundamental Research Funds for the Provincial Universities of Zhejiang(Nos.2021YW35,2021YW36 and 2022YW62)。
文摘We employed oxygen plasma treatment to activate the PTFE surface and introduce oxygencontaining polar groups(-OH,C-O,C=O),thereby enhancing surface energy and interfacial reactivity.We subsequently composited the modified PTFE(PTFE-O)with graphene oxide(GO),enabling tight interactions between the two phases through hydrogen bonding and van der Waals forces.Comprehensive characterizations,including XPS,FTIR,SEM,and contact angle analysis,confirmed the successful surface modification and uniform dispersion of GO.The optimized PTFE-O/GO composite exhibits a low resistivity of 2.41×10^(3)Ω·cm under a compression pressure of 2 MPa,demonstrating markedly improved conductivity and antistatic performance.These findings provide an effective route for constructing conductive PTFE-based composites and offer new insights into interface-engineered antistatic polymer materials.
基金supported by the National Natural ScienceFoundation of China(Grant No.52203332)。
文摘The thermal decomposition characteristic of ammonium perchlorate(AP)represents a critical factor in determining the performance of solid propellants,which has aroused significant interest on the structure and performance improvement of kinds of catalysts.In this study,bimetallic metal-organic frameworks(MOFs),such as CuCo-BTC(BTC=1,3,5-Benzenetricarboxylic acid,H_(3)BTC),CuNi-BTC,and CoNi-BTC,were synthesized by solvothermal(ST)and spray-drying(SD)methods,and then calcined at 400℃for 2 h to form metal oxides.The catalysts as well as their catalytic effects for AP decomposition were characterized by FTIR,XRD,SEM,XPS,TG,DSC,TG-IR,EIS,CV,and LSV.It was found that the rapid coordination of metal ions with ligands during spray drying may lead to catalytic structural defects,promoting the exposure of reactive active sites and increasing the catalytic active region.The results showed that the addition of 2 wt%binary transition metal oxides(BTMOs)as catalysts significantly reduced the high-temperature decomposition(HTD)temperature of AP and enhanced its heat release.Of particular significance is the observation that SD-CoNiO_(x),prepared by spray-drying,reduced the decomposition temperature of AP from 413.26℃(pure AP)to 306℃and enhanced the heat release from 256.79 J/g(pure AP)to 1496.82 J/g,while concomitantly reducing the activation energy by 42%.By analysing the gaseous products during the decomposition of AP+SD-CoNiO_(x)and AP+ST-CoNiO_(x),it was found that SD-CoNiO_(x)could significantly increase the content of high-valent nitrogen oxides during the AP decomposition reaction,which indicates that the BTMOs prepared by spray-drying in the reaction system are more conducive to accelerating the electron transfer in the thermal decomposition process of AP,and can provide a high concentration of reactive oxygen species that oxidize AP to high-valent nitrogen oxide-containing compounds.The present study shows that the structure selectivity of the spray-drying technique influences surfactant molecular arrangement on catalyst surfaces,resulting in their ability to promote higher electron transfer during the catalytic process.Therefore,BTMOs prepared by spray drying method have higher potential for application.
基金the financial support from the National Natural Science Foundation of China(No.22209191)Ningbo Key R&D Project(No.2023Z155).
文摘The commercialization of solid oxide fuel cells depends on the cathode,which possesses both high catalytic activity and a thermal-expansion coefficient(TEC)that aligns with the electrolyte.Although the cobalt-based cathode La_(0.6)Sr_(0.4)CoO_(3)(LSC)offers excellent catalytic performance,its TEC is significantly larger than that of the electrolyte.In this study,we mechanically mix Sm_(0.2)Ce_(0.8)O_(2−δ)(SDC)with LSC to create a composite cathode.By incorporating 50wt%SDC,the TEC decreases significantly from 18.29×10^(−6) to 13.90×10^(−6) K^(−1).Under thermal-shock conditions ranging from room temperature to 800℃,the growth rate of polarization resistance is only 0.658%per cycle,i.e.,merely 49%that of pure LSC.The button cell comprising the LSC-SDC composite cathode operates stably for over 900 h without Sr segregation,with a voltage growth rate of 1.11%/kh.A commercial flat-tube cell(active area:70 cm^(2))compris-ing the LSC-SDC composite cathode delivers 54.8 W at 750℃.The distribution of relaxation-time shows that the non-electrode portion is the main rate-limiting step.This study demonstrates that the LSC-SDC mixture strategy effectively improves the compatibility with the electrolyte while maintaining a high output,thus rendering it a promising commercial cathode material.
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.22278092,22078116 and 22222805)Guangdong Provincial Key Research and Development Program(No.2020B1111380002)+2 种基金Science and Technology Research Project of Guangzhou(Nos.2023A03J0034,2023A04J0077 and 202102020467)State Key Laboratory of Pulp and Paper Engineering(No.202313)Key Discipline of Materials Science and Engineering,Bureau of Education of Guangzhou(No.202255464).
文摘Developing high-capacity carbon-based anode materials is crucial for enhancing the performance of lithium-ion batteries(LIBs).In this study,we presented a nitrogen-doped lignin mesoporous carbon/nickel/nickel oxide(NHMC/Ni/NiO)nanocomposite for developing high-capacity LIBs anode materials through carbonization and selective etching strategies.The synthesized NMHC/Ni/NiO-0.33 composite exhibited a highly regular microstructure with well-dispersed Ni/NiO particles.The composite had a surface area of 408 m^(2)·g^(−1),a mesopore ratio of 75.0%,and a pyridine–nitrogen ratio of 58.9%.The introduction of nitrogen atoms reduced the disordered structure of lignin mesoporous carbon and enhanced its electrical conductivity,thus improving the lithium storage capabilities of the composite.Following 100 cycles at a current density of 0.2 A·g^(−1),the composite demonstrated enhanced Coulomb efficiency and rate performance,achieving a specific discharge capacity of 1230.9 mAh·g^(−1).At a high-current density of 1 A·g^(−1),the composite exhibited an excellent specific discharge capacity of 714.6 mAh·g^(−1).This study presents an innovative method for synthesizing high-performance anode materials of LIBs.
文摘Against the backdrop of increasingly prominent global energy shortages and environmental issues,the development of efficient energy conversion and storage technologies has become crucial.Zero-dimensional(0D)metal oxide composites exhibit significant application value in the field of energy chemistry due to their unique properties,such as quantum size effect and high specific surface area.From a broad perspective,this paper reviews the main synthesis methods of these composites,including sol-gel method,hydrothermal/solvothermal method,precipitation method,and template method,while analyzing the characteristics of each method.It further discusses their applications in photocatalytic hydrogen production,fuel cells,lithium-ion batteries,and supercapacitors.Additionally,the current challenges,such as material dispersibility and interface bonding,are pointed out,and future development directions are prospected,aiming to provide references for related research.
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supported by the National Natural Science Foundation of China(No.52002094)Shenzhen Science and Technology Program(Nos.JCYJ20210324121411031,JSGG202108021253804014 and RCBS20210706092218040)Shenzhen Steady Support Plan(Nos.GXWD20221030205923001 and GXWD20201230155427003-20200824103000001).
文摘Recently,high-entropy materials are attracting enormous attention in battery applications,encompassing both electrode materials and solid electrolytes,due to the pliability and diversification in material composition and electronic structure.Theoretically,the rapid ion transport and the abundance of surface defects in high-entropy materials suggest a potential for enhancing the performance of composite solid-state electrolytes(CPEs).Herein,using a high-entropy oxide(HEO)filler to assess its potential contributions to CPEs is proposed.The distinctive structural distortions in HEO significantly improve the ionic conductivity(5×10^(−4) S·cm^(−1) at 60℃)and Li-ion transference number(0.57)of CPEs.Furthermore,the enhanced Li-ion transport capability extends the critical current density from 0.6 to 1.5 mA·cm^(−2) in Li/Li symmetric cells.In addition,all-solid-state batteries incorporating the HEO-modified CPEs exhibit superior rate performance and cycling stability.The work will enrich the application of HEOs in CPEs and provide fundamental understanding.
基金supported by the Scientific Research Project of Hunan Provincial EducationDepartment(No.22B0458)the National Natural Science Foundation of China(No.52270102).
文摘A chain of GdCe oxides boosted biochars derived from maize straw and sewage sludge(GdyCe1-y/MPBs)were fabricated for formaldehyde(HCHO)catalytic decomposition.The ingenerate relationship between the abatement performance and corresponding structural feature was comprehensively evaluated by XPS,in situ DRIFTS,BET,XRD,SEM and H_(2)-TPR.Meanwhile,10%Gd0.25Ce0.75/MPB exhibited excellent performance,favorable SO_(2) and moisture toleration over a broad temperature range from 160 to 320℃,where it achieved 96.8%removal efficiency with 90.5%selectivity at 200℃.The single or united effects of O_(2),SO_(2),H_(2)O on HCHO abatement over 10%Gd_(0.25)Ce_(0.75)/MPB were tested,and the findings demonstrated that the suppressive effects of SO_(2) and H_(2)O outweighed the promoting influence of O_(2) within a specific range.Gd and Ce co-modified MPB revealed superior HCHO removal capability in contrast to that of Gd or Ce severally modified MPB,ascribing to the synergistic effect of GdO_(x) and CeO_(x) and benefitting from the augmentation of surface area and total pore volume,the aggrandizement of surface active oxygen species,the promotion of redox ability and the inhibition crystallization of CeO_(x).According to in situ DRIFTS,a series of intermediates including formate species and dioxymethylene(DOM)were produced,which would eventually decompose into H_(2)O and CO_(2).In addition,the mass transfer and diffusion of the reactants along with the accessibility of the catalytic sites were enlarged by the hierarchical porous structure of the support,which were also answerable for its distinguished catalytic performance.Furthermore,10%Gd0.25Ce0.75/MPB possessed remarkable potential for industrial applications.
基金supported by the National Natural Science Foundation of China(no.22109023,no.22179022,and no.22209027)the Youth Innovation Fund of Fujian Province(no.2021J05043 and no.2022J05046)+5 种基金the National Key Research and Development Program of China(2023YFC3906300)the FuXiaQuan National Independent Innovation Demonstration Zone Collaborative Innovation Platform(no.2022-P-027)the·“Hundred Talents·Plan”of Fujian Provincethe“Top Young Talents of Young Eagle”Program of Fujian Provincethe Award Program for Fujian Minjiang Scholar Professorshipthe Talent Fund Program of Fujian Normal University.
文摘Sodium-ion batteries have garnered significant attention as a cost-effective alternative to lithium-ion batteries due to the abundance and affordability of sodium precursors.However,the lack of suitable electrode materials with both high capacity and excellent stability continues to hinder their practical viability.Herein,we couple lattice strain and sulfur deficiency effects in a tin monosulfide/reduced graphene oxide composite to enhance sodium storage performance.Experimental results and theoretical calculations reveal that the synergistic effects of lattice strain and sulfur vacancies in tin monosulfide promote rapid(de)intercalation near the surface/edge of the material,thereby enhancing its pseudocapacitive sodium storage properties.Consequently,the strained and defective tin monosulfide/reduced graphene oxide composite demonstrates a high reversible capacity of 511.82 mAh g^(-1) at 1 A g^(-1) and an outstanding rate capability of 450.60 mAh g^(-1) at 3 A g^(-1).This study offers an effective strategy for improving sodium storage performance through lattice strain and defect engineering.
基金supported by the National Natural Science Foundation of China(21975174 and 22378286)the Natural Science Foundation of Shanxi Province,China(202403021221036)+1 种基金the Funds for Central Government to Guide Local Science and Technology Development(YDZJSX2021A014)the Research Project Supported by Shanxi Scholarship Council of China(2024-036).
文摘Mesoporous Ni-Al composite oxide(MNA)with excellent textural and surface properties was prepared using a facile calcination-induced metal heteroatom doping approach and was evaluated as support of Pt-based catalyst for methylcyclohexane dehydrogenation at a low temperature.The homogeneous incorporation of Ni atoms into the mesoporous framework of alumina and the formation of surface Ni-O-Al bonds benefit the generation of surface coordinated unsaturated aluminum species,which play a crucial role in highly homogenously dispersing Pt active sites in a form of single-atom clusters.Consequently,the resultant catalyst Pt/MNA displayed significantly improved catalytic performance.For example,at 300℃,catalyst Pt/MNA demonstrated a notable catalytic activity with a maximum hydrogen evolution rate of 3057 mmol/gPt/min,even after a long-time reaction up to 100 h or regeneration,which is inspiringly superior to the state-of-the-art supported Ptbased catalysts.The obviously boosted catalytic reactivity of catalyst Pt/MNA can be attributed to the excellent structural and textural properties,the remarkably raised Pt utilization efficiency,and the synergic catalytic effect derived from the interface electron transfer from support MNA to metallic Pt active sites.Our results provided a rational design strategy for the development of promising Pt-based catalyst for methylcyclohexane dehydrogenation,which is vital in the utilization of methylcyclohexane-toluene system for hydrogen storage.
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National Natural Science Foundation of China(52272075,52472053)Research Fund of Youth Innovation Promotion Association of CAS,China(2021190)Defense Industrial Technology Development Program(JCKY2021130B007)。
文摘Carbon fiber-reinforced carbon aerogel(C/CA)composites are one of the most promising candidates for applications requiring both thermal insulation and load bearing capabilities.The preparation of anti-oxidation coatings on C/CA to address its susceptibility to oxidation is a feasible approach to promote its application in oxidative environments.However,the currently reported coatings on C/CA mainly focus on improving the ablation performance and coating preparation process typically necessitating high-temperature heat treatment.This procedure can increase its thermal conductivity and reduce its thermal insulation ability.In this study,a series of ceramic-resin coatings were fabricated on C/CA through a simple slurry brushing-drying approach at room temperature.The effects of phenolic resin content on the coating structure,residual stress,thermal shock,and oxidation behaviors were investigated.Due to the adhesive properties and curing-induced shrinkage,the PR-7.5 coating(containing 7.5%(in mass)phenolic resin in the slurry)exhibits bonding strength close to fracture strength of the substrate and residual compressive stress of 0.853 GPa,which is beneficial for resisting thermal shock cracking.However,excessive resin content(PR-10.0 containing 10.0%(in mass)phenolic resin in the slurry)induces tensile stress due to uneven curing shrinkage,thereby leading to thermal shock cracking.Meanwhile,oxidation tests reveal significantly reduced weight losses for PR-7.5(17.46%at 800℃/100 min,8.15%at 1000℃/120 min,3.15%at 1200℃/120 min)versus uncoated C/CA’s 44.60%loss at 800℃/20 min.This work provides a brand-new and simple approach to improving the anti-oxidation performance of C/CA and expands its application in mild oxidative environments.
基金made possible by Qatar University internal grant(i-GA-379)graduate sponsorship research award (GSRA7-1-0510-20046) from Qatar National Research Fund (QNRF)。
文摘This study synthesizes and evaluates a novel polysulfone-based membrane doped with graphene oxidepolyethyleneimine-silicon oxide(GO-SiO_(2)-PEI),specifically designed for oily water treatment applications.The functionalization of graphene oxide with SiO_(2) and PEI was rigorously confirmed through comprehensive XRD,FTIR,Raman spectroscopy,and XPS analyses,ensuring the integrity and expected functionality of the nanocomposite.This nanocomposite was integrated into the polysulfone(PSF)membrane matrix,significantly reducing the membrane's inherent hydrophobicity and propensity for fouling.The membranes were meticulously characterized using advanced surface and bulk sensitive apparatus including contact angle and SEM imaging to ascertain their structural and functional attributes.Performance evaluations conducted in a dead-end filtration setup revealed that incorporating 1.0%(mass) of the nanocomposite into the PSF membrane markedly enhanced its porosity and improved the water contact angle.This modification led to an 809% increase in the membrane's water flux and a 57%enhancement in flux recovery rate,while still maintaining a high oil rejection rate and a relatively low leaching rate of 5.3 mg·L^(-1).Analysis through the Owens-Wendt-Kaelble model indicated a significant increase in polar surface energy,corroborating the improved oil rejection capabilities at elevated flux levels.Fouling behavior,analyzed using Hermia's model,identified cake formation as the primary fouling mechanism in most of the tested membranes.Leaching tests further highlighted those membranes with higher nanocomposite loadings exhibited increased leaching rates,suggesting a trade-off between performance enhancement and material stability.
文摘In recent times,there has been a surge of attention towards advanced high-performance materials for storing energy,specifically in supercapacitors.One encouraging method involves utilizing nanocomposites based on transition metal oxides/graphene which have demonstrated significant potential for improving capacitance.The electrochemical properties of titanium oxide doped graphene in current research have been improved through the incorporation of rare earth metals.The hydrothermal technique was chosen for the fabrication of nanocomposites as electrode materials.X-ray diffraction(XRD),Raman spectroscopy,Fourier transform infrared spectroscopy(FT-IR),and scanning electron microscopy(SEM) approaches were employed for the characterization of nanocomposites.Ternary and quaternary nanocomposites with 2 wt% rare earth elements doped with titanium oxide and graphene were synthesized with various ratios of lanthanum and cerium as dopants.In 2 wt% La:Ce-TiO_(2)/rGO,lanthanum,and cerium were doped in 1:1,1:3,and 1:5 ratios.2 wt% La:Ce(1:5)-TiO_(2)/rGO among co-doped composites exhibits better capacitive performance as determined through cyclic voltammetry and galvanostatic charge-discharge.Among all the nanocomposites 422 F/g was the maximum depicted by 2 wt%La:Ce(1:5)-TiO_(2)/rGO at a scan rate of 10 mV/s(potential window from-0.4 to+0.6 V) and 1895 F/g at1 mV/s(potential window-0.6 to+0.6 V).specific capacitance was also determined via GCD,and a maximum capacitance of 486 F/g is depicted by 2 wt% La:Ce(1:5)-TiO_(2)/rGO.The same composites have also served as promising electrode materials in terms of columbic efficiency,power,and energy density.
基金supported by the National Key R&D Program of China(No.2021YFB3700103).
文摘The demand for anisotropic aerogels with excellent comprehensive properties in cutting-edge fields such as aerospace is growing.Based on the above background,a novel heterocyclic para-aramid nanofiber/reduced graphene oxide(HPAN/rGO)composite aerogel was prepared by combining electrospinning and unidirectional freeze-drying.The anisotropic HPAN/rGO composite aerogel exhibited a honeycomb morphology in the direction perpendicular to the growth of ice crystals,and a through-well structure of directed microchannels in the direction parallel to the temperature gradient.By varying the mass ratio of HPAN/rGO,a composite aerogel with an ultra-low density of 5.34-7.81 mg·cm^(-3) and an ultra-high porosity of 98%-99%was obtained.Benefiting from the anisotropic structure,the radial and axial thermal conductivities of HPAN/rGO-3 composite aerogel were 29.37 and 44.35 mW·m^(-1)·K^(-1),respectively.A combination of software simulation and experiments was used to analyze the effect of anisotropic structures on the thermal insulation properties of aerogels.Moreover,due to the intrinsic self-extinguishing properties of heterocyclic para-aramid and the protection of the graphene carbon layer,the composite aerogel also exhibits excellent flame retardancy properties,and its total heat release rate(THR)was only 5.8 kJ·g^(-1),which is far superior to many reported aerogels.Therefore,ultralight anisotropic HPAN/rGO composite aerogels with excellent high-temperature thermal insulation and flame retardancy properties have broad application prospects in complex environments such as aerospace.
基金supported by the National Natural Science Foundation of China(Nos.52371063 and 52072110)the Natural Science Foundation of Hebei Province(No.E2018202034)+1 种基金the Central Funds Guiding the Local Science and Technology Development of Hebei Province(No.236Z7610G)the Graduate Innovation Project of Hebei Province(No.CXZZBS2022035).
文摘High porosity and high brittleness are the main reasons that limit the long-term service life of the alumina-titanium oxide composite coating.Herein,a metastable nanostructured aluminatitanium oxide composite coating with high density and high properties was synthesized by plasma spraying of TiO_(2)-Al composite powder.The main phases of the metastable nanostructured alumina-titanium oxide wereγ-Al_(2)O_(3),TiO and AlTiO_(2).The coating,as prepared,contains various metastable microstructures,such as fine-grained,intra-/inter-granular,and"self-locking"microstructures.These metastable microstruc-tures are important for the improvement of hardness and toughness of the coating.Compared with other alumina-based composite coatings,the metastable nanostructured aluminatitanium oxide composite coating showed the most impressive overall performance.The reinforcing and toughening mechanism of the metastable alumina-titanium oxide composite coating included fine grain strengthening and self-toughening of the metastable microstructure.
基金financially supported by the National Natural Science Foundation of China(Nos.52274292 and 51874046)the Outstanding Youth Foundation of Hubei Province(No.2020CFA090)+1 种基金the Project of Scientific Research of Jingzhou(No.2023EC37)the Young Top-notch Talent Cultivation Program of Hubei Province
文摘SnO_(2)is regarded as a promising lithium storage material due to the advantage of sequential conversion-alloying reaction mechanism.Unfortunately,large volume expansion and undesirable reaction reversibility are identified as two fatal drawbacks.Herein,SnO_(2)nanoparticles encapsulated in graphene oxide-coated porous biochar skeleton(SnO_(2)/PB@GO)are skillfully constructed via an efficient one-step hydrothermal process to be employed as composite anode materials,in which the PB skeleton extracted from waste tea-seed shells possesses enough space to buffer drastic volume variation and the GO coating acts as robust physical matrix to prevent structural degradation.Moreover,double-carbon components successfully anchor SnO_(2)nanoparticles to promote contact and reaction between Sn and Li_(2)O to guarantee high reaction reversibility and structural integration of SnO_(2)/PB@GO electrode.As expected,SnO_(2)/PB@GO-based cell achieves high reversible specific capacity of 783.5 mAh·g^(-1)after 100 cycles at0.1 A.g^(-1)and delivers desirable cycling stability with capacity retention ratio of 81.62%after 300 cycles at1.0 A.g^(-1).Therefore,this work may provide new perspectives on the modification of conversion or alloying typeanodes for lithium-ion batteries and present a feasible strategy to take full advantage of the waste biomass.
文摘Black nickel coatings have emerged as a research hotspot in materials science due to their excellent performance and broad application prospects.In this study,nickel-based black coatings were fabricated on low-carbon steel substrates via photo-assisted electrodeposition.A systematic investigation was conducted on the effects of cerium ion concentration and nano-ceria(CeO_(2))particle content in the electrolyte on the coating properties,along with an analysis of the temporal evolution of coating’s corrosion resistance.When the cerium ion concentration in the electrolyte was 0.05 mol/L,the coating exhibited a uniform black appearance with a light absorption rate of 95%,an emissivity of 0.87,maximum impedance,and the lowest corrosion tendency,demonstrating optimal comprehensive performance.The coating prepared with a nano-ceria concentration of 6 g/L in the electrolyte exhibited an emissivity of 0.9,achieved a 5B adhesion grade(ASTM D3359-09),and demonstrated a one-order-of-magnitude reduction in corrosion current density compared to coatings fabricated without nano-ceria in the electrolyte.With prolonged storage time,the coating's impedance slightly increased,leading to improved corrosion resistance.
