Lithium-ion capacitors(LICs)combine the high power dens-ity of electrical double-layer capacitors with the high energy density of lithium-ion batteries.However,they face practical limitations due to the narrow operati...Lithium-ion capacitors(LICs)combine the high power dens-ity of electrical double-layer capacitors with the high energy density of lithium-ion batteries.However,they face practical limitations due to the narrow operating voltage window of their activated carbon(AC)cathodes.We report a scalable thermal treatment strategy to develop high-voltage-tolerant AC cathodes.Through controlled thermal treatment of commer-cial activated carbon(Raw-AC)under a H_(2)/Ar atmosphere at 400-800℃,the targeted reduction of degradation-prone functional groups can be achieved while preserving the critical pore structure and increasing graph-itic microcrystalline ordering.The AC treated at 400℃(HAC-400)had a significant increase in specific capacity(96.0 vs.75.1 mAh/g at 0.05 A/g)and better rate capability(61.1 vs.36.1 mAh/g at 5 A/g)in half-cell LICs,along with an 83.5%capacity retention over 7400 cycles within an extended voltage range of 2.0-4.2 V in full-cell LICs.Scalability was demonstrated by a 120 g batch production,enabling fabrication of pouch-type LICs with commercial hard carbon anodes that delivered a higher energy density of 28.3 Wh/kg at 1 C,and a peak power density of 12.1 kW/kg compared to devices using raw AC.This simple,industry-compatible approach may be used for producing ad-vanced cathode materials for practical high-performance LICs.展开更多
Functional carbon-based materials have become a key research direction in the field of advanced electrocatalysis due to their unique structure and properties.Various strategies have been proposed to design and synthes...Functional carbon-based materials have become a key research direction in the field of advanced electrocatalysis due to their unique structure and properties.Various strategies have been proposed to design and synthesize high-performance carbon-based electrocatalysts.In this review,we comprehensively summarize the latest developments in carbon-based materials for advanced electrocatalysis,with particular emphasis on the structure design strategies and the intrinsic relationship between structure,activity,and performance.The functionalization of multi-dimensional carbon-based materials with enhanced electrocatalytic performance is first addressed.Next,the impact of electronic and structural engineering on the performance of carbon-based materials for electrocatalysis is discussed in terms of the advantages of different types of carbon-based materials in electrocatalytic applications.Finally,the prospects in areas such as precise tuning of functional carbon-based materials,the development of renewable carbon materials,the use of advanced characterization techniques and the promotion of smart manufacturing and responsiveness are high-lighted.展开更多
As a new electrochemical technology,capacitive deionization(CDI)has been increasingly applied in environmental water treatment and seawater desalination.In this study,functional groups modified porous hollow carbon(HC...As a new electrochemical technology,capacitive deionization(CDI)has been increasingly applied in environmental water treatment and seawater desalination.In this study,functional groups modified porous hollow carbon(HC)were synthesized as CDI electrode material for removing Na^(+)and Cl^(−)in salty water.Results showed that the average diameter of HC was approximately 180 nm,and the infrared spectrum showed that its surface was successfully modified with sulfonic and amino groups,respectively.The sulfonic acid functionalized HC(HC-S)showed better electrochemical and desalting performance than the amino-functionalized HC(HC–N),with a maximum Faradic capacity of 287.4 F/g and an adsorptive capacity of 112.97 mg/g for NaCl.Additionally,92.63%capacity retention after 100 adsorption/desorption cycles demonstrates the excellent stability of HC-S.The main findings prove that HC-S is viable as an electrodematerial for desalination by high-performance CDI applications.展开更多
Vanadium redox flow batteries(VRFBs)hold significant promise for large-scale energy storage applications.However,the sluggish reaction kinetics on the electrode surface considerably limit their performance.Implementat...Vanadium redox flow batteries(VRFBs)hold significant promise for large-scale energy storage applications.However,the sluggish reaction kinetics on the electrode surface considerably limit their performance.Implementation of efficient surface modification on carbon electrodes through an economically viable production method is crucial for the practical application of VRFBs.Herein,a nano-carbon layer with morphology of fine nanoparticles(<90 nm)and rich oxygen functional groups was constructed on carbon felts by unbalanced magnetron sputtering coupled with thermal treatment.This modified carbon felt served as both anode and cathode in cell,enabling an improved wettability of electrolyte and high reversibility of the active mass,and promoted kinetics of redox reactions.The optimized carbon felt,achieved through one hour of deposition(1C-CF),demonstrated outstanding electrochemical performance in a single cell.The cell exhibited a high energy efficiency of 82.4%at a current density of 100 m A cm^(-2)and maintained 71.8%at a high current density of 250 mA cm^(-2).Furthermore,the energy efficiency remained at 77.2%during long-term cycling(450 cycles)at a current density of 150 mA cm^(-2),indicating good electrode stability.Our results shed light on the surface design of carbon felt electrodes for the broad application interest of VRFB energy storage systems.展开更多
Stable carbon isotopes(δ^(13)C)are extensively utilized to study intrinsic water use efficiency(iWUE)at the leaf-scale in terrestrial ecosystems,serving as a crucial metric for assessing plant adaptation to climate c...Stable carbon isotopes(δ^(13)C)are extensively utilized to study intrinsic water use efficiency(iWUE)at the leaf-scale in terrestrial ecosystems,serving as a crucial metric for assessing plant adaptation to climate change.However,there is currently a lack of consensus regarding the leaf-scale iWUE variation characteristics among different functional types.In this study,we measured theδ^(13)Cleaf and iWUE values of different functional plants(i.e.,life forms,leaf types,and mycorrhizal types)from 120 species across distinct habitat types(i.e.,hillside,nearpeak,and peak)in a subtropical forest on the western slope of Wuyi Mountains,southern China.The results showed that theδ^(13)Cleaf values of plants on the western slope of Wuyi Mountains ranged from-34.63‰to-30.04‰,and iWUE ranged from 5.93μmol mol^(-1)to 57.34μmol mol^(-1).Theδ^(13)Cleaf and iWUE values differed significantly among plant life forms,following the order of herbs>vine plants>shrubs>trees.Theδ^(13)Cleaf and iWUE values of ectomycorrhizal(ECM)species were greater than those of arbuscular mycorrhizal(AM)species despite there being no significant difference between plants with different leaf types(Simple leaves(SL)vs.Compound leaves(CL)).From the hillside to the peak,both at the community level and at the species level,theδ^(13)C values of leaves and iWUE values of plants exhibited an upward trend.The regression analysis revealed that leaf-scale iWUE was significantly negatively correlated with soil water content and significantly positively correlated with leaf phosphorus content.The findings indicated that leaf carbon isotope fractionation and corresponding iWUE can be influenced by life form,mycorrhizal type,and soil water availability.These insights provide a deeper understanding of the coupling mechanisms of carbon,water,and nutrients among different functional plant types in subtropical forests,and offer insights into predicting plant adaptability under climate change.展开更多
Amino acids are the building blocks of proteins and play vital roles in both biological systems and drug development.In recent years,increasing attention has been given to the functionalization of amino acid derivativ...Amino acids are the building blocks of proteins and play vital roles in both biological systems and drug development.In recent years,increasing attention has been given to the functionalization of amino acid derivatives.Since the introduction of therapeutic insulin in the early 20th century,the conjugation of drug molecules with amino acids and peptides has been pivotal in driving advancements in drug discovery and become an integral part of modern medical practice.Currently,over a hundred peptide-drug conjugates have received global approval and are widely used to treat diseases such as diabetes,cancer,chronic pain,and multiple sclerosis.Key technologies for conjugating peptides with bioactive molecules include antibody-drug conjugates(ADCs),peptide-drug conjugates(PDCs),and proteolysis targeting chimeras(PROTACs).Significant efforts have been dedicated to developing strategies for the modification of amino acids and peptides,with particular focus on site-selective C-H alkylation/arylation reactions.These reactions are crucial for synthesizing bioactive molecules,as they enable the precise introduction of functional groups at specific positions,thereby improving the pharmacological properties of the resulting compounds.展开更多
The over-exploitation of fossil fuel energy has brought about serious environmental problems.It would be of great significance to construct efficient energy conversion and storage system to maximize utilize renewable ...The over-exploitation of fossil fuel energy has brought about serious environmental problems.It would be of great significance to construct efficient energy conversion and storage system to maximize utilize renewable energy,which contributes to reducing environmental hazards.For the past few years,in terms of electrocatalysis and energy storage,carbon fiber materials show great advantages due to its outstanding electrical conductivity,good flexibility and mechanical property.As a simple and low-cost technique,electrospinning can be employed to prepare various nanofibers.It is noted that the functional fiber materials with different special structure and composition can be obtained for energy conversion and storage by combining electrospinning with other post-processing.In this paper,the structural design,controllable synthesis and multifunctional applications of electrospinning-derived functional carbon-based materials(EFCMs)is reviewed.Firstly,we briefly introduce the history,basic principle and typical equipment of electrospinning.Then we discuss the strategies for preparing EFCMs with different structures and composition in detail.In addition,we show recently the application of advanced EFCMs in energy conversion and storage,such as nitrogen species reduction reaction,CO_(2) reduction reaction,oxygen reduction reaction,water-splitting,supercapacitors and ion batteries.In the end,we propose some perspectives on the future development direction of EFCMs.展开更多
Mercury ion(Hg^(2+)),as one of the most toxic heavy metal ions,accumulates easily in the environment,which can generate potential hazards to the ecosystem and human health.To effectively detect and remove Hg^(2+),we f...Mercury ion(Hg^(2+)),as one of the most toxic heavy metal ions,accumulates easily in the environment,which can generate potential hazards to the ecosystem and human health.To effectively detect and remove Hg^(2+),we fabricated four types of carbon dots(CDs)using carboxymethyl nanocellulose as a carbon source doped with different elements using a hydrothermal method.All the CDs exhibited a strong fluorescence emission,excitation-dependent emission and possessed good water dispersibility.Moreover,the four fluorescent CDs were used for Hg^(2+)recognition in aqueous solution,where the CDs-N exhibited better sensitivity and selectivity for Hg^(2+)detection,with a low limit of detection of 8.29×10^(-6)mol/L.It was determined that the fluorescence quenching could be ascribed to a photoinduced charge-transfer processes between Hg^(2+)and the CDs.In addition,the CDs-N were used as a smart invisible ink for anticounterfeiting,information encryption and decryption.Furthermore,the CDs-N were immersed into a cellulose(CMC)-based hydrogel network to prepare fluorescent hydrogels capable of simultaneously detecting and adsorbing Hg^(2+).We anticipate that this research will open possibilities for a green method to synthesize fluorescent CDs for metal ion detection and fluorescent ink production.展开更多
The chemical compound 3-(N-ethylamino)isobutyl)trimethoxysilane(EAMS)modified titanium dioxide(TiO_(2)),producing EAMS-TiO_(2),which was encased in graphitic carbon nitride(GCN)and integrated into epoxy resin(EP).The ...The chemical compound 3-(N-ethylamino)isobutyl)trimethoxysilane(EAMS)modified titanium dioxide(TiO_(2)),producing EAMS-TiO_(2),which was encased in graphitic carbon nitride(GCN)and integrated into epoxy resin(EP).The protective properties of mild steel coated with this nanocomposite in a marine environment were assessedusing electrochemical techniques.Thermogravimetric analysis(TGA)and Cone calorimetry tests demonstrated thatGCN/EAMS-TiO_(2)significantly enhanced the flame retardancy of the epoxy coating,reducing peak heat release rate(PHRR)and total heat release(THR)values by 88%and 70%,respectively,compared to pure EP.Salt spray testsindicated reduced water absorption and improved corrosion resistance.The optimal concentration of 0.6 wt%GCNEAMS/TiO_(2)yielded the highest resistance,with the nanocomposite achieving a coating resistance of 7.50×10^(10)Ω·cm^(2)after 28 d in seawater.The surface resistance of EP-GCN/EAMS-TiO_(2)was over 99.9 times higher than pure EP after onehour in seawater.SECM analysis showed the lowest ferrous ion dissipation(1.0 nA)for EP-GCN/EAMS-TiO_(2)coatedsteel.FE-SEM and EDX analyses revealed improved breakdown products and a durable inert nanolayered covering.Thenanocomposite exhibited excellent water resistance(water contact angle of 167°)and strong mechanical properties,withadhesive strength increasing to 18.3 MPa after 28 d in seawater.EP-GCN/EAMS-TiO_(2)shows potential as a coatingmaterial for the shipping industry.展开更多
Zn metal anodes are usually subject to grave dendrite growth during platting/stripping,which dramatically curtails the lifespan of aqueous Zn-ion batteries and capacitors.To address above problems,in our work,a novel ...Zn metal anodes are usually subject to grave dendrite growth during platting/stripping,which dramatically curtails the lifespan of aqueous Zn-ion batteries and capacitors.To address above problems,in our work,a novel phosphorus-functionalized multichannel carbon interlayer was designed and covered on Zn anodes.The results demonstrated that the multichannel structure combined with the three-dimensional meshy skeleton can provide more sufficient space for Zn deposition,thereby effectively inhibiting the growth of zinc dendrites.Meanwhile,theoretical calculations also confirmed that the P-C and P=O functional groups from phosphorus-functionalized multichannel carbon interlayer have the decisive influence in reducing the zinc nucleation potential and depositing uniformly zinc.Concretely,the symmetrical battery assembled with phosphorus-functionalized multichannel carbon interlayer-covered Zn anodes possessed a long lifetime of 3300 h at 2 mA cm^(-2)with 1 mAh cm^(-2).Furthermore,the full cell with activated carbon cathodes exhibited a high specific capacity of 80.5 mAh g^(-1)and outstanding cycling stability without capacity decay after 15000 cycles at a high current density of 5 A g^(-1).The superior electrochemical performance exceeded that of most reported papers.Consequently,our synthesized zincophilic interlayer with the unique structure has superior prospects for application in stabilizing zinc anodes and prolonging the lifespan of batteries.展开更多
Aqueous zinc ion batteries are regarded as one of the most promising candidates for large-scale energy stor-age due to their high safety,cost-effectiveness,and environ-mental friendliness.However,uncontrolled zinc den...Aqueous zinc ion batteries are regarded as one of the most promising candidates for large-scale energy stor-age due to their high safety,cost-effectiveness,and environ-mental friendliness.However,uncontrolled zinc dendrite growth and side reactions of the zinc anode decrease the sta-bility of Zn batteries.We report the synthesis of an air-oxid-ized carbon nanotube(O-CNT)film by chemical vapor de-position followed by heat treatment in air which is used as a protective layer on the Zn foil to suppress zinc dendrite growth.The increase in the hydrophilicity of the O-CNT film caused by air oxidation facilitates zinc deposition between the film and the anode instead of deposition on the film surface.The porous structure of the O-CNT film homogenizes the Zn^(2+)ion flux and the electric field on the surface of the Zn foil,leading to the uniform deposition of Zn.As a result,a O-CNT@Zn symmetric cell has a much better cycling stability with a life of more than 3000 h at 1 mA cm^(−2) with a capacity of 1 mAh cm^(−2),and values of more than 2000 h and 1 mAh cm^(−2) at 5 mA cm^(−2).In addition,a O-CNT@Zn||Mn^(2+)inserted hydrated vanadium pentoxide(MnVOH)full cell has a better rate per-formance than a Zn||MnVOH cell,achieving a high discharge capacity of 194 mAh g^(−1) at a high current density of 8 A g^(−1).In a long-term cycling test,the O-CNT@Zn||MnVOH full cell has a capacity retention of 58.8%after 2000 cycles at a current density of 5 A·g^(−1).展开更多
Partitioning of soil organic matter for particulate organic carbon(POC)and mineral-associated organic carbon(MAOC)is essential to understand carbon(C)storage under climate change,given their distinct properties and re...Partitioning of soil organic matter for particulate organic carbon(POC)and mineral-associated organic carbon(MAOC)is essential to understand carbon(C)storage under climate change,given their distinct properties and response to warming.The mechanisms underlying warming-induced changes in C pools in black soils(Mollisols)remain unknown,owing to the stability of C pools and the complexity of their associated microbial communities.This study elucidates POC and MAOC contents and their microbial controls in black soils along a mean annual temperature(MAT)gradient from 0.6 to 7.3℃.The POC content(3.3-17 g kg^(−1))increased with MAT,while MAOC content(33-60 g kg^(−1))decreased,indicating accelerated C turnover with warming.Higher MAT shifted the bacterial communities from K-to r-strategies,aligning with increased POC content.The dominance of r-strategists facilitated rapid utilization and mineralization of organic compounds(e.g.,mainly with low C/N ratio),reducing MAOC and increasing POC through sustained plant residue inputs.This shift towards r-strategists also corresponded with increased abundance of saprotrophic fungi and stronger bacteria-saprotrophic fungi associations.Warming in colder regions may release available organic matter that saprotrophic fungi preferentially utilize over plant residues to minimize energy expenditure,decreasing POC decomposition.Our findings suggest that integrating microbial r-/K-strategies help to elucidate these mechanisms and simplify the interpretation of temperature effects on the dynamics of two main functional pools of soil organic matter.展开更多
Trees,mammals,and microbes relate to soil carbon(C)cycle.Trees capture C,and mammals consume plants and other animals,both contributing to organic remains that are then degraded by soil microbes.This organic C can be ...Trees,mammals,and microbes relate to soil carbon(C)cycle.Trees capture C,and mammals consume plants and other animals,both contributing to organic remains that are then degraded by soil microbes.This organic C can be stored in soils or released into the atmosphere through microbial mineralization.Yet,the simultaneous effects of mammals and trees on C consumption by soil microbes have not been investigated.For 30 sampling sites in a mixed forest-savanna environment in southern Guyana,we jointly analyzed observational data of mammal and tree communities along with soil organic matter(SOM)composition(using Fourier transform infrared spectroscopy combined with attenuated total reflectance,energy dispersive X-ray fluorescence spectrometry,and CNH elemental analyzer)and soil microbial C consumption(using Biolog EcoPlates).It was found that higher mammal functional richness(FRic)and functional evenness(FEve)were related to reduced overall C consumption by soil microbes(for FRic:regression coefficient(β)=-0.010,standard error(SE)=0.005,P=0.034;for FEve:β=-0.012,SE=0.005,P=0.010)with the coefficient of determination(R^(2))value of 0.359,explaining 36%of the variance in average well color development values,whereas a higher tree richness was associated with a reduced diversity of C sources consumed by soil microbial communities(β=-0.353,SE=0.172,P=0.041)with the R2 value of 0.290,explaining 29%of the variance in Shannon diversity index values.Our results indicate that mammal and tree communities have complementary effects on soil microbial C consumption,improving our understanding of the functioning of C cycle in the high-diversity Amazon biome.These findings are crucial in elucidating the intricate connections between above-and belowground biodiversity that influence the accumulation and stabilization of soil organic C.展开更多
The efficient electrocatalytic nitrate(NO_(3)^(−))reduction to ammonia(NRA)offers a sustainable alternative for both environmental remediation and ammonia synthesis.Developing advanced electrocatalysts with rationally...The efficient electrocatalytic nitrate(NO_(3)^(−))reduction to ammonia(NRA)offers a sustainable alternative for both environmental remediation and ammonia synthesis.Developing advanced electrocatalysts with rationally designed spatial arrangement of active sites and optimizing the synergetic effect among components are crucial for high efficiency and selectivity.Herein,we present Fe/N active sites decorated on porous carbon nanofibers(CNFs)with encapsulated FeCo nanoparticles(FeCo@CNFs-Fe/N)as electrocatalysts for NRA.The FeCo@CNFs-Fe/N catalyst demonstrates exceptional performance,achieving a high ammonia yield of 498.18μmol/(h·g_(cat)).Meanwhile,the enhanced reduction activity,especially the reduction in overpotential by 0.565 V,is 3–10 times higher than that of FeCo-encapsulated and Fe/N-modified CNFs-based catalysts.The enhanced catalytic activity is attributed to the efficient structure design and optimized spatial distribution of active sites,which enhance the electron transfer rate and decrease the reaction energy barrier.Mechanistic studies reveal that the synergetic effect between encapsulated nanoparticles and surface-modified Fe/N sites plays a crucial role in promoting efficient nitrate adsorption and selective ammonia production.These findings highlight the potential of strategically engineered CNF-based composites for nitrate reduction and other advanced electrocatalytic applications.展开更多
The objective of this study was to identify and synthesize functional groups for the efficient adsorption of volatile organic compounds(VOCs)through a combination of theoretical calculations,molecular design,and exper...The objective of this study was to identify and synthesize functional groups for the efficient adsorption of volatile organic compounds(VOCs)through a combination of theoretical calculations,molecular design,and experimental validation.The density functional theory(DFT)calculation,focusing on the P-containing functional groups,showed that methanol adsorption was dominated by the electrostatic interaction between the carbon surface and methanol,while toluene was mainly trapped through π-π dispersive interaction between toluene molecule and functional group structure.The experimental results showed the phosphorus-doped carbon materials(PCAC)prepared by directly activating potassium phytate had a phosphorus content of up to 4.5%(atom),mainly in the form of C-O-P(O)(OH)_(2).The material exhibited a high specific area(987.6m^(2)·g^(-1))and a large adsorption capacity for methanol(440.0 mg·g^(-1))and toluene(350.1 mg·g^(-1)).These properties were superior to those of the specific commercial activated carbon(CAC)sample used for comparison in this study.The adsorption efficiencies per unit specific surface area of PCAC were 0.45 mg·g^(-1) m^(-2) for methanol and 0.35 mg·g^(-1)·m^(-2) for toluene.This study provided a novel theoretical and experimental framework for the molecular design of polarized elements to enhance the adsorption of polar gases,offering significant advancements over existing commercial solutions.展开更多
The ACF adsorbent with high Cu loading was treated with dielectric barrier discharge plasma to mitigate the negative effects of high Cu loading and enhance PH_(3)and H_(2)S adsorption and oxidation.Bruno-Emmett-Taylor...The ACF adsorbent with high Cu loading was treated with dielectric barrier discharge plasma to mitigate the negative effects of high Cu loading and enhance PH_(3)and H_(2)S adsorption and oxidation.Bruno-Emmett-Taylor(BET)result showed that the specific surface area of the adsorbent after air plasma modification was almost three times that before modification.X-ray photoelectron spectroscopy(XPS)findings revealed that the amino group was added to the adsorbent's surface,increasing lattice oxygen and chemisorbed oxygen.The adsorbent's large specific surface area,excellent surface active oxygen,and abundance of basic groups facilitate PH_(3)and H_(2)S adsorption and oxidation.The scanning electron microscopy showed that air plasma modification exposed more active components and uniformly dispersed them on the surface of adsorbent,thereby improving the adsorption performance.Activity evaluation results showed that the adsorbent has the best ability to capture PH_(3)and H_(2)S after being modified by air plasma at 4 kV voltage for 10 min.The adsorbent's breakthrough ability at high space velocity(WHSV:60,000 h^(−1))is 190 mg P/g and 146 mg S/g,respectively,which is 74%and 60%greater than that before modification.This is a great improvement over previous studies.In addition,the possible mechanism of adsorbent deactivation was proposed.展开更多
Lignin-derived hard carbon shows potential as an anode material for sodium-ion batteries(SIBs)due to its high carbon content and aromatic structure,but its limited reversible adsorption sites and low conductivity hind...Lignin-derived hard carbon shows potential as an anode material for sodium-ion batteries(SIBs)due to its high carbon content and aromatic structure,but its limited reversible adsorption sites and low conductivity hinder performance.This study introduces a self-activation strategy to optimize carbon layer stacking and surface functional groups in microporous carbon,significantly enhancing sodium storage capacity and rate performance.By utilizing oxygen-containing functional groups in organic solvent lignin,we induce micropore formation during pyrolysis,effectively regulating graphite domains and closed pores structures without disrupting carbon layer growth.Unstacked graphene layers serve as efficient electron transport channels and expose additional adsorption sites,simultaneously increasing sodium storage capacity and intrinsic conductivity.The resultant S-OLHC demonstrates a remarkable sodium storage capacity of 358 mA h/g at 0.05 A/g after 200 cycles and maintains 231 mA h/g after 1000 cycles at 2 A/g.This strategy eliminates the need for additional pore-forming agents,offering a simpler,more efficient,and environmentally friendly approach compared to traditional activation methods.This work advances the rational design of high-performance biomass-derived hard carbon for SIBs by leveraging inherent structural characteristics and provides a sustainable low-carbon strategy for lignin valorization in renewable energy storage.展开更多
A tree's basal area(BA)and wood volume scale exponentially with tree diameter in species-specifc patterns.Recent observed increases in tree growth suggest these allometric relationships are shifting in response to...A tree's basal area(BA)and wood volume scale exponentially with tree diameter in species-specifc patterns.Recent observed increases in tree growth suggest these allometric relationships are shifting in response to climate change,rising CO_(2) levels,and/or changes in forest management.We analyzed 9,214 cores from nine conifer and 11 broadleaf species grown in managed mixed-species stands in the upper Midwest to quantify how well diameter(diameter at breast height(DBH))serves to predict BA growth and above-ground wood and carbon(C).These samples include many large trees.We ft mixed models to predict BA growth and above-ground biomass/C from diameter,tree height,and the BA of nearby trees while controlling for site effects.Models account for 55%–83%of the variance in log(recent growth),improving predictions over earlier models.Growth-diameter scaling exponents covary with certain leaf and stem(but not wood)functional traits,reflecting growth strategies.LogBA increment scales linearly with log(diameter)as trees grow bigger in 16/20 species and growth actually accelerates in Quercus rubra L.Three other species plateau in growth.Growth only decelerates in red pine,Pinus resinosa Ait.Growth in whole-tree,above-ground biomass,and C accelerate even more strongly with diameter(mean exponent:2.08 vs.1.30 for BA growth).Sustained BA growth and accelerating wood/C growth contradict the common assumption that tree growth declines in bigger trees.Yield tables and silvicultural guidelines should be updated to reflect these current relationships.Such revisions will favor delaying harvests in many managed stands to increase wood production and enhance ecosystem values including C fxation and storage.Further research may resolve the relative roles of thinning,climatic conditions,nitrogen inputs,and rising CO2 levels on changing patterns of tree growth.展开更多
A mesh-free method is presented to investigate the static bending properties of functionally graded carbon nanotube-reinforced composite(FG-CNTRC)plates.The curvature of the plate is directly interpolated with the nod...A mesh-free method is presented to investigate the static bending properties of functionally graded carbon nanotube-reinforced composite(FG-CNTRC)plates.The curvature of the plate is directly interpolated with the nodal deflections due to the higher-order continuity property of the moving leastsquares approximation,establishing a mesh-free computational scheme where the nodal deflections are the only unknowns.The convergence and efficiency of the proposed method are studied based on a homogeneous square plate.The FG-CNTRC plates are modeled with continuously varying Young’s moduli along the thickness direction according to the volume fraction of the carbon nanotubes(CNTs).Detailed studies have been conducted on the effects of different boundary conditions,CNT volume fractions,geometric shapes,and width-to-thickness ratios on bending behavior.CNT efficiency parameters are introduced to account for load transfer between the nanotubes and the matrix,treating the nanocomposites as orthotropic materials.However,in the actual structure,arranging the CNTs in the desired direction is more difficult compared to other fibers.Therefore,in the present study,CNTs in the composites are considered to be arranged randomly,resulting in the composite properties being treated as isotropic.The study includes second-order derivatives of deflections,and the finite element method typically requires C1 continuity for interpolation,which introduces challenges in building elements and constructing interpolation functions.The distinct advantage of the mesh-free method is that it requires only C0 weight functions.A mesh-free computational scheme based on moving leastsquares approximations for composite plates using Kirchhoffplate theory is established.Bending analyses of homogeneous and FG-CNTRC plates are conducted using the proposed method.Aspects such as boundary conditions,CNT volume fractions,geometric shapes,and width-to-thickness ratios are also discussed.Regular node arrangements and background meshes are adopted in the present study.Results are computed using different scalar parameters and numbers of nodes.Convergence properties for the central deflection of isotropic plates are analyzed in terms of the number of nodes and different scalar parameters.The normalized central deflection is defined and examined under various boundary conditions.展开更多
Hydrogen evolution reaction(HER)in acidic media has been spotlighted for hydrogen production since it is a favourable kinetics with the supplied protons from a counterpart compared to that within alkaline environment....Hydrogen evolution reaction(HER)in acidic media has been spotlighted for hydrogen production since it is a favourable kinetics with the supplied protons from a counterpart compared to that within alkaline environment.However,there is no choice but to use a platinum-based catalyst yet.As for a noble metal-free electrocatalyst,incorporation of earth-abundant transition metal(TM)atoms into nanocarbon platforms has been extensively adopted.Although a data-driven methodology facilitates the rational design of TM-anchored carbon catalysts,its practical application suffers from either a simplified theoretical model or the prohibitive cost and complexity of experimental data generation.Herein,an effective and facile catalyst design strategy is proposed based on machine learning(ML)and its model verification using electrochemical methods accompanied by density functional theory simulations.Based on a Bayesian genetic algorithm ML model,the Ni-incorporated carbon quantum dots(Ni@CQD)loaded on a three-dimensional reduced graphene oxide conductor are proposed as the best HER catalyst amongst the various TM-incorporated CQDs under the optimal conditions of catalyst loading,electrode type,and temperature and pH of electrolyte.The ML results are validated with electrochemical experiments,where the Ni@CQD catalyst exhibited superior HER activity,requiring an overpotential of 151 mV to achieve 10 mAcm^(−2) with a Tafel slope of 52 mV dec^(−1) and impressive durability in acidic media up to 100 h.This methodology can provide an effective route for the rational design of highly active electrocatalysts for commercial applications.展开更多
文摘Lithium-ion capacitors(LICs)combine the high power dens-ity of electrical double-layer capacitors with the high energy density of lithium-ion batteries.However,they face practical limitations due to the narrow operating voltage window of their activated carbon(AC)cathodes.We report a scalable thermal treatment strategy to develop high-voltage-tolerant AC cathodes.Through controlled thermal treatment of commer-cial activated carbon(Raw-AC)under a H_(2)/Ar atmosphere at 400-800℃,the targeted reduction of degradation-prone functional groups can be achieved while preserving the critical pore structure and increasing graph-itic microcrystalline ordering.The AC treated at 400℃(HAC-400)had a significant increase in specific capacity(96.0 vs.75.1 mAh/g at 0.05 A/g)and better rate capability(61.1 vs.36.1 mAh/g at 5 A/g)in half-cell LICs,along with an 83.5%capacity retention over 7400 cycles within an extended voltage range of 2.0-4.2 V in full-cell LICs.Scalability was demonstrated by a 120 g batch production,enabling fabrication of pouch-type LICs with commercial hard carbon anodes that delivered a higher energy density of 28.3 Wh/kg at 1 C,and a peak power density of 12.1 kW/kg compared to devices using raw AC.This simple,industry-compatible approach may be used for producing ad-vanced cathode materials for practical high-performance LICs.
文摘Functional carbon-based materials have become a key research direction in the field of advanced electrocatalysis due to their unique structure and properties.Various strategies have been proposed to design and synthesize high-performance carbon-based electrocatalysts.In this review,we comprehensively summarize the latest developments in carbon-based materials for advanced electrocatalysis,with particular emphasis on the structure design strategies and the intrinsic relationship between structure,activity,and performance.The functionalization of multi-dimensional carbon-based materials with enhanced electrocatalytic performance is first addressed.Next,the impact of electronic and structural engineering on the performance of carbon-based materials for electrocatalysis is discussed in terms of the advantages of different types of carbon-based materials in electrocatalytic applications.Finally,the prospects in areas such as precise tuning of functional carbon-based materials,the development of renewable carbon materials,the use of advanced characterization techniques and the promotion of smart manufacturing and responsiveness are high-lighted.
基金supported by the National Science Foundation of China(No.21606191)the Natural Science Foundation of Shandong Province(No.ZR2020ME024).
文摘As a new electrochemical technology,capacitive deionization(CDI)has been increasingly applied in environmental water treatment and seawater desalination.In this study,functional groups modified porous hollow carbon(HC)were synthesized as CDI electrode material for removing Na^(+)and Cl^(−)in salty water.Results showed that the average diameter of HC was approximately 180 nm,and the infrared spectrum showed that its surface was successfully modified with sulfonic and amino groups,respectively.The sulfonic acid functionalized HC(HC-S)showed better electrochemical and desalting performance than the amino-functionalized HC(HC–N),with a maximum Faradic capacity of 287.4 F/g and an adsorptive capacity of 112.97 mg/g for NaCl.Additionally,92.63%capacity retention after 100 adsorption/desorption cycles demonstrates the excellent stability of HC-S.The main findings prove that HC-S is viable as an electrodematerial for desalination by high-performance CDI applications.
基金supported by National Natural Science Foundation of China(U21B2057)。
文摘Vanadium redox flow batteries(VRFBs)hold significant promise for large-scale energy storage applications.However,the sluggish reaction kinetics on the electrode surface considerably limit their performance.Implementation of efficient surface modification on carbon electrodes through an economically viable production method is crucial for the practical application of VRFBs.Herein,a nano-carbon layer with morphology of fine nanoparticles(<90 nm)and rich oxygen functional groups was constructed on carbon felts by unbalanced magnetron sputtering coupled with thermal treatment.This modified carbon felt served as both anode and cathode in cell,enabling an improved wettability of electrolyte and high reversibility of the active mass,and promoted kinetics of redox reactions.The optimized carbon felt,achieved through one hour of deposition(1C-CF),demonstrated outstanding electrochemical performance in a single cell.The cell exhibited a high energy efficiency of 82.4%at a current density of 100 m A cm^(-2)and maintained 71.8%at a high current density of 250 mA cm^(-2).Furthermore,the energy efficiency remained at 77.2%during long-term cycling(450 cycles)at a current density of 150 mA cm^(-2),indicating good electrode stability.Our results shed light on the surface design of carbon felt electrodes for the broad application interest of VRFB energy storage systems.
基金supported by the Open Research Fund of Jiangxi Provincial Academy of Water Resources Sciences(2022SKTR05&2022SKTR03)the National Natural Science Foundation of China(42067049&42367049),the Jiangxi Provincial Natural Science Foundation(20242BAB25350)+5 种基金the Research Project of the Jiangxi Provincial Department of Forestry(CXZX(2025)14 and JXTG(2023)15)the Ganpo Juncai Plan(QN2023018)the Ganpo Yingcai Plan(gpyc20240038)the Double Thousand Plan of Jiangxi Province(jxsq2023102213 and jxsq2023102214)the Jiangxi Province“Science and Technology+Water Resources”Joint Plan Project(2023KSG01001)the Major Discipline Academic and Technical Leaders Training Program of Jiangxi Province(20243BCE51025).
文摘Stable carbon isotopes(δ^(13)C)are extensively utilized to study intrinsic water use efficiency(iWUE)at the leaf-scale in terrestrial ecosystems,serving as a crucial metric for assessing plant adaptation to climate change.However,there is currently a lack of consensus regarding the leaf-scale iWUE variation characteristics among different functional types.In this study,we measured theδ^(13)Cleaf and iWUE values of different functional plants(i.e.,life forms,leaf types,and mycorrhizal types)from 120 species across distinct habitat types(i.e.,hillside,nearpeak,and peak)in a subtropical forest on the western slope of Wuyi Mountains,southern China.The results showed that theδ^(13)Cleaf values of plants on the western slope of Wuyi Mountains ranged from-34.63‰to-30.04‰,and iWUE ranged from 5.93μmol mol^(-1)to 57.34μmol mol^(-1).Theδ^(13)Cleaf and iWUE values differed significantly among plant life forms,following the order of herbs>vine plants>shrubs>trees.Theδ^(13)Cleaf and iWUE values of ectomycorrhizal(ECM)species were greater than those of arbuscular mycorrhizal(AM)species despite there being no significant difference between plants with different leaf types(Simple leaves(SL)vs.Compound leaves(CL)).From the hillside to the peak,both at the community level and at the species level,theδ^(13)C values of leaves and iWUE values of plants exhibited an upward trend.The regression analysis revealed that leaf-scale iWUE was significantly negatively correlated with soil water content and significantly positively correlated with leaf phosphorus content.The findings indicated that leaf carbon isotope fractionation and corresponding iWUE can be influenced by life form,mycorrhizal type,and soil water availability.These insights provide a deeper understanding of the coupling mechanisms of carbon,water,and nutrients among different functional plant types in subtropical forests,and offer insights into predicting plant adaptability under climate change.
文摘Amino acids are the building blocks of proteins and play vital roles in both biological systems and drug development.In recent years,increasing attention has been given to the functionalization of amino acid derivatives.Since the introduction of therapeutic insulin in the early 20th century,the conjugation of drug molecules with amino acids and peptides has been pivotal in driving advancements in drug discovery and become an integral part of modern medical practice.Currently,over a hundred peptide-drug conjugates have received global approval and are widely used to treat diseases such as diabetes,cancer,chronic pain,and multiple sclerosis.Key technologies for conjugating peptides with bioactive molecules include antibody-drug conjugates(ADCs),peptide-drug conjugates(PDCs),and proteolysis targeting chimeras(PROTACs).Significant efforts have been dedicated to developing strategies for the modification of amino acids and peptides,with particular focus on site-selective C-H alkylation/arylation reactions.These reactions are crucial for synthesizing bioactive molecules,as they enable the precise introduction of functional groups at specific positions,thereby improving the pharmacological properties of the resulting compounds.
基金supported by the Natural Science Foundation of Shandong Province(No.ZR2022QE076)the National Natural Science Foundation of China(No.52202092)。
文摘The over-exploitation of fossil fuel energy has brought about serious environmental problems.It would be of great significance to construct efficient energy conversion and storage system to maximize utilize renewable energy,which contributes to reducing environmental hazards.For the past few years,in terms of electrocatalysis and energy storage,carbon fiber materials show great advantages due to its outstanding electrical conductivity,good flexibility and mechanical property.As a simple and low-cost technique,electrospinning can be employed to prepare various nanofibers.It is noted that the functional fiber materials with different special structure and composition can be obtained for energy conversion and storage by combining electrospinning with other post-processing.In this paper,the structural design,controllable synthesis and multifunctional applications of electrospinning-derived functional carbon-based materials(EFCMs)is reviewed.Firstly,we briefly introduce the history,basic principle and typical equipment of electrospinning.Then we discuss the strategies for preparing EFCMs with different structures and composition in detail.In addition,we show recently the application of advanced EFCMs in energy conversion and storage,such as nitrogen species reduction reaction,CO_(2) reduction reaction,oxygen reduction reaction,water-splitting,supercapacitors and ion batteries.In the end,we propose some perspectives on the future development direction of EFCMs.
基金supported by the National Natural Science Foundation of China(Nos.52370110 and 21607044)supported by the Fundamental Research Funds for the Central Universities(No.2023MS146)the Open Research Fund of the School of Chemistry and Chemical Engineering,Henan Normal University for support(Nos.2020ZD01 and 2021YB07)。
文摘Mercury ion(Hg^(2+)),as one of the most toxic heavy metal ions,accumulates easily in the environment,which can generate potential hazards to the ecosystem and human health.To effectively detect and remove Hg^(2+),we fabricated four types of carbon dots(CDs)using carboxymethyl nanocellulose as a carbon source doped with different elements using a hydrothermal method.All the CDs exhibited a strong fluorescence emission,excitation-dependent emission and possessed good water dispersibility.Moreover,the four fluorescent CDs were used for Hg^(2+)recognition in aqueous solution,where the CDs-N exhibited better sensitivity and selectivity for Hg^(2+)detection,with a low limit of detection of 8.29×10^(-6)mol/L.It was determined that the fluorescence quenching could be ascribed to a photoinduced charge-transfer processes between Hg^(2+)and the CDs.In addition,the CDs-N were used as a smart invisible ink for anticounterfeiting,information encryption and decryption.Furthermore,the CDs-N were immersed into a cellulose(CMC)-based hydrogel network to prepare fluorescent hydrogels capable of simultaneously detecting and adsorbing Hg^(2+).We anticipate that this research will open possibilities for a green method to synthesize fluorescent CDs for metal ion detection and fluorescent ink production.
文摘The chemical compound 3-(N-ethylamino)isobutyl)trimethoxysilane(EAMS)modified titanium dioxide(TiO_(2)),producing EAMS-TiO_(2),which was encased in graphitic carbon nitride(GCN)and integrated into epoxy resin(EP).The protective properties of mild steel coated with this nanocomposite in a marine environment were assessedusing electrochemical techniques.Thermogravimetric analysis(TGA)and Cone calorimetry tests demonstrated thatGCN/EAMS-TiO_(2)significantly enhanced the flame retardancy of the epoxy coating,reducing peak heat release rate(PHRR)and total heat release(THR)values by 88%and 70%,respectively,compared to pure EP.Salt spray testsindicated reduced water absorption and improved corrosion resistance.The optimal concentration of 0.6 wt%GCNEAMS/TiO_(2)yielded the highest resistance,with the nanocomposite achieving a coating resistance of 7.50×10^(10)Ω·cm^(2)after 28 d in seawater.The surface resistance of EP-GCN/EAMS-TiO_(2)was over 99.9 times higher than pure EP after onehour in seawater.SECM analysis showed the lowest ferrous ion dissipation(1.0 nA)for EP-GCN/EAMS-TiO_(2)coatedsteel.FE-SEM and EDX analyses revealed improved breakdown products and a durable inert nanolayered covering.Thenanocomposite exhibited excellent water resistance(water contact angle of 167°)and strong mechanical properties,withadhesive strength increasing to 18.3 MPa after 28 d in seawater.EP-GCN/EAMS-TiO_(2)shows potential as a coatingmaterial for the shipping industry.
基金supported by the National Natural Science Foundation(NSFC)of China(22179094)the research funding provided by Cangzhou Institute of Tiangong University(Grant No.TGCYY-Z-0202)
文摘Zn metal anodes are usually subject to grave dendrite growth during platting/stripping,which dramatically curtails the lifespan of aqueous Zn-ion batteries and capacitors.To address above problems,in our work,a novel phosphorus-functionalized multichannel carbon interlayer was designed and covered on Zn anodes.The results demonstrated that the multichannel structure combined with the three-dimensional meshy skeleton can provide more sufficient space for Zn deposition,thereby effectively inhibiting the growth of zinc dendrites.Meanwhile,theoretical calculations also confirmed that the P-C and P=O functional groups from phosphorus-functionalized multichannel carbon interlayer have the decisive influence in reducing the zinc nucleation potential and depositing uniformly zinc.Concretely,the symmetrical battery assembled with phosphorus-functionalized multichannel carbon interlayer-covered Zn anodes possessed a long lifetime of 3300 h at 2 mA cm^(-2)with 1 mAh cm^(-2).Furthermore,the full cell with activated carbon cathodes exhibited a high specific capacity of 80.5 mAh g^(-1)and outstanding cycling stability without capacity decay after 15000 cycles at a high current density of 5 A g^(-1).The superior electrochemical performance exceeded that of most reported papers.Consequently,our synthesized zincophilic interlayer with the unique structure has superior prospects for application in stabilizing zinc anodes and prolonging the lifespan of batteries.
基金supported by the National Natural Science Foundation of China(22179093 and21905202)。
文摘Aqueous zinc ion batteries are regarded as one of the most promising candidates for large-scale energy stor-age due to their high safety,cost-effectiveness,and environ-mental friendliness.However,uncontrolled zinc dendrite growth and side reactions of the zinc anode decrease the sta-bility of Zn batteries.We report the synthesis of an air-oxid-ized carbon nanotube(O-CNT)film by chemical vapor de-position followed by heat treatment in air which is used as a protective layer on the Zn foil to suppress zinc dendrite growth.The increase in the hydrophilicity of the O-CNT film caused by air oxidation facilitates zinc deposition between the film and the anode instead of deposition on the film surface.The porous structure of the O-CNT film homogenizes the Zn^(2+)ion flux and the electric field on the surface of the Zn foil,leading to the uniform deposition of Zn.As a result,a O-CNT@Zn symmetric cell has a much better cycling stability with a life of more than 3000 h at 1 mA cm^(−2) with a capacity of 1 mAh cm^(−2),and values of more than 2000 h and 1 mAh cm^(−2) at 5 mA cm^(−2).In addition,a O-CNT@Zn||Mn^(2+)inserted hydrated vanadium pentoxide(MnVOH)full cell has a better rate per-formance than a Zn||MnVOH cell,achieving a high discharge capacity of 194 mAh g^(−1) at a high current density of 8 A g^(−1).In a long-term cycling test,the O-CNT@Zn||MnVOH full cell has a capacity retention of 58.8%after 2000 cycles at a current density of 5 A·g^(−1).
基金supported by the National Key Research and Development Program of China[Grant No.2022YFD1500202]Strategic Priority Research Program of the Chinese Academy of Sciences[Grant No.XDA28020202]+1 种基金China Postdoctoral Science Foundation[Grant No.2024M753332]the RUDN University Strategic Academic Leadership Program.
文摘Partitioning of soil organic matter for particulate organic carbon(POC)and mineral-associated organic carbon(MAOC)is essential to understand carbon(C)storage under climate change,given their distinct properties and response to warming.The mechanisms underlying warming-induced changes in C pools in black soils(Mollisols)remain unknown,owing to the stability of C pools and the complexity of their associated microbial communities.This study elucidates POC and MAOC contents and their microbial controls in black soils along a mean annual temperature(MAT)gradient from 0.6 to 7.3℃.The POC content(3.3-17 g kg^(−1))increased with MAT,while MAOC content(33-60 g kg^(−1))decreased,indicating accelerated C turnover with warming.Higher MAT shifted the bacterial communities from K-to r-strategies,aligning with increased POC content.The dominance of r-strategists facilitated rapid utilization and mineralization of organic compounds(e.g.,mainly with low C/N ratio),reducing MAOC and increasing POC through sustained plant residue inputs.This shift towards r-strategists also corresponded with increased abundance of saprotrophic fungi and stronger bacteria-saprotrophic fungi associations.Warming in colder regions may release available organic matter that saprotrophic fungi preferentially utilize over plant residues to minimize energy expenditure,decreasing POC decomposition.Our findings suggest that integrating microbial r-/K-strategies help to elucidate these mechanisms and simplify the interpretation of temperature effects on the dynamics of two main functional pools of soil organic matter.
文摘Trees,mammals,and microbes relate to soil carbon(C)cycle.Trees capture C,and mammals consume plants and other animals,both contributing to organic remains that are then degraded by soil microbes.This organic C can be stored in soils or released into the atmosphere through microbial mineralization.Yet,the simultaneous effects of mammals and trees on C consumption by soil microbes have not been investigated.For 30 sampling sites in a mixed forest-savanna environment in southern Guyana,we jointly analyzed observational data of mammal and tree communities along with soil organic matter(SOM)composition(using Fourier transform infrared spectroscopy combined with attenuated total reflectance,energy dispersive X-ray fluorescence spectrometry,and CNH elemental analyzer)and soil microbial C consumption(using Biolog EcoPlates).It was found that higher mammal functional richness(FRic)and functional evenness(FEve)were related to reduced overall C consumption by soil microbes(for FRic:regression coefficient(β)=-0.010,standard error(SE)=0.005,P=0.034;for FEve:β=-0.012,SE=0.005,P=0.010)with the coefficient of determination(R^(2))value of 0.359,explaining 36%of the variance in average well color development values,whereas a higher tree richness was associated with a reduced diversity of C sources consumed by soil microbial communities(β=-0.353,SE=0.172,P=0.041)with the R2 value of 0.290,explaining 29%of the variance in Shannon diversity index values.Our results indicate that mammal and tree communities have complementary effects on soil microbial C consumption,improving our understanding of the functioning of C cycle in the high-diversity Amazon biome.These findings are crucial in elucidating the intricate connections between above-and belowground biodiversity that influence the accumulation and stabilization of soil organic C.
基金supported by Shanghai Science and Technology Plan Project(No.23ZR1467000)the Fundamental Research Funds for the Central University(No.22120240354)+1 种基金the National Natural Science Foundation of China(No.22131004)the Leading Scientific Research Project from China National Nuclear Corporation(No.CNNC–CXLM-202205).
文摘The efficient electrocatalytic nitrate(NO_(3)^(−))reduction to ammonia(NRA)offers a sustainable alternative for both environmental remediation and ammonia synthesis.Developing advanced electrocatalysts with rationally designed spatial arrangement of active sites and optimizing the synergetic effect among components are crucial for high efficiency and selectivity.Herein,we present Fe/N active sites decorated on porous carbon nanofibers(CNFs)with encapsulated FeCo nanoparticles(FeCo@CNFs-Fe/N)as electrocatalysts for NRA.The FeCo@CNFs-Fe/N catalyst demonstrates exceptional performance,achieving a high ammonia yield of 498.18μmol/(h·g_(cat)).Meanwhile,the enhanced reduction activity,especially the reduction in overpotential by 0.565 V,is 3–10 times higher than that of FeCo-encapsulated and Fe/N-modified CNFs-based catalysts.The enhanced catalytic activity is attributed to the efficient structure design and optimized spatial distribution of active sites,which enhance the electron transfer rate and decrease the reaction energy barrier.Mechanistic studies reveal that the synergetic effect between encapsulated nanoparticles and surface-modified Fe/N sites plays a crucial role in promoting efficient nitrate adsorption and selective ammonia production.These findings highlight the potential of strategically engineered CNF-based composites for nitrate reduction and other advanced electrocatalytic applications.
基金supported by the Open Project of Xiangjiang Laboratory (22XJ03026)the National Natural Science Foundation of China (72004060)+3 种基金the Provincial Natural Science Foundation of Hunan Province (2022JJ30015)the Scientific Research Project of Hunan Education Department, China (23A0457)Environmental Protection Scientific Research Project of Hunan Province (HBKT2021021)the “Digital-intelligence+” interdisciplinary research project of Hunan University of Technology and Business (2023SZJ22)
文摘The objective of this study was to identify and synthesize functional groups for the efficient adsorption of volatile organic compounds(VOCs)through a combination of theoretical calculations,molecular design,and experimental validation.The density functional theory(DFT)calculation,focusing on the P-containing functional groups,showed that methanol adsorption was dominated by the electrostatic interaction between the carbon surface and methanol,while toluene was mainly trapped through π-π dispersive interaction between toluene molecule and functional group structure.The experimental results showed the phosphorus-doped carbon materials(PCAC)prepared by directly activating potassium phytate had a phosphorus content of up to 4.5%(atom),mainly in the form of C-O-P(O)(OH)_(2).The material exhibited a high specific area(987.6m^(2)·g^(-1))and a large adsorption capacity for methanol(440.0 mg·g^(-1))and toluene(350.1 mg·g^(-1)).These properties were superior to those of the specific commercial activated carbon(CAC)sample used for comparison in this study.The adsorption efficiencies per unit specific surface area of PCAC were 0.45 mg·g^(-1) m^(-2) for methanol and 0.35 mg·g^(-1)·m^(-2) for toluene.This study provided a novel theoretical and experimental framework for the molecular design of polarized elements to enhance the adsorption of polar gases,offering significant advancements over existing commercial solutions.
基金supported by Yunnan Major Scientific and Technological Projects(No.202202AG050005)Yunnan Fundamental Research Projects(No.202101BE070001-001).
文摘The ACF adsorbent with high Cu loading was treated with dielectric barrier discharge plasma to mitigate the negative effects of high Cu loading and enhance PH_(3)and H_(2)S adsorption and oxidation.Bruno-Emmett-Taylor(BET)result showed that the specific surface area of the adsorbent after air plasma modification was almost three times that before modification.X-ray photoelectron spectroscopy(XPS)findings revealed that the amino group was added to the adsorbent's surface,increasing lattice oxygen and chemisorbed oxygen.The adsorbent's large specific surface area,excellent surface active oxygen,and abundance of basic groups facilitate PH_(3)and H_(2)S adsorption and oxidation.The scanning electron microscopy showed that air plasma modification exposed more active components and uniformly dispersed them on the surface of adsorbent,thereby improving the adsorption performance.Activity evaluation results showed that the adsorbent has the best ability to capture PH_(3)and H_(2)S after being modified by air plasma at 4 kV voltage for 10 min.The adsorbent's breakthrough ability at high space velocity(WHSV:60,000 h^(−1))is 190 mg P/g and 146 mg S/g,respectively,which is 74%and 60%greater than that before modification.This is a great improvement over previous studies.In addition,the possible mechanism of adsorbent deactivation was proposed.
基金supported by the National Natural Science Foundation of China(22278155,U23A6005)。
文摘Lignin-derived hard carbon shows potential as an anode material for sodium-ion batteries(SIBs)due to its high carbon content and aromatic structure,but its limited reversible adsorption sites and low conductivity hinder performance.This study introduces a self-activation strategy to optimize carbon layer stacking and surface functional groups in microporous carbon,significantly enhancing sodium storage capacity and rate performance.By utilizing oxygen-containing functional groups in organic solvent lignin,we induce micropore formation during pyrolysis,effectively regulating graphite domains and closed pores structures without disrupting carbon layer growth.Unstacked graphene layers serve as efficient electron transport channels and expose additional adsorption sites,simultaneously increasing sodium storage capacity and intrinsic conductivity.The resultant S-OLHC demonstrates a remarkable sodium storage capacity of 358 mA h/g at 0.05 A/g after 200 cycles and maintains 231 mA h/g after 1000 cycles at 2 A/g.This strategy eliminates the need for additional pore-forming agents,offering a simpler,more efficient,and environmentally friendly approach compared to traditional activation methods.This work advances the rational design of high-performance biomass-derived hard carbon for SIBs by leveraging inherent structural characteristics and provides a sustainable low-carbon strategy for lignin valorization in renewable energy storage.
文摘A tree's basal area(BA)and wood volume scale exponentially with tree diameter in species-specifc patterns.Recent observed increases in tree growth suggest these allometric relationships are shifting in response to climate change,rising CO_(2) levels,and/or changes in forest management.We analyzed 9,214 cores from nine conifer and 11 broadleaf species grown in managed mixed-species stands in the upper Midwest to quantify how well diameter(diameter at breast height(DBH))serves to predict BA growth and above-ground wood and carbon(C).These samples include many large trees.We ft mixed models to predict BA growth and above-ground biomass/C from diameter,tree height,and the BA of nearby trees while controlling for site effects.Models account for 55%–83%of the variance in log(recent growth),improving predictions over earlier models.Growth-diameter scaling exponents covary with certain leaf and stem(but not wood)functional traits,reflecting growth strategies.LogBA increment scales linearly with log(diameter)as trees grow bigger in 16/20 species and growth actually accelerates in Quercus rubra L.Three other species plateau in growth.Growth only decelerates in red pine,Pinus resinosa Ait.Growth in whole-tree,above-ground biomass,and C accelerate even more strongly with diameter(mean exponent:2.08 vs.1.30 for BA growth).Sustained BA growth and accelerating wood/C growth contradict the common assumption that tree growth declines in bigger trees.Yield tables and silvicultural guidelines should be updated to reflect these current relationships.Such revisions will favor delaying harvests in many managed stands to increase wood production and enhance ecosystem values including C fxation and storage.Further research may resolve the relative roles of thinning,climatic conditions,nitrogen inputs,and rising CO2 levels on changing patterns of tree growth.
基金supported by the National Natural Science Foundation of China(No.52374110)Key scientific and technological projects of Henan province(No.242102320337)Basic Research Fund of Zhongyuan University of Technology(No.K2022QN008).
文摘A mesh-free method is presented to investigate the static bending properties of functionally graded carbon nanotube-reinforced composite(FG-CNTRC)plates.The curvature of the plate is directly interpolated with the nodal deflections due to the higher-order continuity property of the moving leastsquares approximation,establishing a mesh-free computational scheme where the nodal deflections are the only unknowns.The convergence and efficiency of the proposed method are studied based on a homogeneous square plate.The FG-CNTRC plates are modeled with continuously varying Young’s moduli along the thickness direction according to the volume fraction of the carbon nanotubes(CNTs).Detailed studies have been conducted on the effects of different boundary conditions,CNT volume fractions,geometric shapes,and width-to-thickness ratios on bending behavior.CNT efficiency parameters are introduced to account for load transfer between the nanotubes and the matrix,treating the nanocomposites as orthotropic materials.However,in the actual structure,arranging the CNTs in the desired direction is more difficult compared to other fibers.Therefore,in the present study,CNTs in the composites are considered to be arranged randomly,resulting in the composite properties being treated as isotropic.The study includes second-order derivatives of deflections,and the finite element method typically requires C1 continuity for interpolation,which introduces challenges in building elements and constructing interpolation functions.The distinct advantage of the mesh-free method is that it requires only C0 weight functions.A mesh-free computational scheme based on moving leastsquares approximations for composite plates using Kirchhoffplate theory is established.Bending analyses of homogeneous and FG-CNTRC plates are conducted using the proposed method.Aspects such as boundary conditions,CNT volume fractions,geometric shapes,and width-to-thickness ratios are also discussed.Regular node arrangements and background meshes are adopted in the present study.Results are computed using different scalar parameters and numbers of nodes.Convergence properties for the central deflection of isotropic plates are analyzed in terms of the number of nodes and different scalar parameters.The normalized central deflection is defined and examined under various boundary conditions.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(NRF-2022R1A2C1011559,No.RS-2024-00405818 and NRF-2021M3H4A6A01045764)by the National Supercomputing Center with supercomputing resources including technical support(KSC-2024-CRE-0196)by Korea Basic Science Institute(National Research Facilities and Equipment Center)grant funded by the Ministry of Science and ICT(No.RS-2024-00404712).
文摘Hydrogen evolution reaction(HER)in acidic media has been spotlighted for hydrogen production since it is a favourable kinetics with the supplied protons from a counterpart compared to that within alkaline environment.However,there is no choice but to use a platinum-based catalyst yet.As for a noble metal-free electrocatalyst,incorporation of earth-abundant transition metal(TM)atoms into nanocarbon platforms has been extensively adopted.Although a data-driven methodology facilitates the rational design of TM-anchored carbon catalysts,its practical application suffers from either a simplified theoretical model or the prohibitive cost and complexity of experimental data generation.Herein,an effective and facile catalyst design strategy is proposed based on machine learning(ML)and its model verification using electrochemical methods accompanied by density functional theory simulations.Based on a Bayesian genetic algorithm ML model,the Ni-incorporated carbon quantum dots(Ni@CQD)loaded on a three-dimensional reduced graphene oxide conductor are proposed as the best HER catalyst amongst the various TM-incorporated CQDs under the optimal conditions of catalyst loading,electrode type,and temperature and pH of electrolyte.The ML results are validated with electrochemical experiments,where the Ni@CQD catalyst exhibited superior HER activity,requiring an overpotential of 151 mV to achieve 10 mAcm^(−2) with a Tafel slope of 52 mV dec^(−1) and impressive durability in acidic media up to 100 h.This methodology can provide an effective route for the rational design of highly active electrocatalysts for commercial applications.
