Vanadium redox flow batteries(VRFBs)are a means of large-scale energy storage due to their excellent scalability,safety,long cycling life,and decoupled power and energy capacities.However,the slow redox kinetics of va...Vanadium redox flow batteries(VRFBs)are a means of large-scale energy storage due to their excellent scalability,safety,long cycling life,and decoupled power and energy capacities.However,the slow redox kinetics of vanadium species on conventional carbon electrodes remains a major limitation to their performance.We investigated the deposition of carbon black,carbon nanotubes,and electrochemically exfoliated graphene(Exf-Gr)onto thermally-activated carbon paper(ACP)by spray coating to increase the electrode electrocatalytic activity.The modified electrodes were characterized using scanning electron microscopy,X-ray diffraction,Raman spectroscopy,X-ray photoelectron microscopy,and surface area analysis,while their electrochemical properties were evaluated by cyclic voltammetry,electrochemical impedance spectroscopy,and singlecell VRFB testing.Among the modified electrodes,Exf-Gr/ACP had the best performance,achieving a 2.9-fold reduction in charge transfer resistance compared to pristine ACP and delivering 2.5 times the discharge capacity in single-cell tests.This improvement is attributed to Exf-Gr’s high surface area,favorable catalytic activity,and excellent dispersion on the ACP substrate.Surface modification with electrochemically exfoliated graphene is a highly effective strategy for improving the electrode performance in VRFB systems,with significant implications for large-scale energy storage.展开更多
Carbon superstructures with multiscale hierarchies and functional attributes represent an appealing cathode candidate for zinc hybrid capacitors,but their tailor-made design to optimize the capacitive activity remains...Carbon superstructures with multiscale hierarchies and functional attributes represent an appealing cathode candidate for zinc hybrid capacitors,but their tailor-made design to optimize the capacitive activity remains a confusing topic.Here we develop a hydrogen-bond-oriented interfacial super-assembly strategy to custom-tailor nanosheet-intertwined spherical carbon superstructures(SCSs)for Zn-ion storage with double-high capacitive activity and durability.Tetrachlorobenzoquinone(H-bond acceptor)and dimethylbenzidine(H-bond donator)can interact to form organic nanosheet modules,which are sequentially assembled,orientally compacted and densified into well-orchestrated superstructures through multiple H-bonds(N-H···O).Featured with rich surface-active heterodiatomic motifs,more exposed nanoporous channels,and successive charge migration paths,SCSs cathode promises high accessibility of built-in zincophilic sites and rapid ion diffusion with low energy barriers(3.3Ωs-0.5).Consequently,the assembled Zn||SCSs capacitor harvests all-round improvement in Zn-ion storage metrics,including high energy density(166 Wh kg-1),high-rate performance(172 m Ah g^(-1)at 20 A g^(-1)),and long-lasting cycling lifespan(95.5%capacity retention after 500,000 cycles).An opposite chargecarrier storage mechanism is rationalized for SCSs cathode to maximize spatial capacitive charge storage,involving high-kinetics physical Zn^(2+)/CF_(3)SO_(3)-adsorption and chemical Zn^(2+)redox with carbonyl/pyridine groups.This work gives insights into H-bond-guided interfacial superassembly design of superstructural carbons toward advanced energy storage.展开更多
Carbon-based materials have gained significant attention in anticancer treatment because of their exceptional biocompatibility,yet critical challenges persist in establishing definitive correlations between their poro...Carbon-based materials have gained significant attention in anticancer treatment because of their exceptional biocompatibility,yet critical challenges persist in establishing definitive correlations between their porous structures and functional performance.We report the use of a silica template to guide pore formation in the design of mesoporous carbon spheres(mC)with tailored pore structures for improved combined photothermal-chemotherapy.The mesopore size of mC has been adjusted by kinetic control of the resin polymerization and silica hydrolysis.Structural characterization showed that 4.4 nm mesopores enabled an exceptional gemcitabine loading of 228 mg g^(−1) and a sustained pH/thermal dual-responsive release with>70%drug release under near-infrared(NIR)irradiation.Finite element analysis demonstrated pore size-dependent heat transfer dynamics,with the improved mC achieving a superior photothermal conversion efficiency of 62%by a combination of N-doping and defect engineering.In vitro evaluations confirmed outstanding biocompatibility with>95%cell viability at 200μg mL^(−1) and potent tumor suppression in pancreatic and biliary cancer models with an~5%cell viability at 25μg mL^(−1) where combined therapy showed a 3.7-fold increased cytotoxicity over monotherapy.The improved structure of mC facilitated cascade therapeutic effects with enhanced tumor permeability derived from NIR-triggered hyperthermia and prolonged therapeutic exposure due to pH-responsive drug release.This pore engineering strategy establishes a structure-function process for next-generation theranostic platforms,addressing the critical limitations of conventional pancreatic and biliary cancer therapies through spatiotemporal control of multimodal treatment.展开更多
CO_(2) capture and utilization(CCU)technologies have been recognized as crucial strategies for mitigating global warming,reducing carbon emission,and promoting resource circularity.As such,the design and development o...CO_(2) capture and utilization(CCU)technologies have been recognized as crucial strategies for mitigating global warming,reducing carbon emission,and promoting resource circularity.As such,the design and development of related materials have attracted considerable research attention.Carbon-based materials,characterized by tunable pore structures,abundant active sites,high specific surface area,and excellent chemical stability,demonstrate significant potential for applications in CO_(2) capture and utilization.This review systematically analyzes the adsorption behaviors and performance variations of typical carbon materials,including activated carbon,porous carbon,graphene,and carbon nanotubes during CO_(2) capture processes.Concerning CO_(2) utilization,emphasis is placed on recent advances in the catalytic applications of carbon-based materials in key reactions such as methanation,reverse water-gas shift,dry reforming of methane,and alcohol synthesis.Moreover,the benefits and drawbacks of carbon materials in terms of CO_(2) adsorption capacity,catalytic activity,and stability are thoroughly evaluated,and their potential applications in integrated CO_(2) capture and utilization technologies are discussed.Finally,key strategies for enhancing the performance of carbonaceous materials through structural modulation and surface modification are elucidated.This review aims to provide theoretical guidance for the future development and large-scale implementation of carbon-based materials in CCU technologies.展开更多
Nanoporous carbon materials were synthesized from asphaltenes using a thermo-chemical treatment under an inert atmosphere and in-situ KOH activation.N-doping was also employed in certain samples to reveal the impact o...Nanoporous carbon materials were synthesized from asphaltenes using a thermo-chemical treatment under an inert atmosphere and in-situ KOH activation.N-doping was also employed in certain samples to reveal the impact of nitrogen on the properties of materials.The synthesized materials were fully characterized to disclose their textural properties,structural parameters,surface functional groups,elemental compositions,and morphologies.Textural property analysis revealed a remarkable increase in surface areas after alkaline treatment(~1500-2000 m^(2)/g),which was mainly ascribed to the formation of micro-and mesopores.The measurements of structural parameters endorse and complement the findings on textural properties.The asphaltene-derived porous carbons have been employed in energy storage and carbon capture applications.The materials exhibit specific capacitances ranging from 130 to 180 F/g at 0.2 A/g in a 3 M KOH.These results suggest that nitrogen doping significantly enhances the pseudocapacitive behavior of the electroactive materials by promoting Fara-daic redox reactions and improving ion diffusion and adsorption rates.Asphaltene-derived porous carbons also exhibit notable CO_(2)adsorption capacities of 3-4 mmol/g at 25◦C and 1 bar.Also,breakthrough experiments confirm that the N-doped material exhibits remarkable stability,reusability,and increased surface basicity,achieving an impressive CO_(2)uptake of 0.446 mmol/g.These results highlight the potential of asphaltene-based porous carbons as efficient materials for carbon capture and energy storage applications.展开更多
Despite their high theoretical capacity and energy density,lithiumsulfur(Li–S)batteries still face challenges such as soluble lithium polysulfides(LiPSs)shuttling and sluggish redox kinetics.In this work,we used a no...Despite their high theoretical capacity and energy density,lithiumsulfur(Li–S)batteries still face challenges such as soluble lithium polysulfides(LiPSs)shuttling and sluggish redox kinetics.In this work,we used a novel MoS_(2)-Mo_(2)C heterostructure anchored on a carbon sponge(CS)as a Li_(2)S host to solve these problems.A simple hydrothermal process following carbothermal reduction was used to construct the MoS_(2)-Mo_(2)C heterostructure,enabling control of the phases and integration of MoS_(2) and Mo_(2)C.Structural characterization confirmed the coherent interface of the heterostructure with a precise orientation relationship between the two phases and their uniform distribution.An evaluation of the adsorption and catalytic performance of the material showed that it has an exceptional LiPSs adsorption capacity with faster conversion from Li_(2)S_(4) to Li_(2)S_(2).Density functional theory calculations further confirmed these results.As a result,the cathode had a high initial discharge capacity of 693 mAh g^(−1) at 0.2 C and achieved stable cycling at 2 C for 500 cycles with a low decay rate of 0.107%per cycle.The heterostructure design,coupled with the macroporous CS framework,effectively prevented the shuttling and increased sulfur utilization,offering a promising way to produce practical high-energydensity Li–S batteries.展开更多
The rice ratooning system has attracted increasing attention in southern China due to its low carbon emissions and high yield potential.However,the net carbon budget and underlying mechanisms remain unclear.Three rice...The rice ratooning system has attracted increasing attention in southern China due to its low carbon emissions and high yield potential.However,the net carbon budget and underlying mechanisms remain unclear.Three rice cropping systems were established in this trial experiment conducted from 2021 to 2022 in Fuzhou(25°05'N,119°13'E),Southeast China:ratooning rice(RR:MC+RSR)pattern for rice ratooning,single-cropping rice(LR_(1)),and double-cropping rice(DC:ER+LR_(2)).The closed static dark box gas collection,dry matter determination,life cycle assessment(LCA)etc.approaches were utilized to investigate the mechanism of“high carbon fixation–low emissions”mechanism in RR.A comprehensive assessment was conducted across multiple dimensions,including crop yield,greenhouse gas(GHG)emissions,carbon and nitrogen footprints,resource use efficiency,carbon sequestration capacity,and carbon budget balance.Results showed that the average daily yield of ratoon season rice(RSR)across RR treatments from 2021 to 2022 was 28.21–47.40%higher than that of the main crop(MC)and LR_(1),and the average daily yield of RR was 13.50–27.76%higher than DC.This yield advantage was attributed to a 32.32–39.26%increase in the allocation of^(13)C-labeled photosynthetic products(including non-structural carbohydrates,NSCs)to panicle organs,and a 21.77–43.51%reduction in allocation to underground roots and soil.Furthermore,the average daily global warming potential(GWP)was 16.44 kg CO_(2)-eq ha^(–1)for RR,24.99 kg CO_(2)-eq ha^(–1)for LR_(1),and 21.32 kg CO_(2)-eq ha^(–1)for DC.Specifically,the average daily GWP of ratoon rice was 34.21%lower than that of LR_(1) and 22.90%lower than double-cropping rice.Similarly,the average daily greenhouse gas intensity(GHGI)of ratoon rice was 62.28%lower than LR_(1) and 28.96%lower than double-cropping rice.In terms of carbon and nitrogen footprints,the ratoon rice system exhibited average daily values of 34.54 kg CO_(2)-eq ha^(–1)and 0.47 kg N ha^(–1),respectively.In comparison,LR_(1) had values of 45.63 kg CO_(2)-eq ha^(–1)and 0.49 kg N ha^(–1),while double-cropping rice showed 43.38 kg CO_(2)-eq ha^(–1)and 0.53 kg N ha^(–1).These values represent reductions of 24.30%in carbon footprint and4.28%in nitrogen footprint relative to LR_(1),and 20.38 and 11.45%relative to double-cropping rice,respectively.Moreover,the average annual carbon budget surplus across systems was 22,380.01 kg CO_(2)-eq ha^(–1)for ratoon rice(MC+RSR),11,228.54 kg CO_(2)-eq ha^(–1)for LR_(1),and 23,772.15 kg CO_(2)-eq ha^(–1)for DC.Consequently,the resource utilization efficiency of the RR was 24.42 and 47.50%higher than that of single-cropping and double-cropping systems,respectively.Average daily economic returns also increased by 32.71 and 80.75%,respectively.These findings provide a robust theoretical foundation and practical guidance for advancing agricultural carbon neutrality technologies and ensuring food security.展开更多
To elucidate the effect of calcite-regulated activated carbon(AC)structure on low-temperature denitrification performance of SCR catalysts,this work prepared a series of Mn-Ce/De-AC-xCaCO_(3)(x is the calcite content ...To elucidate the effect of calcite-regulated activated carbon(AC)structure on low-temperature denitrification performance of SCR catalysts,this work prepared a series of Mn-Ce/De-AC-xCaCO_(3)(x is the calcite content in coal)catalysts were prepared by the incipient wetness impregnation method,followed by acid washing to remove calcium-containing minerals.Comprehensive characterization and low-temperature denitrification tests revealed that calcite-induced structural modulation of coal-derived AC significantly enhances catalytic activity.Specifically,NO conversion increased from 88.3%of Mn-Ce/De-AC to 91.7%of Mn-Ce/De-AC-1CaCO_(3)(210℃).The improved SCR denitrification activity results from the enhancement of physicochemical properties including higher Mn^(4+)content and Ce^(4+)/Ce^(3+)ratio,an abundance of chemisorbed oxygen and acidic sites,which could strengthen the SCR reaction pathways(richer NH_(3)activated species and bidentate nitrate active species).Therefore,NO removal is enhanced.展开更多
Porous carbon microspheres are widely regarded as a superior CO_(2) adsorbent due to their exceptional efficiency and affordability.However,better adsorption performance is very attractive for porous carbon microspher...Porous carbon microspheres are widely regarded as a superior CO_(2) adsorbent due to their exceptional efficiency and affordability.However,better adsorption performance is very attractive for porous carbon microspheres.And modification of the pore structure is one of the effective strategies.In this study,multi-cavity mesoporous carbon microspheres were successfully synthesized by the synergistic method of soft and hard templates,during which a phenolic resin with superior thermal stability was employed as the carbon precursor and a mixture of silica sol and F108 as the mesoporous template.Carbon microspheres with multi-cavity mesoporous structures were prepared,and all the samples showed highly even mesopores,with diameters around 12 nm.The diameter of these microspheres decreased from 396.8 nm to about 182.5 nm with the increase of silica sol.After CO_(2) activation,these novel carbon microspheres(APCF0.5-S1.75)demonstrated high specific surface area(983.3 m^(2)/g)and remarkable CO_(2) uptake of 4.93 mmol/g at 0℃ and1 bar.This could be attributed to the unique multi-cavity structure,which offers uniform mesoporous pore channels,minimal CO_(2) transport of and a greater number of active sites for CO_(2) adsorption.展开更多
Photocatalysis is one of the most promising technologies for solving environmental and energy problems,but current photocatalysts still suffer from low visible light utilization and insufficient photogenerated charge ...Photocatalysis is one of the most promising technologies for solving environmental and energy problems,but current photocatalysts still suffer from low visible light utilization and insufficient photogenerated charge separation efficiency.Therefore,in this work,D-A tubular materials with tubular carbon nitride(TCN)as electron donor(D)and 2-mercaptobenzothiazole(BZ)as electron acceptor(A)were constructed by molecular doping and modulation of the carbon nitride geometry.It was shown that the introduction of BZ could modulate the electronic structure of the catalyst,promote electron migration from TCN to BZ,and inhibit the recombination of photogenerated electrons and holes.Meanwhile,the ultra-thin tubular structure could expose more active sites.In addition,the adsorption of protons by BZ-TCN was further improved due to the modulation of the charge distribution between the components by the introduction of small molecules.Among them,the photocatalytic hydrogen production rate of BZ_(0.1)-TCN was twice that of TCN.The in-depth discussion of the components through theoretical calculations and characterization tests contributes to the understanding of the mechanism of photocatalytic hydrogen production.展开更多
This study investigated the efficient conversion of greenhouse gases(GHGs),CO_(2)and CH_(4)mixtures,into few-walled carbon nanotubes(FWCNTs)through an optimized single-step and dual-step chemical vapor deposition(CVD)...This study investigated the efficient conversion of greenhouse gases(GHGs),CO_(2)and CH_(4)mixtures,into few-walled carbon nanotubes(FWCNTs)through an optimized single-step and dual-step chemical vapor deposition(CVD)process.In the single-step process for directly synthesizing FWCNTs from greenhouse gases,CO_(2)concentration,gas flowrates,and H_(2)addition were identified as factors influencing the growth of FWCNTs.It was demonstrated that minimizing the amounts of CO_(2)and H_(2)was essential for achieving complete CO_(2)conversion because CO_(2)acts as an oxidizing agent that hinders CNT growth,while an excess of H_(2)disrupts the chemical equilibrium of the CO_(2)conversion reaction,leading to side reactions that suppress FWCNTs formation.To overcome these limitations,a dual-step approach incorporating sequential catalytic reactions was developed.In the first step,the Ni/SiO_(2)catalyst was utilized to facilitate CO_(2)methanation,reducing CO_(2)amounts while generating CH_(4)-rich gas.In the second step,CH_(4)pyrolysis was performed over the FeMo/MgO catalyst,enabling the growth of high-quality FWCNTs.This sequential configuration successfully synthesized FWCNTs under conditions previously unattainable in the single-step process,validating the effectiveness of the dual-step design.The strategic optimization of process parameters and sequential catalytic reactions established a viable route for converting GHGs into valuable FWCNTs.展开更多
Assessing the carbon sink potential of marine aquaculture is critical to fostering sustainable marine economic development and achieving carbon neutrality.This study evaluates the carbon sink potential of four nearsho...Assessing the carbon sink potential of marine aquaculture is critical to fostering sustainable marine economic development and achieving carbon neutrality.This study evaluates the carbon sink potential of four nearshore aquaculture systems in China:floating raft,net cage,pond,and tidal flat.China’s coastal aquaculture shows a dramatic potential range from−5401.28×10^(4)t to 84.65×10^(4)t,acting as both a carbon sink and a source.Floating raft(11.19×10^(4)t to 105.65×10^(4)t)and tidal flat(42.83×10^(4)t to 114.35×10^(4)t)are net carbon sinks.In contrast,net cage(−427.39×10^(4)t to−4.26×10^(4)t)and pond(−5027.91×10^(4)t to−131.09×10^(4)t)are significant net carbon sources.This heterogeneity is driven by differences in species,feed inputs,energy consumption,and management practices.The results highlight the need for targeted low-carbon technologies in high-emission systems to maximize carbon sequestration and mitigate their environmental impacts.This study provides a scientific basis for optimizing carbon management and offers insights for global sustainable aquaculture and carbon neutrality.展开更多
Enzyme-Induced Carbonate Precipitation(EICP)is an innovative technique to improve soil strength and reduce permeability.However,the use of EICP for reinforcing underwater sand beds remains largely unexplored.To advanc...Enzyme-Induced Carbonate Precipitation(EICP)is an innovative technique to improve soil strength and reduce permeability.However,the use of EICP for reinforcing underwater sand beds remains largely unexplored.To advance EICP implementation in various geotechnical applications,this paper develops a model box system to investigate the effectiveness of the EICP technique in reinforcing underwater sand beds.An"injection-extraction"system is designed to facilitate the flow of the EICP solution through underwater sand layers.Key parameters,including conductivity,pH,and Ca^(2+)concentration of the solution,are measured and analyzed.Electrical resistivity tomography(ERT)is utilized to evaluate the reinforcement effect in the underwater sand bed.The permeability of the model is tested to verify the feasibility of EICP technology for strengthening underwater sands.Furthermore,scanning electron microscope(SEM)is performed to investigate the growth mechanisms of calcium carbonate(CaCO_(3))crystals.The results show that the permeability of the model decreases from 1.28×10^(-2)m/s to 9.66×10^(-5)m/s,representing a reduction of approximately three orders of magnitude.This verifies that the EICP technology can greatly reduce the permeability of underwater sand beds.With increasing grouting cycles,the resistivity of the underwater sand initially decreases and then increases.This variation in sand resistivity is significantly influenced by the ion concentration in the solution,resulting in marked differences in resistivity at various depths and positions within the sand.The findings from this study offer a theoretical basis for the application of EICP technology in reinforcing seabed foundations and supporting marine infrastructure such as offshore pipelines,wind turbines,and oil platforms.展开更多
Frequent droughts pose considerable threat to global forest carbon uptake,but little is known about the response of forest carbon fluxes in climatic transition zones to seasonal drought.In this study,the responses of ...Frequent droughts pose considerable threat to global forest carbon uptake,but little is known about the response of forest carbon fluxes in climatic transition zones to seasonal drought.In this study,the responses of carbon fluxes to seasonal drought in two natural forests(Quercus aliena var.acute serrata Maxim and Pinus tabuliformis Carr.)in the Baotianman Nature Reserve were investigated.The Q.aliena forest exhibited a high resilience with stable gross primary productivity(GPP).However,ecosystem respiration(Re)significantly declined by 18.4%compared with normal years,leading to an increase in net carbon sequestration capacity of 4.1%.This resilience was attributed to its deep root system accessing soil water(SWC_(50cm))to sustain stomatal openness,coupled with the efficient utilization of photosynthetically active radiation to drive photosynthesis.In contrast,the P.tabuliformis forest,which relied on shallow soil moisture(SWC_(20cm)),experienced simultaneous decreases in both GPP and Re during drought,with a sharply greater decrease in GPP,resulting in low net carbon sink capacity.Further analysis revealed that the Q.aliena forest prioritized carbon assimilation through a deep water-stomatal synergy strategy(anisohydric behavior),whereas the P.tabuliformis forest adopted an isohydric strategy favoring water conservation at the expense of carbon fixation efficiency.These findings highlight distinct mechanisms underlying drought adaptation between forest types,providing critical insight into optimizing forest carbon cycle models and selecting drought-resistant species under the influence of climate change.展开更多
Acute carbon monoxide(CO) poisoning constitutes a lethal hazard globally,causing substantial mortality and morbidity worldwide.^([1-2]) Studies have shown that multiple mechanisms contribute to acute CO poisoning,incl...Acute carbon monoxide(CO) poisoning constitutes a lethal hazard globally,causing substantial mortality and morbidity worldwide.^([1-2]) Studies have shown that multiple mechanisms contribute to acute CO poisoning,including ischemic-hypoxic injury,reactive oxygen species(ROS) generation and inflammatory responses.^([2-5]) Furthermore,excessive inflammatory responses can induce adverse metabolic changes.^([6-7]) Considering these evidence,an interaction may exist between acute CO poisoning and both inflammatory factors and metabolites.However,the mechanisms through which inflammatory factors mediate CO toxicity via metabolic pathways remain largely unexplored.展开更多
To improve the performance of low-carbon magnesia carbon refractories,specimens were prepared using fused magnesia with particle sizes of 3-1,≤1,and≤0.074 mm,flake graphite with a particle size of≤0.15 mm as the ma...To improve the performance of low-carbon magnesia carbon refractories,specimens were prepared using fused magnesia with particle sizes of 3-1,≤1,and≤0.074 mm,flake graphite with a particle size of≤0.15 mm as the main raw materials,phenolic resin as the binder,and adding alumina micropowder with mass percentages of 1%,3%,5%,7%,and 9%,respectively.The obtained green specimens were then cured at 200℃for 24 h and heat-treated at 950℃or 1550℃for 3 h.The effects of the alumina micropowder addition on the properties(including the apparent porosity,bulk density,cold compressive strength,cold modulus of rupture,hot modulus of rupture,and thermal shock resistance)as well as on the phase composition and microstructure of the low-carbon magnesia carbon specimens were investigated.The results show that the physical properties of the specimens are improved as the alumina micropowder addition increases,mainly due to the in-situ reaction between magnesia and alumina to form spinel,which enhances the bonding of the matrix and thus strengthens the overall bonding of the specimens.After the heat treatment at 1550℃,the bulk density,cold compressive strength,and cold modulus of rupture of the specimens first increase and then decrease with the increase of the alumina micropowder addition,reaching the optimal values when the addition is 7%.Both the linear change rate and volume change rate of the specimens increase with the increasing alumina micropowder addition.展开更多
Hard carbon(HC)in sodium-ion batteries is searched by numerous investigations,which can offer the excellent performance of reversible Na^(+)insertion and extraction.The covalent heteroatom doping in HC is recently wor...Hard carbon(HC)in sodium-ion batteries is searched by numerous investigations,which can offer the excellent performance of reversible Na^(+)insertion and extraction.The covalent heteroatom doping in HC is recently worth concentrating,which can dilate the interlayer spacing of graphite to adjust the electrochemical storage performance in carbon anodes.However,the reported doping strategies of the modified HC have only resulted in limited improvement,especially unobvious effects on tuning porous structure.In this study,tannin extract and K_(2)SO_(4) are respectively utilized as carbon source and sulfur source for the fabrication of HC,in which K_(2)SO_(4) can contribute to the heteroatom doping,and the pore forming as well.The tannin-derived sulfur-doped carbon anode shows the excellent cycle stability,achieving a high reversible capacity of 520.5 mAh/g at a current density of 100 mA/g.Even after 500 cycles at a current density of 3 A/g,a high specific capacity of 236.7 mAh/g and a capacity retention rate of 92.6%can be reserved.Compared with the initial carbon,the adsorption energy of Na^(+)is multifold times higher,whereas Na^(+)diffusion energy barriers manyfold decrease.Moreover,the full battery assembled with Na_(3)V_(2)(PO_(4))_(3)/tannin-based HC demonstrates a stable cycling performance.This work can manifest the potentiality of the tannin-based electrode as anode for a high-performance sodium-ion batteries(SIBs),which could especially offer an explanation of Na^(+)storage and solid-electrolyte interface(SEI)stability to the electrochemical performance.展开更多
Developing on-demand biomass valorization represents an ideal path to alleviate the double burden of a sustainable energy-environment future,yet exploring tunable lignin-first chemistry to accomplish multifunctional w...Developing on-demand biomass valorization represents an ideal path to alleviate the double burden of a sustainable energy-environment future,yet exploring tunable lignin-first chemistry to accomplish multifunctional water purification remains elusive.Herein,we report a versatile solvent-fractionation to construct heteroatom-doped multicolor lignin carbon quantum dots(CQDs)with the functions of bimodal pollutant sensing,metal-ionic visualization,and photocatalytic antibiotic dissociation.With the aid of oxidation cleavage and biphasic extraction,the underlying lignin features of molecular weight and functional linkages influence the quantum size and core-surface state of CQDs conferring the unique optical-structure-performance.The N,S co-doped blue-emitting CQDs via light-quenching offer the selective identification of Fe^(3+)-ions in a broad response range with an acceptable limit of detection.The addition of L-cysteine can efficiently restore the fluorescence of CQDs by forming a stable Fe^(3+)-L-cys complex.The green-emissive CQDs are facilely embedded into cellulose hydrogel to directly visualize the presence of metal-ions.A red-CQDs modified ternary ZnIn2S4(ZIS)composite is fabricated to achieve photocatalytic antibiotic removal with an efficiency of~85%.The excellent photo-generated electron and storage capabilities of CQDs improve the light-capturing,electron conduction,and charge carrier separation of ZIS.The reactive species are of importance to photocatalytic tetracycline oxidation,wherein the electron holes(h+)function as the main contributor followed by∙O_(2)^(-),1O2 and∙OH.The directly interfacial electron escaping-shuttling with the help of optimized electronic and energy-band structures is confirmed via electrochemical test and theoretical computation.We anticipate that the present work not only sheds substantial light to manipulate polychromatic lignin-based CQDs via a tailored solvent-engineering,but also presents an emerging green route of emphasizing biomass-water nexus.展开更多
The principal challenge in optimizing biomass-derived hard carbon(HC)is the concurrent enhancement of specific capacity,cycling durability,and rate performance,as these properties are closely related to the disordered...The principal challenge in optimizing biomass-derived hard carbon(HC)is the concurrent enhancement of specific capacity,cycling durability,and rate performance,as these properties are closely related to the disordered carbon network and abundant pore structure.However,inadequate controllability of morphology,insufficiently regulated pore structures,and the complexity of post-processing modifications hinders the practical application of HC.In this work,a high-temperature and high-pressure expansion pretreatment technique is proposed to regulate the structure of starch precursors,enabling the precise design of ordered graphitic-like microcrystals and closed pores within HC.The optimized starch-based HC displayed remarkable electrochemical efficiency,with a reversible capacity of 332.0 mAh g^(-1),an initial Coulombic efficiency of 90.4%,and stable cycling over 3000 cycles.Meanwhile,advanced full-cell utilizing Na4Fe3(PO_(4))_(2)P_(2)O_(7) cathode achieve stable cycling performance exceeding 1000 cycles,demonstrating outstanding performance.This research innovatively employs a green expansion process to achieve structural regulation of HC,thereby providing an environmentally friendly and economically viable technical pathway for its large-scale production.展开更多
Metal-organic framework(MOF)-derived porous carbon has attracted particular attention in the electrochemical energy storage field,of which the key is the design and preparation of electrode materials with adjustable p...Metal-organic framework(MOF)-derived porous carbon has attracted particular attention in the electrochemical energy storage field,of which the key is the design and preparation of electrode materials with adjustable porosity and defects for supercapacitors.Here,a novel strategy of coating ZIF-8 with coal tar pitch(CTP)is presented to tailor the porosity and defects of derived porous carbon,by which the inward contraction of ZIF-8 is prevented to enlarge the ultra-micropores,and the defects of ZIF-8-derived carbon are repaired to form a continuous conjugated network.The tradeoff between porosity and electrical conductivity endows this novel hard/soft carbon electrode with fast ion/electron diffusion,achieving high yet balanced capacitance and rate performance of a top-level specific area-normalized capacitance(40μF cm^(-2))and a capacitance retention of 52.1%at a 1000-fold increased current density.Meanwhile,the novel electrode realizes a high capacitance of 704 F g^(-1)at 1 A g^(-1)and capacitance retention of 91.9%after 50000 cycles in KOH+PPD electrolyte.This study provides an effective approach to designing novel hard/soft carbon with tuned porosity and carbon defects from MOFs and CTP for supercapacitors and other metal-ion batteries.展开更多
基金supported by the University of Seoul’s 2025 Research Fund.
文摘Vanadium redox flow batteries(VRFBs)are a means of large-scale energy storage due to their excellent scalability,safety,long cycling life,and decoupled power and energy capacities.However,the slow redox kinetics of vanadium species on conventional carbon electrodes remains a major limitation to their performance.We investigated the deposition of carbon black,carbon nanotubes,and electrochemically exfoliated graphene(Exf-Gr)onto thermally-activated carbon paper(ACP)by spray coating to increase the electrode electrocatalytic activity.The modified electrodes were characterized using scanning electron microscopy,X-ray diffraction,Raman spectroscopy,X-ray photoelectron microscopy,and surface area analysis,while their electrochemical properties were evaluated by cyclic voltammetry,electrochemical impedance spectroscopy,and singlecell VRFB testing.Among the modified electrodes,Exf-Gr/ACP had the best performance,achieving a 2.9-fold reduction in charge transfer resistance compared to pristine ACP and delivering 2.5 times the discharge capacity in single-cell tests.This improvement is attributed to Exf-Gr’s high surface area,favorable catalytic activity,and excellent dispersion on the ACP substrate.Surface modification with electrochemically exfoliated graphene is a highly effective strategy for improving the electrode performance in VRFB systems,with significant implications for large-scale energy storage.
基金financially supported by the National Natural Science Foundation of China(Nos.22272118,22172111,and 22309134)the Science and Technology Commission of Shanghai Municipality,China(Nos.22ZR1464100,20ZR1460300,and 19DZ2271500)+2 种基金the China Postdoctoral Science Foundation(2022M712402),the Shanghai Rising-Star Program(23YF1449200)the Zhejiang Provincial Science and Technology Project(2022C01182)the Fundamental Research Funds for the Central Universities(2023-3-YB-07)。
文摘Carbon superstructures with multiscale hierarchies and functional attributes represent an appealing cathode candidate for zinc hybrid capacitors,but their tailor-made design to optimize the capacitive activity remains a confusing topic.Here we develop a hydrogen-bond-oriented interfacial super-assembly strategy to custom-tailor nanosheet-intertwined spherical carbon superstructures(SCSs)for Zn-ion storage with double-high capacitive activity and durability.Tetrachlorobenzoquinone(H-bond acceptor)and dimethylbenzidine(H-bond donator)can interact to form organic nanosheet modules,which are sequentially assembled,orientally compacted and densified into well-orchestrated superstructures through multiple H-bonds(N-H···O).Featured with rich surface-active heterodiatomic motifs,more exposed nanoporous channels,and successive charge migration paths,SCSs cathode promises high accessibility of built-in zincophilic sites and rapid ion diffusion with low energy barriers(3.3Ωs-0.5).Consequently,the assembled Zn||SCSs capacitor harvests all-round improvement in Zn-ion storage metrics,including high energy density(166 Wh kg-1),high-rate performance(172 m Ah g^(-1)at 20 A g^(-1)),and long-lasting cycling lifespan(95.5%capacity retention after 500,000 cycles).An opposite chargecarrier storage mechanism is rationalized for SCSs cathode to maximize spatial capacitive charge storage,involving high-kinetics physical Zn^(2+)/CF_(3)SO_(3)-adsorption and chemical Zn^(2+)redox with carbonyl/pyridine groups.This work gives insights into H-bond-guided interfacial superassembly design of superstructural carbons toward advanced energy storage.
文摘Carbon-based materials have gained significant attention in anticancer treatment because of their exceptional biocompatibility,yet critical challenges persist in establishing definitive correlations between their porous structures and functional performance.We report the use of a silica template to guide pore formation in the design of mesoporous carbon spheres(mC)with tailored pore structures for improved combined photothermal-chemotherapy.The mesopore size of mC has been adjusted by kinetic control of the resin polymerization and silica hydrolysis.Structural characterization showed that 4.4 nm mesopores enabled an exceptional gemcitabine loading of 228 mg g^(−1) and a sustained pH/thermal dual-responsive release with>70%drug release under near-infrared(NIR)irradiation.Finite element analysis demonstrated pore size-dependent heat transfer dynamics,with the improved mC achieving a superior photothermal conversion efficiency of 62%by a combination of N-doping and defect engineering.In vitro evaluations confirmed outstanding biocompatibility with>95%cell viability at 200μg mL^(−1) and potent tumor suppression in pancreatic and biliary cancer models with an~5%cell viability at 25μg mL^(−1) where combined therapy showed a 3.7-fold increased cytotoxicity over monotherapy.The improved structure of mC facilitated cascade therapeutic effects with enhanced tumor permeability derived from NIR-triggered hyperthermia and prolonged therapeutic exposure due to pH-responsive drug release.This pore engineering strategy establishes a structure-function process for next-generation theranostic platforms,addressing the critical limitations of conventional pancreatic and biliary cancer therapies through spatiotemporal control of multimodal treatment.
基金Supported by National Key R&D Program of China(2025YFE0109700)the National Natural Science Foundation of China(52106150)。
文摘CO_(2) capture and utilization(CCU)technologies have been recognized as crucial strategies for mitigating global warming,reducing carbon emission,and promoting resource circularity.As such,the design and development of related materials have attracted considerable research attention.Carbon-based materials,characterized by tunable pore structures,abundant active sites,high specific surface area,and excellent chemical stability,demonstrate significant potential for applications in CO_(2) capture and utilization.This review systematically analyzes the adsorption behaviors and performance variations of typical carbon materials,including activated carbon,porous carbon,graphene,and carbon nanotubes during CO_(2) capture processes.Concerning CO_(2) utilization,emphasis is placed on recent advances in the catalytic applications of carbon-based materials in key reactions such as methanation,reverse water-gas shift,dry reforming of methane,and alcohol synthesis.Moreover,the benefits and drawbacks of carbon materials in terms of CO_(2) adsorption capacity,catalytic activity,and stability are thoroughly evaluated,and their potential applications in integrated CO_(2) capture and utilization technologies are discussed.Finally,key strategies for enhancing the performance of carbonaceous materials through structural modulation and surface modification are elucidated.This review aims to provide theoretical guidance for the future development and large-scale implementation of carbon-based materials in CCU technologies.
基金financial support provided by Kuwait Institute for Scientific Research(KISR).
文摘Nanoporous carbon materials were synthesized from asphaltenes using a thermo-chemical treatment under an inert atmosphere and in-situ KOH activation.N-doping was also employed in certain samples to reveal the impact of nitrogen on the properties of materials.The synthesized materials were fully characterized to disclose their textural properties,structural parameters,surface functional groups,elemental compositions,and morphologies.Textural property analysis revealed a remarkable increase in surface areas after alkaline treatment(~1500-2000 m^(2)/g),which was mainly ascribed to the formation of micro-and mesopores.The measurements of structural parameters endorse and complement the findings on textural properties.The asphaltene-derived porous carbons have been employed in energy storage and carbon capture applications.The materials exhibit specific capacitances ranging from 130 to 180 F/g at 0.2 A/g in a 3 M KOH.These results suggest that nitrogen doping significantly enhances the pseudocapacitive behavior of the electroactive materials by promoting Fara-daic redox reactions and improving ion diffusion and adsorption rates.Asphaltene-derived porous carbons also exhibit notable CO_(2)adsorption capacities of 3-4 mmol/g at 25◦C and 1 bar.Also,breakthrough experiments confirm that the N-doped material exhibits remarkable stability,reusability,and increased surface basicity,achieving an impressive CO_(2)uptake of 0.446 mmol/g.These results highlight the potential of asphaltene-based porous carbons as efficient materials for carbon capture and energy storage applications.
文摘Despite their high theoretical capacity and energy density,lithiumsulfur(Li–S)batteries still face challenges such as soluble lithium polysulfides(LiPSs)shuttling and sluggish redox kinetics.In this work,we used a novel MoS_(2)-Mo_(2)C heterostructure anchored on a carbon sponge(CS)as a Li_(2)S host to solve these problems.A simple hydrothermal process following carbothermal reduction was used to construct the MoS_(2)-Mo_(2)C heterostructure,enabling control of the phases and integration of MoS_(2) and Mo_(2)C.Structural characterization confirmed the coherent interface of the heterostructure with a precise orientation relationship between the two phases and their uniform distribution.An evaluation of the adsorption and catalytic performance of the material showed that it has an exceptional LiPSs adsorption capacity with faster conversion from Li_(2)S_(4) to Li_(2)S_(2).Density functional theory calculations further confirmed these results.As a result,the cathode had a high initial discharge capacity of 693 mAh g^(−1) at 0.2 C and achieved stable cycling at 2 C for 500 cycles with a low decay rate of 0.107%per cycle.The heterostructure design,coupled with the macroporous CS framework,effectively prevented the shuttling and increased sulfur utilization,offering a promising way to produce practical high-energydensity Li–S batteries.
基金funded by the National Key Research and Development Program of China(2016yfd30300508,2017YFD0301602,and 2018yfd0301105)the Science&Technology Development Fund of Fujian Agriculture and Forestry University,China(kf2015043)。
文摘The rice ratooning system has attracted increasing attention in southern China due to its low carbon emissions and high yield potential.However,the net carbon budget and underlying mechanisms remain unclear.Three rice cropping systems were established in this trial experiment conducted from 2021 to 2022 in Fuzhou(25°05'N,119°13'E),Southeast China:ratooning rice(RR:MC+RSR)pattern for rice ratooning,single-cropping rice(LR_(1)),and double-cropping rice(DC:ER+LR_(2)).The closed static dark box gas collection,dry matter determination,life cycle assessment(LCA)etc.approaches were utilized to investigate the mechanism of“high carbon fixation–low emissions”mechanism in RR.A comprehensive assessment was conducted across multiple dimensions,including crop yield,greenhouse gas(GHG)emissions,carbon and nitrogen footprints,resource use efficiency,carbon sequestration capacity,and carbon budget balance.Results showed that the average daily yield of ratoon season rice(RSR)across RR treatments from 2021 to 2022 was 28.21–47.40%higher than that of the main crop(MC)and LR_(1),and the average daily yield of RR was 13.50–27.76%higher than DC.This yield advantage was attributed to a 32.32–39.26%increase in the allocation of^(13)C-labeled photosynthetic products(including non-structural carbohydrates,NSCs)to panicle organs,and a 21.77–43.51%reduction in allocation to underground roots and soil.Furthermore,the average daily global warming potential(GWP)was 16.44 kg CO_(2)-eq ha^(–1)for RR,24.99 kg CO_(2)-eq ha^(–1)for LR_(1),and 21.32 kg CO_(2)-eq ha^(–1)for DC.Specifically,the average daily GWP of ratoon rice was 34.21%lower than that of LR_(1) and 22.90%lower than double-cropping rice.Similarly,the average daily greenhouse gas intensity(GHGI)of ratoon rice was 62.28%lower than LR_(1) and 28.96%lower than double-cropping rice.In terms of carbon and nitrogen footprints,the ratoon rice system exhibited average daily values of 34.54 kg CO_(2)-eq ha^(–1)and 0.47 kg N ha^(–1),respectively.In comparison,LR_(1) had values of 45.63 kg CO_(2)-eq ha^(–1)and 0.49 kg N ha^(–1),while double-cropping rice showed 43.38 kg CO_(2)-eq ha^(–1)and 0.53 kg N ha^(–1).These values represent reductions of 24.30%in carbon footprint and4.28%in nitrogen footprint relative to LR_(1),and 20.38 and 11.45%relative to double-cropping rice,respectively.Moreover,the average annual carbon budget surplus across systems was 22,380.01 kg CO_(2)-eq ha^(–1)for ratoon rice(MC+RSR),11,228.54 kg CO_(2)-eq ha^(–1)for LR_(1),and 23,772.15 kg CO_(2)-eq ha^(–1)for DC.Consequently,the resource utilization efficiency of the RR was 24.42 and 47.50%higher than that of single-cropping and double-cropping systems,respectively.Average daily economic returns also increased by 32.71 and 80.75%,respectively.These findings provide a robust theoretical foundation and practical guidance for advancing agricultural carbon neutrality technologies and ensuring food security.
基金Supported by the Science and Technology Cooperation and Exchange special project of Cooperation of Shanxi Province(202404041101014)the Fundamental Research Program of Shanxi Province(202403021212333)+3 种基金the Joint Funds of the National Natural Science Foundation of China(U24A20555)the Lvliang Key R&D of University-Local Cooperation(2023XDHZ10)the Initiation Fund for Doctoral Research of Taiyuan University of Science and Technology(20242026)the Outstanding Doctor Funding Award of Shanxi Province(20242080).
文摘To elucidate the effect of calcite-regulated activated carbon(AC)structure on low-temperature denitrification performance of SCR catalysts,this work prepared a series of Mn-Ce/De-AC-xCaCO_(3)(x is the calcite content in coal)catalysts were prepared by the incipient wetness impregnation method,followed by acid washing to remove calcium-containing minerals.Comprehensive characterization and low-temperature denitrification tests revealed that calcite-induced structural modulation of coal-derived AC significantly enhances catalytic activity.Specifically,NO conversion increased from 88.3%of Mn-Ce/De-AC to 91.7%of Mn-Ce/De-AC-1CaCO_(3)(210℃).The improved SCR denitrification activity results from the enhancement of physicochemical properties including higher Mn^(4+)content and Ce^(4+)/Ce^(3+)ratio,an abundance of chemisorbed oxygen and acidic sites,which could strengthen the SCR reaction pathways(richer NH_(3)activated species and bidentate nitrate active species).Therefore,NO removal is enhanced.
基金supported by the National Key R&D Program of China(No.2021YFB3501102).
文摘Porous carbon microspheres are widely regarded as a superior CO_(2) adsorbent due to their exceptional efficiency and affordability.However,better adsorption performance is very attractive for porous carbon microspheres.And modification of the pore structure is one of the effective strategies.In this study,multi-cavity mesoporous carbon microspheres were successfully synthesized by the synergistic method of soft and hard templates,during which a phenolic resin with superior thermal stability was employed as the carbon precursor and a mixture of silica sol and F108 as the mesoporous template.Carbon microspheres with multi-cavity mesoporous structures were prepared,and all the samples showed highly even mesopores,with diameters around 12 nm.The diameter of these microspheres decreased from 396.8 nm to about 182.5 nm with the increase of silica sol.After CO_(2) activation,these novel carbon microspheres(APCF0.5-S1.75)demonstrated high specific surface area(983.3 m^(2)/g)and remarkable CO_(2) uptake of 4.93 mmol/g at 0℃ and1 bar.This could be attributed to the unique multi-cavity structure,which offers uniform mesoporous pore channels,minimal CO_(2) transport of and a greater number of active sites for CO_(2) adsorption.
基金financially supported by the National Natural Science Foundation of China(No.22208129)2023 Jiangsu Province Large Scientific Instrument Open Sharing Autonomous Research Project(No.TC2023A033)。
文摘Photocatalysis is one of the most promising technologies for solving environmental and energy problems,but current photocatalysts still suffer from low visible light utilization and insufficient photogenerated charge separation efficiency.Therefore,in this work,D-A tubular materials with tubular carbon nitride(TCN)as electron donor(D)and 2-mercaptobenzothiazole(BZ)as electron acceptor(A)were constructed by molecular doping and modulation of the carbon nitride geometry.It was shown that the introduction of BZ could modulate the electronic structure of the catalyst,promote electron migration from TCN to BZ,and inhibit the recombination of photogenerated electrons and holes.Meanwhile,the ultra-thin tubular structure could expose more active sites.In addition,the adsorption of protons by BZ-TCN was further improved due to the modulation of the charge distribution between the components by the introduction of small molecules.Among them,the photocatalytic hydrogen production rate of BZ_(0.1)-TCN was twice that of TCN.The in-depth discussion of the components through theoretical calculations and characterization tests contributes to the understanding of the mechanism of photocatalytic hydrogen production.
基金supported by the Ministry of Trade,Industry,and Energy(MOTIE)[Grant number 20016789]the Korea Institute of Industrial Technology(UR-25-0008).
文摘This study investigated the efficient conversion of greenhouse gases(GHGs),CO_(2)and CH_(4)mixtures,into few-walled carbon nanotubes(FWCNTs)through an optimized single-step and dual-step chemical vapor deposition(CVD)process.In the single-step process for directly synthesizing FWCNTs from greenhouse gases,CO_(2)concentration,gas flowrates,and H_(2)addition were identified as factors influencing the growth of FWCNTs.It was demonstrated that minimizing the amounts of CO_(2)and H_(2)was essential for achieving complete CO_(2)conversion because CO_(2)acts as an oxidizing agent that hinders CNT growth,while an excess of H_(2)disrupts the chemical equilibrium of the CO_(2)conversion reaction,leading to side reactions that suppress FWCNTs formation.To overcome these limitations,a dual-step approach incorporating sequential catalytic reactions was developed.In the first step,the Ni/SiO_(2)catalyst was utilized to facilitate CO_(2)methanation,reducing CO_(2)amounts while generating CH_(4)-rich gas.In the second step,CH_(4)pyrolysis was performed over the FeMo/MgO catalyst,enabling the growth of high-quality FWCNTs.This sequential configuration successfully synthesized FWCNTs under conditions previously unattainable in the single-step process,validating the effectiveness of the dual-step design.The strategic optimization of process parameters and sequential catalytic reactions established a viable route for converting GHGs into valuable FWCNTs.
基金National Natural Science Foundation of China,No.42276231,No.41871112The Open Research Fund of the State Key Laboratory of Coastal and Marine Engineering,No.LP2518。
文摘Assessing the carbon sink potential of marine aquaculture is critical to fostering sustainable marine economic development and achieving carbon neutrality.This study evaluates the carbon sink potential of four nearshore aquaculture systems in China:floating raft,net cage,pond,and tidal flat.China’s coastal aquaculture shows a dramatic potential range from−5401.28×10^(4)t to 84.65×10^(4)t,acting as both a carbon sink and a source.Floating raft(11.19×10^(4)t to 105.65×10^(4)t)and tidal flat(42.83×10^(4)t to 114.35×10^(4)t)are net carbon sinks.In contrast,net cage(−427.39×10^(4)t to−4.26×10^(4)t)and pond(−5027.91×10^(4)t to−131.09×10^(4)t)are significant net carbon sources.This heterogeneity is driven by differences in species,feed inputs,energy consumption,and management practices.The results highlight the need for targeted low-carbon technologies in high-emission systems to maximize carbon sequestration and mitigate their environmental impacts.This study provides a scientific basis for optimizing carbon management and offers insights for global sustainable aquaculture and carbon neutrality.
基金supported by the National Youth Top-notch Talent Support Program of China(Grant No.00389335)the National Natural Science Foundation of China(Grant No.52378392)+1 种基金the“Foal Eagle Program”Youth Top-notch Talent Project of Fujian Province(Grant No.00387088)supports are gratefully acknowledged.
文摘Enzyme-Induced Carbonate Precipitation(EICP)is an innovative technique to improve soil strength and reduce permeability.However,the use of EICP for reinforcing underwater sand beds remains largely unexplored.To advance EICP implementation in various geotechnical applications,this paper develops a model box system to investigate the effectiveness of the EICP technique in reinforcing underwater sand beds.An"injection-extraction"system is designed to facilitate the flow of the EICP solution through underwater sand layers.Key parameters,including conductivity,pH,and Ca^(2+)concentration of the solution,are measured and analyzed.Electrical resistivity tomography(ERT)is utilized to evaluate the reinforcement effect in the underwater sand bed.The permeability of the model is tested to verify the feasibility of EICP technology for strengthening underwater sands.Furthermore,scanning electron microscope(SEM)is performed to investigate the growth mechanisms of calcium carbonate(CaCO_(3))crystals.The results show that the permeability of the model decreases from 1.28×10^(-2)m/s to 9.66×10^(-5)m/s,representing a reduction of approximately three orders of magnitude.This verifies that the EICP technology can greatly reduce the permeability of underwater sand beds.With increasing grouting cycles,the resistivity of the underwater sand initially decreases and then increases.This variation in sand resistivity is significantly influenced by the ion concentration in the solution,resulting in marked differences in resistivity at various depths and positions within the sand.The findings from this study offer a theoretical basis for the application of EICP technology in reinforcing seabed foundations and supporting marine infrastructure such as offshore pipelines,wind turbines,and oil platforms.
基金financially supported by the National Key Research and Development Program of China(2021YFD2200405)the National Natural Science Foundation of China(31930078)special funds for Baotianman Forest Ecosystem Research Station from Chinese Academy of Forestry and Ministry of Science and Technology of China。
文摘Frequent droughts pose considerable threat to global forest carbon uptake,but little is known about the response of forest carbon fluxes in climatic transition zones to seasonal drought.In this study,the responses of carbon fluxes to seasonal drought in two natural forests(Quercus aliena var.acute serrata Maxim and Pinus tabuliformis Carr.)in the Baotianman Nature Reserve were investigated.The Q.aliena forest exhibited a high resilience with stable gross primary productivity(GPP).However,ecosystem respiration(Re)significantly declined by 18.4%compared with normal years,leading to an increase in net carbon sequestration capacity of 4.1%.This resilience was attributed to its deep root system accessing soil water(SWC_(50cm))to sustain stomatal openness,coupled with the efficient utilization of photosynthetically active radiation to drive photosynthesis.In contrast,the P.tabuliformis forest,which relied on shallow soil moisture(SWC_(20cm)),experienced simultaneous decreases in both GPP and Re during drought,with a sharply greater decrease in GPP,resulting in low net carbon sink capacity.Further analysis revealed that the Q.aliena forest prioritized carbon assimilation through a deep water-stomatal synergy strategy(anisohydric behavior),whereas the P.tabuliformis forest adopted an isohydric strategy favoring water conservation at the expense of carbon fixation efficiency.These findings highlight distinct mechanisms underlying drought adaptation between forest types,providing critical insight into optimizing forest carbon cycle models and selecting drought-resistant species under the influence of climate change.
基金supported by the National Natural Science Foundation of China (82372211)。
文摘Acute carbon monoxide(CO) poisoning constitutes a lethal hazard globally,causing substantial mortality and morbidity worldwide.^([1-2]) Studies have shown that multiple mechanisms contribute to acute CO poisoning,including ischemic-hypoxic injury,reactive oxygen species(ROS) generation and inflammatory responses.^([2-5]) Furthermore,excessive inflammatory responses can induce adverse metabolic changes.^([6-7]) Considering these evidence,an interaction may exist between acute CO poisoning and both inflammatory factors and metabolites.However,the mechanisms through which inflammatory factors mediate CO toxicity via metabolic pathways remain largely unexplored.
基金National Natural Science Foundation of China(U24A20101)。
文摘To improve the performance of low-carbon magnesia carbon refractories,specimens were prepared using fused magnesia with particle sizes of 3-1,≤1,and≤0.074 mm,flake graphite with a particle size of≤0.15 mm as the main raw materials,phenolic resin as the binder,and adding alumina micropowder with mass percentages of 1%,3%,5%,7%,and 9%,respectively.The obtained green specimens were then cured at 200℃for 24 h and heat-treated at 950℃or 1550℃for 3 h.The effects of the alumina micropowder addition on the properties(including the apparent porosity,bulk density,cold compressive strength,cold modulus of rupture,hot modulus of rupture,and thermal shock resistance)as well as on the phase composition and microstructure of the low-carbon magnesia carbon specimens were investigated.The results show that the physical properties of the specimens are improved as the alumina micropowder addition increases,mainly due to the in-situ reaction between magnesia and alumina to form spinel,which enhances the bonding of the matrix and thus strengthens the overall bonding of the specimens.After the heat treatment at 1550℃,the bulk density,cold compressive strength,and cold modulus of rupture of the specimens first increase and then decrease with the increase of the alumina micropowder addition,reaching the optimal values when the addition is 7%.Both the linear change rate and volume change rate of the specimens increase with the increasing alumina micropowder addition.
基金supported by National Natural Science Foundation of China(Nos.32271791,32171709 and 22475053)Hunan Provincial Natural Science Foundation of China(No.2024JJ7643)Natural Science Foundation of Shanghai(No.22ZR1404100).
文摘Hard carbon(HC)in sodium-ion batteries is searched by numerous investigations,which can offer the excellent performance of reversible Na^(+)insertion and extraction.The covalent heteroatom doping in HC is recently worth concentrating,which can dilate the interlayer spacing of graphite to adjust the electrochemical storage performance in carbon anodes.However,the reported doping strategies of the modified HC have only resulted in limited improvement,especially unobvious effects on tuning porous structure.In this study,tannin extract and K_(2)SO_(4) are respectively utilized as carbon source and sulfur source for the fabrication of HC,in which K_(2)SO_(4) can contribute to the heteroatom doping,and the pore forming as well.The tannin-derived sulfur-doped carbon anode shows the excellent cycle stability,achieving a high reversible capacity of 520.5 mAh/g at a current density of 100 mA/g.Even after 500 cycles at a current density of 3 A/g,a high specific capacity of 236.7 mAh/g and a capacity retention rate of 92.6%can be reserved.Compared with the initial carbon,the adsorption energy of Na^(+)is multifold times higher,whereas Na^(+)diffusion energy barriers manyfold decrease.Moreover,the full battery assembled with Na_(3)V_(2)(PO_(4))_(3)/tannin-based HC demonstrates a stable cycling performance.This work can manifest the potentiality of the tannin-based electrode as anode for a high-performance sodium-ion batteries(SIBs),which could especially offer an explanation of Na^(+)storage and solid-electrolyte interface(SEI)stability to the electrochemical performance.
基金the National Natural Science Foundation of China(32171728 and 22008159)Wuhan Knowledge Innovation Project(2022020801020312).
文摘Developing on-demand biomass valorization represents an ideal path to alleviate the double burden of a sustainable energy-environment future,yet exploring tunable lignin-first chemistry to accomplish multifunctional water purification remains elusive.Herein,we report a versatile solvent-fractionation to construct heteroatom-doped multicolor lignin carbon quantum dots(CQDs)with the functions of bimodal pollutant sensing,metal-ionic visualization,and photocatalytic antibiotic dissociation.With the aid of oxidation cleavage and biphasic extraction,the underlying lignin features of molecular weight and functional linkages influence the quantum size and core-surface state of CQDs conferring the unique optical-structure-performance.The N,S co-doped blue-emitting CQDs via light-quenching offer the selective identification of Fe^(3+)-ions in a broad response range with an acceptable limit of detection.The addition of L-cysteine can efficiently restore the fluorescence of CQDs by forming a stable Fe^(3+)-L-cys complex.The green-emissive CQDs are facilely embedded into cellulose hydrogel to directly visualize the presence of metal-ions.A red-CQDs modified ternary ZnIn2S4(ZIS)composite is fabricated to achieve photocatalytic antibiotic removal with an efficiency of~85%.The excellent photo-generated electron and storage capabilities of CQDs improve the light-capturing,electron conduction,and charge carrier separation of ZIS.The reactive species are of importance to photocatalytic tetracycline oxidation,wherein the electron holes(h+)function as the main contributor followed by∙O_(2)^(-),1O2 and∙OH.The directly interfacial electron escaping-shuttling with the help of optimized electronic and energy-band structures is confirmed via electrochemical test and theoretical computation.We anticipate that the present work not only sheds substantial light to manipulate polychromatic lignin-based CQDs via a tailored solvent-engineering,but also presents an emerging green route of emphasizing biomass-water nexus.
基金supported by the National Natural Science Foundation of China(5257043994)the Natural Science Foundation of Yunnan Province(202501AS070125,202501CF070129)+1 种基金the Innovation Capacity Construction and Enhancement Projects of Engineering Research Center of Yunnan Province(2023-XMDJ-00617107)the Scientific and Technological Project of Yunnan Precious Metals Laboratory(YPML-20240502015).
文摘The principal challenge in optimizing biomass-derived hard carbon(HC)is the concurrent enhancement of specific capacity,cycling durability,and rate performance,as these properties are closely related to the disordered carbon network and abundant pore structure.However,inadequate controllability of morphology,insufficiently regulated pore structures,and the complexity of post-processing modifications hinders the practical application of HC.In this work,a high-temperature and high-pressure expansion pretreatment technique is proposed to regulate the structure of starch precursors,enabling the precise design of ordered graphitic-like microcrystals and closed pores within HC.The optimized starch-based HC displayed remarkable electrochemical efficiency,with a reversible capacity of 332.0 mAh g^(-1),an initial Coulombic efficiency of 90.4%,and stable cycling over 3000 cycles.Meanwhile,advanced full-cell utilizing Na4Fe3(PO_(4))_(2)P_(2)O_(7) cathode achieve stable cycling performance exceeding 1000 cycles,demonstrating outstanding performance.This research innovatively employs a green expansion process to achieve structural regulation of HC,thereby providing an environmentally friendly and economically viable technical pathway for its large-scale production.
基金funded by the National Natural Science Foundation of China (No. 52372037)the Natural Science Foundation of Anhui Province (Nos. 2408085MB032)+1 种基金the Outstanding Scientific Research and Innovation Team Program of Higher Education Institutions of Anhui Province (No. 2023AH010015)support from the Anhui International Research Center of Energy Materials Green Manufacturing and Biotechnology
文摘Metal-organic framework(MOF)-derived porous carbon has attracted particular attention in the electrochemical energy storage field,of which the key is the design and preparation of electrode materials with adjustable porosity and defects for supercapacitors.Here,a novel strategy of coating ZIF-8 with coal tar pitch(CTP)is presented to tailor the porosity and defects of derived porous carbon,by which the inward contraction of ZIF-8 is prevented to enlarge the ultra-micropores,and the defects of ZIF-8-derived carbon are repaired to form a continuous conjugated network.The tradeoff between porosity and electrical conductivity endows this novel hard/soft carbon electrode with fast ion/electron diffusion,achieving high yet balanced capacitance and rate performance of a top-level specific area-normalized capacitance(40μF cm^(-2))and a capacitance retention of 52.1%at a 1000-fold increased current density.Meanwhile,the novel electrode realizes a high capacitance of 704 F g^(-1)at 1 A g^(-1)and capacitance retention of 91.9%after 50000 cycles in KOH+PPD electrolyte.This study provides an effective approach to designing novel hard/soft carbon with tuned porosity and carbon defects from MOFs and CTP for supercapacitors and other metal-ion batteries.
