With the miniaturization and high-frequency evolution of antennas in 5G/6G communications,aerospace,and transportation,polymer composite papers integrating superior wave-transparent performance and thermal conductivit...With the miniaturization and high-frequency evolution of antennas in 5G/6G communications,aerospace,and transportation,polymer composite papers integrating superior wave-transparent performance and thermal conductivity for radar antenna systems are urgently needed.Herein,a down-top strategy was employed to synthesize poly(p-phenylene benzobisoxazole)precursor nanofibers(prePNF).The prePNF was then uniformly mixed with fluorinated graphene(FG)to fabricate FG/PNF composite papers through consecutively suction filtration,hot-pressing,and thermal annealing.The hydroxyl and amino groups in prePNF enhanced the stability of FG/prePNF dispersion,while the increasedπ-πinteractions between PNF and FG after annealing improved their compatibility.The preparation time and cost of PNF paper was significantly reduced when applying this strategy,which enabled its large-scale production.Furthermore,the prepared FG/PNF composite papers exhibited excellent wave-transparent performance and thermal conductivity.When the mass fraction of FG was 40 wt%,the FG/PNF composite paper prepared via the down-top strategy achieved the wave-transparent coefficient(|T|2)of 96.3%under 10 GHz,in-plane thermal conductivity(λ_(∥))of 7.13 W m^(−1)K^(−1),and through-plane thermal conductivity(λ_(⊥))of 0.67 W m^(−1)K^(−1),outperforming FG/PNF composite paper prepared by the top-down strategy(|T|2=95.9%,λ_(∥)=5.52 W m^(−1)K^(−1),λ_(⊥)=0.52 W m^(−1)K^(−1))and pure PNF paper(|T|2=94.7%,λ_(∥)=3.04 W m^(−1)K^(−1),λ_(⊥)=0.24 W m^(−1)K^(−1)).Meanwhile,FG/PNF composite paper(with 40 wt%FG)through the down-top strategy also demonstrated outstanding mechanical properties with tensile strength and toughness reaching 197.4 MPa and 11.6 MJ m^(−3),respectively.展开更多
Aramid papers (AP), made of aramid fibers, demonstrate superiority in electrical insulation applications. Unfortunately, the strength and electrical insulating properties of AP remain suboptimal, primarily due to the ...Aramid papers (AP), made of aramid fibers, demonstrate superiority in electrical insulation applications. Unfortunately, the strength and electrical insulating properties of AP remain suboptimal, primarily due to the smooth surface and chemical inertness of aramid fibers. Herein, AP are modified via the nacre-mimetic structure composed of aramid nanofibers (ANF) and carbonylated basalt nanosheets (CBSNs). This is achieved by impregnating AP into an ANF-CBSNs (A-C) suspension containing a 3D ANF framework as the matrix and 2D CBSNs as fillers. The resultant biomimetic composite papers (AP/A-C composite papers) exhibit a layered “brick-and-mortar” structure, demonstrating superior mechanical and electrical insulating properties. Notably, the tensile strength and breakdown strength of AP/A-C5 composite papers reach 39.69 MPa and 22.04 kV mm^(−1), respectively, representing a 155 % and 85 % increase compared to those of the control AP. These impressive properties are accompanied with excellent volume resistivity, exceptional dielectric properties, impressive folding endurance, outstanding heat insulation, and remarkable flame retardance. The nacre-inspired strategy offers an effective approach for producing highly promising electrical insulating papers for advanced electrical equipment.展开更多
Adsorption as an effective technique for the remediation of wastewater has been widely used in industrial wastewater treatment due to the advantage of cost-effectiveness,availability of the adsorbent and ease of opera...Adsorption as an effective technique for the remediation of wastewater has been widely used in industrial wastewater treatment due to the advantage of cost-effectiveness,availability of the adsorbent and ease of operation.However,the low adsorption capacity of the reported adsorbents is still a challenge for wastewater treatment with highefficiency.Here,we developed a super adsorbent(SUA-1),which was a kind of porous carbon nanofibers derived from a composite of PAN-based electrospinning and ZIF-8(PAN/ZIF-8)via simple heat treatment process.The asprepared SUA showed an ultra-high adsorption capacity for adsorbing methyl blue(MB)at nearly three times its own weight,as high as 2998.18 mg/g.A series tests demonstrated that the pore-making effect of ZIF-8 during heat treatment process endowed high BET surface area and generated ZnO components as chemical adsorption center.Under the synergistic effect of bonding and non-bonding forces including ionic bond,electrostatic interaction,andπ-πinteraction,the adsorption capacity has been greatly improved.In view of promising efficiency,this work provides guidance and insights for the preparation of highly efficient adsorbents based on electrospinning derived porous carbon nanofibers.展开更多
The extensive use of quinolones leads to serious residues in different water matrices and consequent ecological risks.Magnetic Co-Cu incorporated in-situ in carbon nanofibers(Co-Cu/CNFs)were prepared for peroxymonocar...The extensive use of quinolones leads to serious residues in different water matrices and consequent ecological risks.Magnetic Co-Cu incorporated in-situ in carbon nanofibers(Co-Cu/CNFs)were prepared for peroxymonocarbonate(PMC)activation during quinolone degradation.The as-synthesized nanocomposites exhibited a high aspect ratio,large specific surface area(283.6 m^(2)g^(-1)),encapsulated Co and Cu nanoparticles and magnetic response(6.2 emu g^(-1)).Complete pefloxacin degradation can be achieved in 8 min in the Co-Cu/CNFs activated PMC system,and six other commonly used and detected quinolones can also be completely removed in approximately half an hour.Furthermore,ciprofloxacin can be completely decomposed within 50 min in different actual water matrices.The remarkable catalytic activities of Co-Cu/CNFs might be attributed to the increasing conductivity and electron transfer capability according to electrochemical impedance spectroscopy.The Co-Cu/CNFs activated PMC system is superior to other counterpart activated peroxide systems in terms of faster removal rates,less leakage of metal ions and greater proportions of heterogeneous catalytic reactions.Singlet oxygen was the primary contributor to ciprofloxacin degradation,followed by hydroxyl,carbonate and superoxide anion radicals.The pharmacophores of 26ciprofloxacin transformation products were converted by reactive species,including 81%pharmacophore removal which is beneficial for subsequent natural attenuation or biological treatment.展开更多
Hemoglobin A1c(HbA1c),a key biomarker for long-term glucose regulation,is essential for diagnosing and managing diabetes mellitus.However,conventional HbA1c detection methods often suffer from limited sensitivity,narr...Hemoglobin A1c(HbA1c),a key biomarker for long-term glucose regulation,is essential for diagnosing and managing diabetes mellitus.However,conventional HbA1c detection methods often suffer from limited sensitivity,narrow detection ranges,slow response times,and poor long-term stability.In this study,we developed a high-performance amperometric biosensor for the selective detection of Fructosyl Valine(FV),a model compound for HbA1c,by immobilizing Fructosyl Amino Acid Oxidase(FAAO)onto a glassy carbon electrode modified with electrospun polyaniline/polyindole-Mn_(2)O_(3) nanofibers.Operating at an applied potential of 0.27 V versus Ag/AgCl,the biosensor achieved a rapid detection time of 2 s for FV concentrations up to 50µM,with a signal-to-noise ratio of 3.Under optimized conditions(pH 7.0 and 35℃),the biosensor exhibited a wide linear detection range from 0.1 to 3 mM and a high sensitivity of 38.42µA/mM.Importantly,the sensor retained approximately 70% of its initial activity after 193 days of storage at 4℃,demonstrating excellent long-term stability.These results suggest that the FAAO/polyaniline/polyindole-Mn_(2)O_(3) nanocomposite-based biosensor offers a promising platform for sensitive,rapid,and durable detection of HbA1c,providing significant potential for improving diabetes monitoring and management.展开更多
Alternative methods for biodiesel purification that focus on ease of operation,cost reduction,and elimination of contaminated residues or that are easier to treat have received more attention.The dry wash route was us...Alternative methods for biodiesel purification that focus on ease of operation,cost reduction,and elimination of contaminated residues or that are easier to treat have received more attention.The dry wash route was used as an alternative to the wet route in biodiesel production.Filter membranes were developed based on cellulose nanofibers as the matrix and sugarcane bagasse fibers or soy hulls,as reinforcement to the matrix,before and after two chemical treatments(carboxymethylation and regeneration with sulfuric acid).The filters were characterized by permeability capacity,morphology,wettability,porosity,SEM and mechanical properties.The filtered biodiesel was also completely characterized.One of the major impacts of dry purification of biodiesel was the glycerin content after filtration.The filters CNFBR 20-28,CNFSR 5-28,CNFSR 5-35,and CNFBC 5-28 produced purified biodiesel with glycerin content below 0.02%(200 mg/L).Another relevant fact is related to the best results for acidity index,combined alkalinity,and glycerin content,obtained by the regenerated filter CNFBR 20-28,which presented a considerable permeate flow rate value above 4145 L h^(-1) m^(-2),which can be related to compacted lamellar layers observed by SEM.The produced filters were applied to biodiesel purification using a low-pressure filtration system and a simple vacuum pump,which resulted in an appreciable reduction in cost.The produced filter with sugarcane bagasse fiber carboxymethylated at 28 mesh of granulometry was efficient for biodiesel purification,including the efficient removal of free glycerin,in agreement with the standards defined by the national controlling agencies.展开更多
Lithium-sulfur batteries are considered to be a new generation of high energy density batteries due to their non-toxicity,low cost and high theoretical specific capacity.However,the development of practical lithium-su...Lithium-sulfur batteries are considered to be a new generation of high energy density batteries due to their non-toxicity,low cost and high theoretical specific capacity.However,the development of practical lithium-sulfur batteries is seriously impeded by the sluggish multi-electron redox reaction of sulfur species and obstinate shuttle effect of polysulfides.In this study,a porous lanthanum oxychloride(LaOCl)nanofiber is designed as adsorbent and electrocatalyst of polysulfides to regulate the redox kinetics and suppress shuttling of sulfur species.Benefiting from the porous architecture and luxuriant active site of LaOCl nanofibers,the meliorative polarization effect and sulfur expansion can be accomplished.The LaOCl/S electrode exhibits an initial discharge specific capacity of 1112.3 mAh/g at 0.1 C and maintains a superior cycling performance with a slight decay of 0.02%per cycle over 1000 cycles at 1.0 C.Furthermore,even under a high sulfur loading of 4.6mg/cm^(2),the S cathode with LaOCl nanofibers still retains a high reversible areal capacity of 4.2 mAh/cm^(2)at 0.2 C and a stable cycling performance.Such a porous host expands the application of rare earth based catalysts in lithium-sulfur batteries and provides an alternative approach to facilitate the polysulfides conversion kinetics.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
Formaldehyde(HCHO),a significant indoor air pollutant,poses serious health risks to humans,making its removal a critical issue.Among the various methods for HCHO elimination,catalytic oxidation has emerged as one of t...Formaldehyde(HCHO),a significant indoor air pollutant,poses serious health risks to humans,making its removal a critical issue.Among the various methods for HCHO elimination,catalytic oxidation has emerged as one of the most efficient and practical approaches.In this study,hierarchical hollow nickel oxide nanofibers(NiO–HNF)are developed by using a semi-sacrificial template-assisted hydrothermal and calcination process.Platinum(Pt)nanoparticles are then loaded onto the NiO–HNF through an impregnation-chemical reduction process.The Pt/NiO–HNF nanocomposite demonstrates a marked improvement in HCHO decomposition activity at room temperature,which can be ascribed to its distinct structural features.The hierarchical structure of the nanocomposite,which provides a high specific surface area and abundant porosity,facilitates the uniform dispersion of Pt nanoparticles and increases the number of active sites available for catalysis.To further investigate the oxidation mechanism,in-situ diffuse reflectance infrared Fourier transform spectroscopy(in-situ DRIFTS)is utilized.The findings suggest that the main intermediates during the oxidation process are dioxymethylene and formate species.This study highlights the potential of hollow transition metal oxide composites as efficient materials for the removal of indoor air pollutants.展开更多
High-performance and low-cost anode materials are critical for superior sodium-ion batteries(SIBs).Herein,high-yield porous carbon nanofiber(CNF)anode materials(named CNFs@Cu–Ni)are prepared by chemical vapor deposit...High-performance and low-cost anode materials are critical for superior sodium-ion batteries(SIBs).Herein,high-yield porous carbon nanofiber(CNF)anode materials(named CNFs@Cu–Ni)are prepared by chemical vapor deposition using a specialized nanoporous Cu–Ni alloy catalyst.Density functional theory calculations indicate that Ni incorporation results in a shift of the d-band center of the catalyst from−2.34157 to−1.93682 eV.This phenomenon elucidates the remarkable adsorption capacity of the Cu–Ni catalyst toward C2H2,thereby facilitating the catalytic growth of high-performance CNFs.With this approach,a superior yield of 258.6%for deposited carbon is reached after growth for 1 h.The CNFs@Cu–Ni anode presents an outstanding discharge capacity of 193.6 mAh·g^(−1) at 1.0 A·g^(−1)over 1000 cycles and an exceptional rate capability by maintaining a capacity of 158.9 mAh·g^(−1)even at 5.0 A·g^(−1)in an ether-based electrolyte.It also exhibits excellent performance in the CNFs@Cu–Ni//NVP full battery attributed to the presence of abundant Na+adsorption sites on its surface.This study presents a new concept for the advancement of high-performance carbonaceous electrodes for SIBs.展开更多
Mesoporous framework supported metal nanoparticle catalyst represents a promising material platform for creating multiple active sites that drive tandem reactions. In this study, we demonstrate a novel catalyst design...Mesoporous framework supported metal nanoparticle catalyst represents a promising material platform for creating multiple active sites that drive tandem reactions. In this study, we demonstrate a novel catalyst design that involves the encapsulation of CuNi alloy nanoparticles within mesoporous silicon carbide nanofibers (mSiC_(f)) to achieve efficient tandem conversion of furfural (FFA) into 2-(isopropoxymethyl)furan (IPF). The unique one-dimensional (1D) mesoporous structure of mSiC_(f), coupled with abundant oxygen-containing groups, offers a favorable surface microenvironment for the stabilization of bimetallic CuNi active sites. Through carefully optimizing metal to acid sites, we have developed a catalyst containing a total mass ratio of 20 % Cu and Ni, which exhibits a remarkable performance with complete FFA conversion and 92 % IPF selectivity in 4 h. In-depth mechanistic investigations have revealed that the superior activity of this catalyst is attributed to a tandem reaction mechanism. Initially, FFA is hydrogenated at the dual metal active sites to produce furfuryl alcohol (FOL) as an intermediate, which is subsequently etherified at the acid sites with suitable species and strengths on the mSiC_(f) supports. Additionally, the robust 1D mSiC_(f) framework effectively protects the metal sites from agglomeration, resulting in excellent reusability of the catalyst. This study underscores the potential of mesoporous silicon carbide-supported bimetallic active sites for achieving enhanced tandem catalytic functionality.展开更多
Potassium-ion batteries(KIBs)are rising as a noteworthy contender to lithium-ion batteries(LIBs),particularly for large-scale applications,driven by the natural abundance and cost-effectiveness of potassium resource.Y...Potassium-ion batteries(KIBs)are rising as a noteworthy contender to lithium-ion batteries(LIBs),particularly for large-scale applications,driven by the natural abundance and cost-effectiveness of potassium resource.Yet,lacking anodes which can reversibly accommodate the larger K^(+)currently poses a critical development hurdle,highlighting an urgent need for innovative solutions.Herein,porous ZnO-SnO_(2)-graphene-carbon(ZTO-G-C)nanofibers are presented,featuring amorphous SnO_(2) and ZnO nanoparticles homogeneously dispersed within a carbon matrix,with the strategic graphene incorporation for enhanced performance.Employing an adjustable and straightforward electrospinning method,the nanofibers were crafted to achieve a stable fibrous architecture.When evaluated as KIB anodes,the ZTO-G-C nanofibers demonstrated remarkable cycling stability(retaining 230.82 mA·h/g over 100 cycles at 100 mA/g),and rate capability(184.78 mA·h/g at 1 A/g).This outstanding performance is due to the synergistic interaction among all active components,collectively enhancing the structural stability against volume expansion during K^(+)intercalation,facilitating efficient charge transport,and delivering exceptional cyclability,capacity,and rate performance.Moreover,the intrinsic pseudocapacitive behavior stemming from the porous carbon substrate of ZTO-G-C further boosts its overall K-storage capacity.It is anticipated that the insights gained from this study offer fresh perspectives for developing next-generation high-performance KIB anodes.展开更多
Aqueous zinc-ion batteries(AZIBs)have emerged as promising,practical energy storage devices based on their non-toxic nature,environmental friendliness,and high energy density.However,excellent rate characteristics and...Aqueous zinc-ion batteries(AZIBs)have emerged as promising,practical energy storage devices based on their non-toxic nature,environmental friendliness,and high energy density.However,excellent rate characteristics and stable long-term cycling performance are essential.These essential aspects create a need for superior cathode materials,which represents a substantial challenge.In this study,we used MXenes as a framework for NH_(4)V_(4)O_(10)(NVO)construction and developed electrodes that combined the high capacity of NVO with the excellent conductivity of MXene/carbon nanofibers(MCNFs).We explored the electrochemical characteristics of electrodes with varying NVO contents.Considering the distinctive layered structure of NVO,the outstanding conductivity of MCNFs,and the strong synergies between the two components.NVO-MCNFs exhibited better charge transfer compared with earlier materials,as well as more ion storage sites,excellent conductivity,and short ion diffusion pathways.A composite electrode with optimized NVO content exhibited an excellent specific capacitance of 360.6mAh g^(-1) at 0.5 A g^(-1) and an outstanding rate performance.In particular,even at a high current density of 10 A g^(-1),the 32NVO-MCNF exhibited impressive cycling stability:88.6%over 2500 cycles.The mechanism involved was discovered via comprehensive characterization.We expect that the fabricated nanofibers will be useful in energy storage and conversion systems.展开更多
Sodium-ion batteries(SIBs)show promising potential in the field of electrochemical energy storage due to their cost-effectiveness and similar operational mechanisms to lithium-ion batteries(LIBs).However,the dramatic ...Sodium-ion batteries(SIBs)show promising potential in the field of electrochemical energy storage due to their cost-effectiveness and similar operational mechanisms to lithium-ion batteries(LIBs).However,the dramatic volume expansion of electrode materials and the slow reaction kinetics caused by the large sodium ion(Na^(+))radius hinder the practical application of SIBs,Here,we successfully prepared SnS_(2-x)Se_(x)nanodots embedded within N-doped carbon nanofibers(CNF)for use as electrode materials of SIBs,The introduction Se provided abundant anionic defect sites for Na+storage and enlarged the interlayer spacing of SnS_(2).In addition,the ultraifne nanodot structure reduces the volume expansion of SnS_(2-x)Se_(x)and shortens the ion transport path.As an anode of SIBs,SnS_(2-x)Se_(x)/CNF demonstrates remarkable reversible capacity(719 mAh g^(-1)at 0.5 A g^(-1)),along with rapid charging ability(completing a charge in just 127 s).Meanwhile,the assembled full-cell battery manifested exceptional energy density of 165.8 Wh kg^(-1)at a high-power output of 5526 W kg^(-1).This study presents an effective strategy for fabricating highperformance sulphide-based anode materials for SIBs,offering broad prospects for application.展开更多
Based on the unique catalytic properties of precious metals,the introduction of precious metals into metal oxide semiconductors will greatly improve the gas-sensitive properties of materials.As a new type of porous ma...Based on the unique catalytic properties of precious metals,the introduction of precious metals into metal oxide semiconductors will greatly improve the gas-sensitive properties of materials.As a new type of porous material,metal–organic frameworks(MOF)can be used for gas separation and adsorption due to their adjustable pore size and acceptable thermal stability.In this work,the ZIF-71 MOF was synthesized on CuO nanofibers doped with different concentrations of Ru to form a Ru–CuO@ZIF-71 nanocomposite sensor,which was then used for H_(2)S detection.The sensor shows sensitivity to trace amounts of H_(2)S gas(100 ppb),and the response is greatly enhanced at the optimal Ru doping ratio and operating temperature.The introduction of the ZIF-71 membrane can significantly increase the selectivity of the sensor while further improving the sensitivity.Finally,the possible sensing mechanism of the Ru–CuO@ZIF-71 sensor was explored.The enhancement of the H_(2)S gas sensing properties may be attributed to the catalysis of Ru and the formation of the Schottky junction at the Ru–CuO interface.Besides,the calculation based on density functional theory reveals enhanced adsorption capacities of CuO for H_(2)S after Ru doping.Therefore,the Ru–CuO@ZIF-71 sensor has strong application potential in exhaled gas detection and portable detection of H_(2)S gas in industrial environments.展开更多
Carbon-based electromagnetic wave(EMW)absorbing materials attached with metal sulfides famous for good dielectric properties are favored by researchers,which can form heterogeneous interfaces and thus provide suppleme...Carbon-based electromagnetic wave(EMW)absorbing materials attached with metal sulfides famous for good dielectric properties are favored by researchers,which can form heterogeneous interfaces and thus provide supplementary loss mechanisms to make up for the deficiencies of a single material in energy attenuation.Here,Co_(9)S_(8)/Co@coral-like carbon nanofibers(CNFs)/porous carbon hybrids are successfully fabricated by hydrothermal and chemical vapor deposition.The samples have exceptional EMW absorb-ing properties,with a minimum reflection loss of-57.48 dB at a thickness of 2.94 mm and an effective absorption bandwidth of up to 6.10 GHz at only 2.20 mm.The interlocking structure formed by Co@coral-like CNFs,interfacial polarization generated by heterostructure of Co_(9)S_(8),abundant defects and large specific surface area resulted from porous properties are important factors in attaining magnetic-dielectric balance and excellent absorption performance.Different matrixes are selected instead of paraffin to investigate the effect of matrix materials on EMW absorbing capacity.Besides,the EMW attenuation potential for practical applications is also demonstrated by radar cross-section simulations,electric field intensity distribution and power loss density.This work provides a novel strategy for designing outstanding EMW absorbers with unique microstructures using facile and low-cost synthetic routes.展开更多
The Cu^(+)/Cu^(0)sites of copper-based catalysts are crucial for enhancing the production of multicarbon(C_(2+))products from electrochemical CO_(2)reduction reaction(eCO_(2)RR).However,the unstable Cu^(+)and insuffic...The Cu^(+)/Cu^(0)sites of copper-based catalysts are crucial for enhancing the production of multicarbon(C_(2+))products from electrochemical CO_(2)reduction reaction(eCO_(2)RR).However,the unstable Cu^(+)and insufficient Cu^(+)/Cu^(0)active sites lead to their limited selectivity and stability for C_(2+)production.Herein,we embedded copper oxide(CuO_(x))particles into porous nitrogen-doped carbon nanofibers(CuO_(x)@PCNF)by pyrolysis of the electrospun fiber film containing ZIF-8 and Cu_(2)O particles.The porous nitrogendoped carbon nanofibers protected and dispersed Cu^(+)species,and its micro porous structure enhanced the interaction between CuO_(x)and reactants during eCO_(2)RR.The obtained CuO_(x)@PCNF created more effective and stable Cu^(+)/Cu^(0)active sites.It showed a high Faradaic efficiency of 62.5%for C_(2+)products in Hcell,which was 2 times higher than that of bare CuO_(x)(~31.1%).Furthermore,it achieved a maximum Faradaic efficiency of 80.7%for C_(2+)products in flow cell.In situ characterization and density functional theory(DFT)calculation confirmed that the N-doped carbon layer protected Cu^(+)from electrochemical reduction and lowered the energy barrier for the dimerization of^(*)CO.Stable and exposed Cu^(+)/Cu^(0)active sites enhanced the enrichment of^(*)CO and promoted the C-C coupling reaction on the catalyst surface,which facilitated the formation of C_(2+)products.展开更多
Piezocatalytic hydrogen peroxide(H_(2)O_(2))generation is a promising synthesis method that has received increasing attention;however,the reaction pathway requires further investigation.Here,Bi_(5)Ti_(3)FeO_(15)nanofi...Piezocatalytic hydrogen peroxide(H_(2)O_(2))generation is a promising synthesis method that has received increasing attention;however,the reaction pathway requires further investigation.Here,Bi_(5)Ti_(3)FeO_(15)nanofibers are used to generate H_(2)O_(2)by harvesting mechanical energy,and the reaction pathways are investigated.The H_(2)O_(2)yield over Bi_(5)Ti_(3)FeO_(15)nanofibers steadily increases from 331μmol g1 h1 in the first cycle to 746μmol g1 h1 in the tenth cycle in pure water without a sacrificial agent.Reliable reaction pathways are revealed by monitoring the pH value changes in the reaction solution during the H_(2)O_(2)generation process.In the H_(2)O_(2)generation process,the water oxidation reaction(WOR)provides a large amount of H+in the reaction solution,which promotes the oxygen reduction reaction(ORR)for H_(2)O_(2)generation.Therefore,an efficient synergistic effect between ORR and WOR achieves dual-pathway H_(2)O_(2)generation,contributing to the excellent piezocatalytic performance of Bi_(5)Ti_(3)FeO_(15)nanofibers.Furthermore,mechanistic studies indicate that the piezocatalytic H_(2)O_(2)generation follows the energy band theory.This work not only demonstrates Bi_(5)Ti_(3)FeO_(15)nanofibers as efficient piezocatalysts for H_(2)O_(2)generation but also provides a simple and effective approach to elucidate reaction pathways.This approach can be applied in photocatalytic,tribocatalytic,and electrocatalytic H_(2)O_(2)generation.展开更多
Manganese-based chalcogenides have significant potential as anodes for sodium-ion batteries(SIBs) due to their high theoretical specific capacity, abundant natural reserves, and environmental friendliness. However, th...Manganese-based chalcogenides have significant potential as anodes for sodium-ion batteries(SIBs) due to their high theoretical specific capacity, abundant natural reserves, and environmental friendliness. However, their application is hindered by poor cycling stability, resulting from severe volume changes during cycling and slow reaction kinetics due to their complex crystal structure. Here, an efficient and straightforward strategy was employed to in-situ encapsulate single-phase porous nanocubic MnS_(0.5)Se_(0.5) into carbon nanofibers using electrospinning and the hard template method, thus forming a necklace-like porous MnS_(0.5)Se_(0.5)-carbon nanofiber composite(MnS_(0.5)Se_(0.5)@N-CNF). The introduction of Se significantly impacts both the composition and microstructure of MnS_(0.5)Se_(0.5), including lattice distortion that generates additional defects, optimization of chemical bonds, and a nano-spatially confined design. In situ/ex-situ characterization and density functional theory calculations verified that this MnS_(0.5)Se_(0.5)@N-CNF allevi- ates the volume expansion and facilitates the transfer of Na+/electron. As expected, MnS_(0.5)Se_(0.5)@N-CNF anode demonstrates excellent sodium storage performance, characterized by high initial Coulombic efficiency(90.8%), high-rate capability(370.5 m Ahg^(-1) at 10 Ag^(-1)) and long durability(over 5000 cycles at 5 Ag^(-1)). The MnS_(0.5)Se_(0.5)@N-CNF//NVP@C full cell, assembled with MnS_(0.5)Se_(0.5)@N-CNF as anode and Na_(3)V_(2)(PO_4)_(3)@C as cathode, exhibits a high energy density of 254 Wh kg^(-1) can be provided. This work presents a novel strategy to optimize the design of anode materials through structural engineering and Se substitution, while also elucidating the underlying reaction mechanisms.展开更多
The development of efficient,cost-effective catalysts for the oxygen reduction reaction(ORR)is crucial for advancing zinc-air batteries(ZABs).This study presents Fe_(4)N nanoparticles embedded in N-doped carbon nanofi...The development of efficient,cost-effective catalysts for the oxygen reduction reaction(ORR)is crucial for advancing zinc-air batteries(ZABs).This study presents Fe_(4)N nanoparticles embedded in N-doped carbon nanofibers(Fe_(4)N@CNF-NH_(3))as a highly efficient ORR catalyst.The Fe_(4)N@CNF-NH_(3)catalyst was synthesized via electrospinning,followed by high-temperature annealing in an NH_(3)atmosphere.This electrospinning technique ensured the uniform dispersion of Fe_(4)N nanoparticles within the carbon nanofibers(CNFs),preventing agglomeration and enhancing the availability of active sites.Structural and morphological analyses confirmed the formation of Fe_(4)N nanoparticles with a lattice spacing of 0.213 nm,surrounded by graphitic carbon structures that significantly improved the material’s conductivity and stability.Electrochemical tests demonstrated that Fe_(4)N@CNF-NH_(3)exhibited superior ORR activity,with a half-wave potential of 0.904 V,surpassing that of commercial Pt/C catalysts.This enhanced performance is attributed to the synergistic effects of Fe_(4)N nanoparticles and the conductive carbon framework,which facilitated efficient charge and mass transfer during the ORR process.Density functional theory calculations further revealed that the introduction of CNFs positively shifted the d-band center of Fe atoms,optimizing oxygen intermediate adsorption and lowering energy barriers for ORR.The practical applicability of Fe_(4)N@CNF-NH_(3)was validated through the assembly of both liquid-state and solid-state ZABs,which exhibited excellent cycling stability,high power density,and superior discharge voltage.This study offers a promising strategy for developing highly active,low-cost ORR catalysts and advances the potential for the commercialization of ZABs.展开更多
基金the support from the National Natural Science Foundation of China(52473083,52373089,52403085)Natural Science Basic Research Program of Shaanxi(2024JC-TBZC-04)+2 种基金the Innovation Capability Support Program of Shaanxi(2024RS-CXTD-57)Natural Science Basic Research Plan in Shaanxi Province of China(2024JC-YBMS-279)Natural Science Foundation of Chongqing,China(2023NSCQMSX2547)
文摘With the miniaturization and high-frequency evolution of antennas in 5G/6G communications,aerospace,and transportation,polymer composite papers integrating superior wave-transparent performance and thermal conductivity for radar antenna systems are urgently needed.Herein,a down-top strategy was employed to synthesize poly(p-phenylene benzobisoxazole)precursor nanofibers(prePNF).The prePNF was then uniformly mixed with fluorinated graphene(FG)to fabricate FG/PNF composite papers through consecutively suction filtration,hot-pressing,and thermal annealing.The hydroxyl and amino groups in prePNF enhanced the stability of FG/prePNF dispersion,while the increasedπ-πinteractions between PNF and FG after annealing improved their compatibility.The preparation time and cost of PNF paper was significantly reduced when applying this strategy,which enabled its large-scale production.Furthermore,the prepared FG/PNF composite papers exhibited excellent wave-transparent performance and thermal conductivity.When the mass fraction of FG was 40 wt%,the FG/PNF composite paper prepared via the down-top strategy achieved the wave-transparent coefficient(|T|2)of 96.3%under 10 GHz,in-plane thermal conductivity(λ_(∥))of 7.13 W m^(−1)K^(−1),and through-plane thermal conductivity(λ_(⊥))of 0.67 W m^(−1)K^(−1),outperforming FG/PNF composite paper prepared by the top-down strategy(|T|2=95.9%,λ_(∥)=5.52 W m^(−1)K^(−1),λ_(⊥)=0.52 W m^(−1)K^(−1))and pure PNF paper(|T|2=94.7%,λ_(∥)=3.04 W m^(−1)K^(−1),λ_(⊥)=0.24 W m^(−1)K^(−1)).Meanwhile,FG/PNF composite paper(with 40 wt%FG)through the down-top strategy also demonstrated outstanding mechanical properties with tensile strength and toughness reaching 197.4 MPa and 11.6 MJ m^(−3),respectively.
基金supported by the National Natural Science Foundation of China(No.22278260)the Open Foundation of Key Laboratory of Auxiliary Chemistry and Technology for Chemical Industry(No.KFKT2021-14)Shaanxi Collaborative Innovation Center of Industrial Auxiliary Chemistry and Technology(No.KFKT2021-14).
文摘Aramid papers (AP), made of aramid fibers, demonstrate superiority in electrical insulation applications. Unfortunately, the strength and electrical insulating properties of AP remain suboptimal, primarily due to the smooth surface and chemical inertness of aramid fibers. Herein, AP are modified via the nacre-mimetic structure composed of aramid nanofibers (ANF) and carbonylated basalt nanosheets (CBSNs). This is achieved by impregnating AP into an ANF-CBSNs (A-C) suspension containing a 3D ANF framework as the matrix and 2D CBSNs as fillers. The resultant biomimetic composite papers (AP/A-C composite papers) exhibit a layered “brick-and-mortar” structure, demonstrating superior mechanical and electrical insulating properties. Notably, the tensile strength and breakdown strength of AP/A-C5 composite papers reach 39.69 MPa and 22.04 kV mm^(−1), respectively, representing a 155 % and 85 % increase compared to those of the control AP. These impressive properties are accompanied with excellent volume resistivity, exceptional dielectric properties, impressive folding endurance, outstanding heat insulation, and remarkable flame retardance. The nacre-inspired strategy offers an effective approach for producing highly promising electrical insulating papers for advanced electrical equipment.
基金Natural Science Foundation of China(22134005,22204011)Chongqing Talents Program for Outstanding Scientists(cstc2021ycjh-bgzxm0179)。
文摘Adsorption as an effective technique for the remediation of wastewater has been widely used in industrial wastewater treatment due to the advantage of cost-effectiveness,availability of the adsorbent and ease of operation.However,the low adsorption capacity of the reported adsorbents is still a challenge for wastewater treatment with highefficiency.Here,we developed a super adsorbent(SUA-1),which was a kind of porous carbon nanofibers derived from a composite of PAN-based electrospinning and ZIF-8(PAN/ZIF-8)via simple heat treatment process.The asprepared SUA showed an ultra-high adsorption capacity for adsorbing methyl blue(MB)at nearly three times its own weight,as high as 2998.18 mg/g.A series tests demonstrated that the pore-making effect of ZIF-8 during heat treatment process endowed high BET surface area and generated ZnO components as chemical adsorption center.Under the synergistic effect of bonding and non-bonding forces including ionic bond,electrostatic interaction,andπ-πinteraction,the adsorption capacity has been greatly improved.In view of promising efficiency,this work provides guidance and insights for the preparation of highly efficient adsorbents based on electrospinning derived porous carbon nanofibers.
基金financially supported by the National Key R&D Program of China(Nos.2023YFC3708903,2021YFC3200101)the International Science&Technology Innovation Program of Chinese Academy of Agriculture Science(Nos.CAAS-CFSGLCA-IEDA-202302,CAAS-ZDRW202110)the People?s Republic of China and Republic of Korea Young Scientist Exchange Program
文摘The extensive use of quinolones leads to serious residues in different water matrices and consequent ecological risks.Magnetic Co-Cu incorporated in-situ in carbon nanofibers(Co-Cu/CNFs)were prepared for peroxymonocarbonate(PMC)activation during quinolone degradation.The as-synthesized nanocomposites exhibited a high aspect ratio,large specific surface area(283.6 m^(2)g^(-1)),encapsulated Co and Cu nanoparticles and magnetic response(6.2 emu g^(-1)).Complete pefloxacin degradation can be achieved in 8 min in the Co-Cu/CNFs activated PMC system,and six other commonly used and detected quinolones can also be completely removed in approximately half an hour.Furthermore,ciprofloxacin can be completely decomposed within 50 min in different actual water matrices.The remarkable catalytic activities of Co-Cu/CNFs might be attributed to the increasing conductivity and electron transfer capability according to electrochemical impedance spectroscopy.The Co-Cu/CNFs activated PMC system is superior to other counterpart activated peroxide systems in terms of faster removal rates,less leakage of metal ions and greater proportions of heterogeneous catalytic reactions.Singlet oxygen was the primary contributor to ciprofloxacin degradation,followed by hydroxyl,carbonate and superoxide anion radicals.The pharmacophores of 26ciprofloxacin transformation products were converted by reactive species,including 81%pharmacophore removal which is beneficial for subsequent natural attenuation or biological treatment.
文摘Hemoglobin A1c(HbA1c),a key biomarker for long-term glucose regulation,is essential for diagnosing and managing diabetes mellitus.However,conventional HbA1c detection methods often suffer from limited sensitivity,narrow detection ranges,slow response times,and poor long-term stability.In this study,we developed a high-performance amperometric biosensor for the selective detection of Fructosyl Valine(FV),a model compound for HbA1c,by immobilizing Fructosyl Amino Acid Oxidase(FAAO)onto a glassy carbon electrode modified with electrospun polyaniline/polyindole-Mn_(2)O_(3) nanofibers.Operating at an applied potential of 0.27 V versus Ag/AgCl,the biosensor achieved a rapid detection time of 2 s for FV concentrations up to 50µM,with a signal-to-noise ratio of 3.Under optimized conditions(pH 7.0 and 35℃),the biosensor exhibited a wide linear detection range from 0.1 to 3 mM and a high sensitivity of 38.42µA/mM.Importantly,the sensor retained approximately 70% of its initial activity after 193 days of storage at 4℃,demonstrating excellent long-term stability.These results suggest that the FAAO/polyaniline/polyindole-Mn_(2)O_(3) nanocomposite-based biosensor offers a promising platform for sensitive,rapid,and durable detection of HbA1c,providing significant potential for improving diabetes monitoring and management.
基金supported by the Minas Gerais State’s Foundation for Research Support(FAPEMIG,Brazil,Process CEX-APQ-01651-17,RED-00224-23,and PPM-00645-17).
文摘Alternative methods for biodiesel purification that focus on ease of operation,cost reduction,and elimination of contaminated residues or that are easier to treat have received more attention.The dry wash route was used as an alternative to the wet route in biodiesel production.Filter membranes were developed based on cellulose nanofibers as the matrix and sugarcane bagasse fibers or soy hulls,as reinforcement to the matrix,before and after two chemical treatments(carboxymethylation and regeneration with sulfuric acid).The filters were characterized by permeability capacity,morphology,wettability,porosity,SEM and mechanical properties.The filtered biodiesel was also completely characterized.One of the major impacts of dry purification of biodiesel was the glycerin content after filtration.The filters CNFBR 20-28,CNFSR 5-28,CNFSR 5-35,and CNFBC 5-28 produced purified biodiesel with glycerin content below 0.02%(200 mg/L).Another relevant fact is related to the best results for acidity index,combined alkalinity,and glycerin content,obtained by the regenerated filter CNFBR 20-28,which presented a considerable permeate flow rate value above 4145 L h^(-1) m^(-2),which can be related to compacted lamellar layers observed by SEM.The produced filters were applied to biodiesel purification using a low-pressure filtration system and a simple vacuum pump,which resulted in an appreciable reduction in cost.The produced filter with sugarcane bagasse fiber carboxymethylated at 28 mesh of granulometry was efficient for biodiesel purification,including the efficient removal of free glycerin,in agreement with the standards defined by the national controlling agencies.
基金supported by the Scientific Research Program Funded by Education Department of Shaanxi Provincial Government(No.22JK0411)the Natural Science Basic Research Program of Shaanxi Province(No.2023-JC-QN-0165)the National Natural Science Foundation of China(No.21603109).
文摘Lithium-sulfur batteries are considered to be a new generation of high energy density batteries due to their non-toxicity,low cost and high theoretical specific capacity.However,the development of practical lithium-sulfur batteries is seriously impeded by the sluggish multi-electron redox reaction of sulfur species and obstinate shuttle effect of polysulfides.In this study,a porous lanthanum oxychloride(LaOCl)nanofiber is designed as adsorbent and electrocatalyst of polysulfides to regulate the redox kinetics and suppress shuttling of sulfur species.Benefiting from the porous architecture and luxuriant active site of LaOCl nanofibers,the meliorative polarization effect and sulfur expansion can be accomplished.The LaOCl/S electrode exhibits an initial discharge specific capacity of 1112.3 mAh/g at 0.1 C and maintains a superior cycling performance with a slight decay of 0.02%per cycle over 1000 cycles at 1.0 C.Furthermore,even under a high sulfur loading of 4.6mg/cm^(2),the S cathode with LaOCl nanofibers still retains a high reversible areal capacity of 4.2 mAh/cm^(2)at 0.2 C and a stable cycling performance.Such a porous host expands the application of rare earth based catalysts in lithium-sulfur batteries and provides an alternative approach to facilitate the polysulfides conversion kinetics.
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 Guangxi Science and Technology Major Program(AA24263054)the National Natural Science Foundation of China(52472245 and 22278324).
文摘Formaldehyde(HCHO),a significant indoor air pollutant,poses serious health risks to humans,making its removal a critical issue.Among the various methods for HCHO elimination,catalytic oxidation has emerged as one of the most efficient and practical approaches.In this study,hierarchical hollow nickel oxide nanofibers(NiO–HNF)are developed by using a semi-sacrificial template-assisted hydrothermal and calcination process.Platinum(Pt)nanoparticles are then loaded onto the NiO–HNF through an impregnation-chemical reduction process.The Pt/NiO–HNF nanocomposite demonstrates a marked improvement in HCHO decomposition activity at room temperature,which can be ascribed to its distinct structural features.The hierarchical structure of the nanocomposite,which provides a high specific surface area and abundant porosity,facilitates the uniform dispersion of Pt nanoparticles and increases the number of active sites available for catalysis.To further investigate the oxidation mechanism,in-situ diffuse reflectance infrared Fourier transform spectroscopy(in-situ DRIFTS)is utilized.The findings suggest that the main intermediates during the oxidation process are dioxymethylene and formate species.This study highlights the potential of hollow transition metal oxide composites as efficient materials for the removal of indoor air pollutants.
基金financially supported by the National Natural Science Foundation of China(Nos.52271011 and 52102291)the Structure Design and Mass Preparation of High Stability and Low Cost PEM Hydroelectrolysis Non-Iridium Catalyst,China(No.KC22453)
文摘High-performance and low-cost anode materials are critical for superior sodium-ion batteries(SIBs).Herein,high-yield porous carbon nanofiber(CNF)anode materials(named CNFs@Cu–Ni)are prepared by chemical vapor deposition using a specialized nanoporous Cu–Ni alloy catalyst.Density functional theory calculations indicate that Ni incorporation results in a shift of the d-band center of the catalyst from−2.34157 to−1.93682 eV.This phenomenon elucidates the remarkable adsorption capacity of the Cu–Ni catalyst toward C2H2,thereby facilitating the catalytic growth of high-performance CNFs.With this approach,a superior yield of 258.6%for deposited carbon is reached after growth for 1 h.The CNFs@Cu–Ni anode presents an outstanding discharge capacity of 193.6 mAh·g^(−1) at 1.0 A·g^(−1)over 1000 cycles and an exceptional rate capability by maintaining a capacity of 158.9 mAh·g^(−1)even at 5.0 A·g^(−1)in an ether-based electrolyte.It also exhibits excellent performance in the CNFs@Cu–Ni//NVP full battery attributed to the presence of abundant Na+adsorption sites on its surface.This study presents a new concept for the advancement of high-performance carbonaceous electrodes for SIBs.
基金supported by the National Natu-ral Science Foundation of China(Nos.52225204,52173233,and 52202085)the Innovation Program of Shanghai Municipal Edu-cation Commission(No.2021-01-07-00-03-E00109)+4 种基金Natural Sci-ence Foundation of Shanghai(No.23ZR1479200)the Shanghai Sci-entific and Technological Innovation Project(No.24520712800)“Shuguang Program”Supported by the Shanghai Education Devel-opment Foundation and Shanghai Municipal Education Commis-sion(No.20SG33)the Fundamental Research Funds for the Central Universities(No.2232024Y-01)the DHU Distinguished Young Professor Program(Nos.LZA2022001and LZB2023002).
文摘Mesoporous framework supported metal nanoparticle catalyst represents a promising material platform for creating multiple active sites that drive tandem reactions. In this study, we demonstrate a novel catalyst design that involves the encapsulation of CuNi alloy nanoparticles within mesoporous silicon carbide nanofibers (mSiC_(f)) to achieve efficient tandem conversion of furfural (FFA) into 2-(isopropoxymethyl)furan (IPF). The unique one-dimensional (1D) mesoporous structure of mSiC_(f), coupled with abundant oxygen-containing groups, offers a favorable surface microenvironment for the stabilization of bimetallic CuNi active sites. Through carefully optimizing metal to acid sites, we have developed a catalyst containing a total mass ratio of 20 % Cu and Ni, which exhibits a remarkable performance with complete FFA conversion and 92 % IPF selectivity in 4 h. In-depth mechanistic investigations have revealed that the superior activity of this catalyst is attributed to a tandem reaction mechanism. Initially, FFA is hydrogenated at the dual metal active sites to produce furfuryl alcohol (FOL) as an intermediate, which is subsequently etherified at the acid sites with suitable species and strengths on the mSiC_(f) supports. Additionally, the robust 1D mSiC_(f) framework effectively protects the metal sites from agglomeration, resulting in excellent reusability of the catalyst. This study underscores the potential of mesoporous silicon carbide-supported bimetallic active sites for achieving enhanced tandem catalytic functionality.
基金Projects(51404103,51574117,62106074)supported by the National Natural Science Foundation of ChinaProject(2024JJ7135)supported by the Natural Science Foundation of Hunan Province,ChinaProject(24B0524)supported by the Scientific Research Foundation of Hunan Provincial Education Department,China。
文摘Potassium-ion batteries(KIBs)are rising as a noteworthy contender to lithium-ion batteries(LIBs),particularly for large-scale applications,driven by the natural abundance and cost-effectiveness of potassium resource.Yet,lacking anodes which can reversibly accommodate the larger K^(+)currently poses a critical development hurdle,highlighting an urgent need for innovative solutions.Herein,porous ZnO-SnO_(2)-graphene-carbon(ZTO-G-C)nanofibers are presented,featuring amorphous SnO_(2) and ZnO nanoparticles homogeneously dispersed within a carbon matrix,with the strategic graphene incorporation for enhanced performance.Employing an adjustable and straightforward electrospinning method,the nanofibers were crafted to achieve a stable fibrous architecture.When evaluated as KIB anodes,the ZTO-G-C nanofibers demonstrated remarkable cycling stability(retaining 230.82 mA·h/g over 100 cycles at 100 mA/g),and rate capability(184.78 mA·h/g at 1 A/g).This outstanding performance is due to the synergistic interaction among all active components,collectively enhancing the structural stability against volume expansion during K^(+)intercalation,facilitating efficient charge transport,and delivering exceptional cyclability,capacity,and rate performance.Moreover,the intrinsic pseudocapacitive behavior stemming from the porous carbon substrate of ZTO-G-C further boosts its overall K-storage capacity.It is anticipated that the insights gained from this study offer fresh perspectives for developing next-generation high-performance KIB anodes.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean Government(MSIT)(Nos.RS-2023-00217581 and RS-2023-00304768)the National Research Council of Science&Technology(NST)grant by the Korean Government(MSIT)(No.CAP 22073-000).
文摘Aqueous zinc-ion batteries(AZIBs)have emerged as promising,practical energy storage devices based on their non-toxic nature,environmental friendliness,and high energy density.However,excellent rate characteristics and stable long-term cycling performance are essential.These essential aspects create a need for superior cathode materials,which represents a substantial challenge.In this study,we used MXenes as a framework for NH_(4)V_(4)O_(10)(NVO)construction and developed electrodes that combined the high capacity of NVO with the excellent conductivity of MXene/carbon nanofibers(MCNFs).We explored the electrochemical characteristics of electrodes with varying NVO contents.Considering the distinctive layered structure of NVO,the outstanding conductivity of MCNFs,and the strong synergies between the two components.NVO-MCNFs exhibited better charge transfer compared with earlier materials,as well as more ion storage sites,excellent conductivity,and short ion diffusion pathways.A composite electrode with optimized NVO content exhibited an excellent specific capacitance of 360.6mAh g^(-1) at 0.5 A g^(-1) and an outstanding rate performance.In particular,even at a high current density of 10 A g^(-1),the 32NVO-MCNF exhibited impressive cycling stability:88.6%over 2500 cycles.The mechanism involved was discovered via comprehensive characterization.We expect that the fabricated nanofibers will be useful in energy storage and conversion systems.
基金financially supported by the National Natural Science Foundation of China(22278348)Natural Science Foundation of Xinjiang Autonomous Region(2022D01D05)+1 种基金National guidance for local projects of Xinjiang Autonomous Region(ZYYD2025JD09)Tianshan Leading technology talents Program of Xinjiang Autonomous Region。
文摘Sodium-ion batteries(SIBs)show promising potential in the field of electrochemical energy storage due to their cost-effectiveness and similar operational mechanisms to lithium-ion batteries(LIBs).However,the dramatic volume expansion of electrode materials and the slow reaction kinetics caused by the large sodium ion(Na^(+))radius hinder the practical application of SIBs,Here,we successfully prepared SnS_(2-x)Se_(x)nanodots embedded within N-doped carbon nanofibers(CNF)for use as electrode materials of SIBs,The introduction Se provided abundant anionic defect sites for Na+storage and enlarged the interlayer spacing of SnS_(2).In addition,the ultraifne nanodot structure reduces the volume expansion of SnS_(2-x)Se_(x)and shortens the ion transport path.As an anode of SIBs,SnS_(2-x)Se_(x)/CNF demonstrates remarkable reversible capacity(719 mAh g^(-1)at 0.5 A g^(-1)),along with rapid charging ability(completing a charge in just 127 s).Meanwhile,the assembled full-cell battery manifested exceptional energy density of 165.8 Wh kg^(-1)at a high-power output of 5526 W kg^(-1).This study presents an effective strategy for fabricating highperformance sulphide-based anode materials for SIBs,offering broad prospects for application.
基金supported by the National Natural Science Foundation of China(Nos.52003297 and 22302233)the Open Project of State Key Laboratory of Chemical Safety(No.SKLCS-2024020)+2 种基金the National Key R&D Program of China(Nos.2022YFB3205501 and 2022YFB3205504)and the Fundamental Research Funds for the Central Universities(No.24CX02014A)the Fund of State Key Laboratory of Deep Oil and Gas,China University of Petroleum(East China).
文摘Based on the unique catalytic properties of precious metals,the introduction of precious metals into metal oxide semiconductors will greatly improve the gas-sensitive properties of materials.As a new type of porous material,metal–organic frameworks(MOF)can be used for gas separation and adsorption due to their adjustable pore size and acceptable thermal stability.In this work,the ZIF-71 MOF was synthesized on CuO nanofibers doped with different concentrations of Ru to form a Ru–CuO@ZIF-71 nanocomposite sensor,which was then used for H_(2)S detection.The sensor shows sensitivity to trace amounts of H_(2)S gas(100 ppb),and the response is greatly enhanced at the optimal Ru doping ratio and operating temperature.The introduction of the ZIF-71 membrane can significantly increase the selectivity of the sensor while further improving the sensitivity.Finally,the possible sensing mechanism of the Ru–CuO@ZIF-71 sensor was explored.The enhancement of the H_(2)S gas sensing properties may be attributed to the catalysis of Ru and the formation of the Schottky junction at the Ru–CuO interface.Besides,the calculation based on density functional theory reveals enhanced adsorption capacities of CuO for H_(2)S after Ru doping.Therefore,the Ru–CuO@ZIF-71 sensor has strong application potential in exhaled gas detection and portable detection of H_(2)S gas in industrial environments.
基金financially supported by the Natural Science Foundation of Shandong Province(Nos.ZR2021ME194,2022TSGC2448,and 2023TSGC0545)the Key Technology Research and Development Program of Shandong Province(No.2021ZLGX01).
文摘Carbon-based electromagnetic wave(EMW)absorbing materials attached with metal sulfides famous for good dielectric properties are favored by researchers,which can form heterogeneous interfaces and thus provide supplementary loss mechanisms to make up for the deficiencies of a single material in energy attenuation.Here,Co_(9)S_(8)/Co@coral-like carbon nanofibers(CNFs)/porous carbon hybrids are successfully fabricated by hydrothermal and chemical vapor deposition.The samples have exceptional EMW absorb-ing properties,with a minimum reflection loss of-57.48 dB at a thickness of 2.94 mm and an effective absorption bandwidth of up to 6.10 GHz at only 2.20 mm.The interlocking structure formed by Co@coral-like CNFs,interfacial polarization generated by heterostructure of Co_(9)S_(8),abundant defects and large specific surface area resulted from porous properties are important factors in attaining magnetic-dielectric balance and excellent absorption performance.Different matrixes are selected instead of paraffin to investigate the effect of matrix materials on EMW absorbing capacity.Besides,the EMW attenuation potential for practical applications is also demonstrated by radar cross-section simulations,electric field intensity distribution and power loss density.This work provides a novel strategy for designing outstanding EMW absorbers with unique microstructures using facile and low-cost synthetic routes.
基金supported by the National Natural Science Foundation of China(22222601 and 22076019)the Fundamental Research Funds for the Central Universities(DUT23LAB611).
文摘The Cu^(+)/Cu^(0)sites of copper-based catalysts are crucial for enhancing the production of multicarbon(C_(2+))products from electrochemical CO_(2)reduction reaction(eCO_(2)RR).However,the unstable Cu^(+)and insufficient Cu^(+)/Cu^(0)active sites lead to their limited selectivity and stability for C_(2+)production.Herein,we embedded copper oxide(CuO_(x))particles into porous nitrogen-doped carbon nanofibers(CuO_(x)@PCNF)by pyrolysis of the electrospun fiber film containing ZIF-8 and Cu_(2)O particles.The porous nitrogendoped carbon nanofibers protected and dispersed Cu^(+)species,and its micro porous structure enhanced the interaction between CuO_(x)and reactants during eCO_(2)RR.The obtained CuO_(x)@PCNF created more effective and stable Cu^(+)/Cu^(0)active sites.It showed a high Faradaic efficiency of 62.5%for C_(2+)products in Hcell,which was 2 times higher than that of bare CuO_(x)(~31.1%).Furthermore,it achieved a maximum Faradaic efficiency of 80.7%for C_(2+)products in flow cell.In situ characterization and density functional theory(DFT)calculation confirmed that the N-doped carbon layer protected Cu^(+)from electrochemical reduction and lowered the energy barrier for the dimerization of^(*)CO.Stable and exposed Cu^(+)/Cu^(0)active sites enhanced the enrichment of^(*)CO and promoted the C-C coupling reaction on the catalyst surface,which facilitated the formation of C_(2+)products.
文摘Piezocatalytic hydrogen peroxide(H_(2)O_(2))generation is a promising synthesis method that has received increasing attention;however,the reaction pathway requires further investigation.Here,Bi_(5)Ti_(3)FeO_(15)nanofibers are used to generate H_(2)O_(2)by harvesting mechanical energy,and the reaction pathways are investigated.The H_(2)O_(2)yield over Bi_(5)Ti_(3)FeO_(15)nanofibers steadily increases from 331μmol g1 h1 in the first cycle to 746μmol g1 h1 in the tenth cycle in pure water without a sacrificial agent.Reliable reaction pathways are revealed by monitoring the pH value changes in the reaction solution during the H_(2)O_(2)generation process.In the H_(2)O_(2)generation process,the water oxidation reaction(WOR)provides a large amount of H+in the reaction solution,which promotes the oxygen reduction reaction(ORR)for H_(2)O_(2)generation.Therefore,an efficient synergistic effect between ORR and WOR achieves dual-pathway H_(2)O_(2)generation,contributing to the excellent piezocatalytic performance of Bi_(5)Ti_(3)FeO_(15)nanofibers.Furthermore,mechanistic studies indicate that the piezocatalytic H_(2)O_(2)generation follows the energy band theory.This work not only demonstrates Bi_(5)Ti_(3)FeO_(15)nanofibers as efficient piezocatalysts for H_(2)O_(2)generation but also provides a simple and effective approach to elucidate reaction pathways.This approach can be applied in photocatalytic,tribocatalytic,and electrocatalytic H_(2)O_(2)generation.
基金financially supported by the National Natural Science Foundation of China (No. 22225902, U22A20436, 22209185)National Key Research&Development Program of China (2022YFE0115900, 2023YFA1507101, 2021YFA1501500)+1 种基金the Self-deployment Project Research Program of Haixi Institutes,Chinese Academy of Sciences (No. CXZX-2022-GH04, CXZX-2023-JQ08)Science and Technology Program of Fuzhou (2023-P-009)。
文摘Manganese-based chalcogenides have significant potential as anodes for sodium-ion batteries(SIBs) due to their high theoretical specific capacity, abundant natural reserves, and environmental friendliness. However, their application is hindered by poor cycling stability, resulting from severe volume changes during cycling and slow reaction kinetics due to their complex crystal structure. Here, an efficient and straightforward strategy was employed to in-situ encapsulate single-phase porous nanocubic MnS_(0.5)Se_(0.5) into carbon nanofibers using electrospinning and the hard template method, thus forming a necklace-like porous MnS_(0.5)Se_(0.5)-carbon nanofiber composite(MnS_(0.5)Se_(0.5)@N-CNF). The introduction of Se significantly impacts both the composition and microstructure of MnS_(0.5)Se_(0.5), including lattice distortion that generates additional defects, optimization of chemical bonds, and a nano-spatially confined design. In situ/ex-situ characterization and density functional theory calculations verified that this MnS_(0.5)Se_(0.5)@N-CNF allevi- ates the volume expansion and facilitates the transfer of Na+/electron. As expected, MnS_(0.5)Se_(0.5)@N-CNF anode demonstrates excellent sodium storage performance, characterized by high initial Coulombic efficiency(90.8%), high-rate capability(370.5 m Ahg^(-1) at 10 Ag^(-1)) and long durability(over 5000 cycles at 5 Ag^(-1)). The MnS_(0.5)Se_(0.5)@N-CNF//NVP@C full cell, assembled with MnS_(0.5)Se_(0.5)@N-CNF as anode and Na_(3)V_(2)(PO_4)_(3)@C as cathode, exhibits a high energy density of 254 Wh kg^(-1) can be provided. This work presents a novel strategy to optimize the design of anode materials through structural engineering and Se substitution, while also elucidating the underlying reaction mechanisms.
基金supported by the National Natural Science Foundation of China(No.11904208the Project of Shandong Province Higher Educational Science and Technology Program(No.J18KB098).
文摘The development of efficient,cost-effective catalysts for the oxygen reduction reaction(ORR)is crucial for advancing zinc-air batteries(ZABs).This study presents Fe_(4)N nanoparticles embedded in N-doped carbon nanofibers(Fe_(4)N@CNF-NH_(3))as a highly efficient ORR catalyst.The Fe_(4)N@CNF-NH_(3)catalyst was synthesized via electrospinning,followed by high-temperature annealing in an NH_(3)atmosphere.This electrospinning technique ensured the uniform dispersion of Fe_(4)N nanoparticles within the carbon nanofibers(CNFs),preventing agglomeration and enhancing the availability of active sites.Structural and morphological analyses confirmed the formation of Fe_(4)N nanoparticles with a lattice spacing of 0.213 nm,surrounded by graphitic carbon structures that significantly improved the material’s conductivity and stability.Electrochemical tests demonstrated that Fe_(4)N@CNF-NH_(3)exhibited superior ORR activity,with a half-wave potential of 0.904 V,surpassing that of commercial Pt/C catalysts.This enhanced performance is attributed to the synergistic effects of Fe_(4)N nanoparticles and the conductive carbon framework,which facilitated efficient charge and mass transfer during the ORR process.Density functional theory calculations further revealed that the introduction of CNFs positively shifted the d-band center of Fe atoms,optimizing oxygen intermediate adsorption and lowering energy barriers for ORR.The practical applicability of Fe_(4)N@CNF-NH_(3)was validated through the assembly of both liquid-state and solid-state ZABs,which exhibited excellent cycling stability,high power density,and superior discharge voltage.This study offers a promising strategy for developing highly active,low-cost ORR catalysts and advances the potential for the commercialization of ZABs.
