Carbonized melamine foam has been recognized as a promising material for microwave absorption due to its exceptional thermal stability,lightweight,and remarkable dielectric properties.In this study,we investigated the...Carbonized melamine foam has been recognized as a promising material for microwave absorption due to its exceptional thermal stability,lightweight,and remarkable dielectric properties.In this study,we investigated the impact of nitric acid oxidation on the surface of carbonized melamine foam and its microwave absorption properties.The treated foam exhibits optimal reflection loss of−21.51 dB at 13.20 GHz,with an effective absorption bandwidth of 7.04 GHz.The enhanced absorption properties are primarily attributed to the strengthened dielectric loss,improved impedance matching,and increased polarization losses resulting from the oxidized surfaces.This research demonstrates a promising new approach for research into surface treatments to improve the performances of microwave absorbers.展开更多
Nickel is a heavy metal which has the potential threaten to human＇s health and attracts public concern recently. The carbonized leaf powder is expected as suitable adsorbent for Ni（II） removal became of the composi...Nickel is a heavy metal which has the potential threaten to human＇s health and attracts public concern recently. The carbonized leaf powder is expected as suitable adsorbent for Ni（II） removal became of the composition of some beneficial groups. In this work, carbonized leaf powder was evaluated for its adsorption performance towards Ni（II）. According to the results, adsorbent component, dosage, initial solute concentration, solution pH, temperature and contact time can significantly affect the efficiency of Ni（II） removal. Sips model fits the test results best, and the adsorption capacity towards Ni（II） is determined around 37.62 mg/g. The thermodynamic behaviors reveal the endothermic and spontaneous nature of the adsorption. The free adsorption energy （fluctuate around 8 kJ/mol） predicted by D-R model indicates that the adsorption capacity originated from both physical and chemical adsorption. Room temperature （15-25 ℃） is suitable for Ni（II） removal as well as low energy consumption for temperature enhancement. Further conclusions about the mechanism of chemical adsorption are obtained through analysis of the FT-IR test and XRD spectra, which indicates that the adsorption process occurs predominantly between amine, carbonate, phosphate and nickel ions.展开更多
Carbon quantum dots(CQDs),which contain a core structure composed of sp^(2)carbon,can be used as the reinforcing phase like graphene and carbon nanotubes in metal matrix.In this paper,the CQD/Cu composite material was...Carbon quantum dots(CQDs),which contain a core structure composed of sp^(2)carbon,can be used as the reinforcing phase like graphene and carbon nanotubes in metal matrix.In this paper,the CQD/Cu composite material was prepared by powder metallurgy method.The composite powder was prepared by molecular blending method and ball milling method at first,and then densified into bulk material by spark plasma sintering(SPS).X-ray diffraction,Raman spectroscopy,infrared spectroscopy,and nuclear magnetic resonance were employed to characterize the CQD synthesized under different temperature conditions,and then CQDs with a higher degree of sp^(2)were utilized as the reinforcement to prepare composite materials with different contents.Mechanical properties and electrical conductivity results show that the tensile strength of the 0.2 CQD/Cu composite material is~31%higher than that of the pure copper sample,and the conductivity of 0.4 CQD/Cu is~96%IACS,which is as high as pure copper.TEM and HRTEM results show that good interface bonding of CQD and copper grain is the key to maintaining high mechanical and electrical conductivity.This research provides an important foundation and direction for new carbon materials reinforced metal matrix composites.展开更多
Pitch produced by the lique-faction of coal was divided into two frac-tions:soluble in toluene(TS)and insol-uble in toluene but soluble in pyridine(TI-PS),and their differences in molecu-lar structure and oxidation ac...Pitch produced by the lique-faction of coal was divided into two frac-tions:soluble in toluene(TS)and insol-uble in toluene but soluble in pyridine(TI-PS),and their differences in molecu-lar structure and oxidation activity were studied.Several different carbon materi-als were produced from them by oxida-tion in air(350℃,300 mL/min)fol-lowed by carbonization(1000℃ in Ar),and the effect of the cross-linked structure on their structure and sodium storage properties was investigated.The results showed that the two pitch fractions were obviously different after the air oxidation.The TS fraction with a low degree of condensation and abundant side chains had a stronger oxidation activity and thus introduced more cross-linked oxygen-containing functional groups C(O)―O which prevented carbon layer rearrangement during the carbonization.As a result,a disordered hard carbon with more defects was formed,which improved the electrochemical performance.Therefore,the carbon materials derived from TS(O-TS-1000)had an obvious disordered structure and a larger layer spacing,giving them better sodium storage perform-ance than those derived from the TI-PS fraction(O-TI-PS-1000).The specific capacity of O-TS-1000 was about 250 mAh/g at 20 mA/g,which was 1.67 times higher than that of O-TI-PS-1000(150 mAh/g).展开更多
The design of cost-effective and efficient metal-free carbon-based catalysts for the hydrogen evolution reaction(HER)is of great significance for increasing the production of clean hydrogen by the electrolysis of alka...The design of cost-effective and efficient metal-free carbon-based catalysts for the hydrogen evolution reaction(HER)is of great significance for increasing the production of clean hydrogen by the electrolysis of alkaline water.Precise control of the electronic structure by heteroatom doping has proven to be efficient for increasing catalytic activity.Nevertheless,both the structural characteristics and the underlying mechanism are not well understood,especially for doping with two different atoms,thus limiting the use of these catalysts.We report the production of phosphorus and nitrogen co-doped hollow carbon nanospheres(HCNs)by the copolymerization of pyrrole and aniline at a Triton X-100 micelle-interface,followed by doping with phytic acid and carbonization.The unique pore structure and defect-rich framework of the HCNs expose numerous active sites.Crucially,the combined effect of graphitic nitrogen and phosphorus-carbon bonds modulate the local electronic structure of adjacent C atoms and facilitates electron transfer.As a res-ult,the HCN carbonized at 1100°C exhibited superior HER activity and an outstanding stability(70 h at a current density of 10 mA cm^(−2))in alkaline water,because of the large number of graphitic nitrogen and phosphorus-carbon bonds.展开更多
As an emerging electrochemical energy storage technology,potassium-ion batteries(PIBs),which are considered a“beyond Li-ion”battery system,have attracted tremendous attention due to their potential for providing a h...As an emerging electrochemical energy storage technology,potassium-ion batteries(PIBs),which are considered a“beyond Li-ion”battery system,have attracted tremendous attention due to their potential for providing a high energy density,and having abundant resource,and a low cost.However,their commercialization is hindered by the lack of practical anode materials.Among various reported anodes,conventional carbon materials,including graphite,soft carbon,and hard carbon,have emerged as promising candidates because of their abundance,low cost,high conductivity,and tunable structures.However,these materials have problems such as a low initial Coulombic efficiency,significant volume expansion,and unsatisfactory cyclability and rate performance.Various strategies to solve these have been explored,including optimizing the interlayer spacing,structural design,surface coating,constructing a multifunctional framework,and forming composites.This review provides a comprehensive overview of the recent progress in conventional carbon anodes,highlighting structural design strategies,mechanisms for improving the electrochemical performance,and underscores the critical role of these materials in promoting the practical application of PIBs.展开更多
With the development of electronics and portable devices,there is a significant drive to develop electrode materials for supercapacitors that are lightweight,economical,and provide high energy and power densities.Lign...With the development of electronics and portable devices,there is a significant drive to develop electrode materials for supercapacitors that are lightweight,economical,and provide high energy and power densities.Lignin-based porous carbons have recently been extensively studied for en-ergy storage applications because of their characteristics of large specific surface area,easy doping,and high conductivity.Significant progress in the synthesis of porous carbons derived from lignin,using different strategies for their preparation and modification with heteroatoms,metal oxides,met-al sulfides,and conductive polymers is considered and their electrochemical performances and ion storage mechanisms are discussed.Considerable fo-cus is directed towards the challenges encountered in using lignin-based por-ous carbons and the ways to optimize specific capacity and energy density for supercapacitor applications.Finally,the limitations of existing technolo-gies and research directions for improving the performance of lignin-based carbons are discussed.展开更多
Energy storage is a key factor in the drive for carbon neutrality and carbon nanotubes(CNTs)may have an important role in this.Their intrinsic sp2 covalent structure gives them excellent electrical conductivity,mechan...Energy storage is a key factor in the drive for carbon neutrality and carbon nanotubes(CNTs)may have an important role in this.Their intrinsic sp2 covalent structure gives them excellent electrical conductivity,mechanical strength,and chemical stability,making them suitable for many uses in energy storage,such as lithium-ion batteries(LIBs).Currently,their use in LIBs mainly focuses on conductive networks,current collectors,and dry electrodes.The review outlines advances in the use of CNTs in the cathodes and anodes of LIBs,especially in the electrode fabrication and mechanical sensors,as well as providing insights into their future development.展开更多
Sodium-ion batteries(SIBs)have emerged as a promising contender for next-gener-ation energy storage systems.Hard carbon is re-garded as the most promising anode for commer-cial SIB,however,the large number of defects ...Sodium-ion batteries(SIBs)have emerged as a promising contender for next-gener-ation energy storage systems.Hard carbon is re-garded as the most promising anode for commer-cial SIB,however,the large number of defects on its surface cause irreversible electrolyte consump-tion and an uneven solid electrolyte interphase film.An advanced molecular engineering strategy to coat hard carbon with polycyclic aromatic mo-lecules is reported.Specifically,polystyrene-based carbon microspheres(CSs)were first synthesized and then coated with polycyclic aromatic mo-lecules derived from coal tar pitch by spray-drying and followed by oxidation.Compared to the traditional CVD coating meth-od,this molecular framework strategy has been shown to reduce the number of defects on the surface of CSs without sacrifi-cing internal storage sites and suppressing transport kinetics in hosting the sodium ions.Besides the lower surface defect con-centration,the synthesized hybrid carbon microspheres(HCSs)have a larger grain size and more abundant closed pores,and have a higher reversible sodium storage capacity.A HCS-P-60%electrode has a capacity of 332.3 mAh g^(-1)with an initial Cou-lombic efficiency of 88.5%.It also has a superior rate performance of 246.6 mAh g^(-1)at 2 C and a 95.2%capacity retention after 100 cycles at 0.2 C.This work offers new insights into designing high-performance hard carbon microsphere anodes,advan-cing the commercialization of sodium-ion batteries.展开更多
Lithium-air batteries(LABs)are regarded as a next-generation energy storage option due to their relatively high energy density.The cyclic stability and lifespan of LABs are mainly influenced by the formation and decom...Lithium-air batteries(LABs)are regarded as a next-generation energy storage option due to their relatively high energy density.The cyclic stability and lifespan of LABs are mainly influenced by the formation and decomposition of lithium-based oxides at the air cathode,which not only lead to a low cathode catalytic efficiency but also restrict the electrochemical reversibility and cause side reaction problems.Carbon materials are considered key to solving these problems due to their conductivity,functional flexibility,and adjustable pore structure.This paper considers the research progress on carbon materials as air cathode catalytic materials for LABs,focusing on their structural characteristics,electrochemical behavior,and reaction mechanisms.Besides being used as air cathodes,carbon materials also show potential for being used as protective layers for metal anodes or as anode materials for LABs.展开更多
Changes to the microstructure of a hard carbon(HC)and its solid electrolyte interface(SEI)can be effective in improving the electrode kinetics.However,achieving fast charging using a simple and inexpensive strategy wi...Changes to the microstructure of a hard carbon(HC)and its solid electrolyte interface(SEI)can be effective in improving the electrode kinetics.However,achieving fast charging using a simple and inexpensive strategy without sacrificing its initial Coulombic efficiency remains a challenge in sodium ion batteries.A simple liquid-phase coating approach has been used to generate a pitch-derived soft carbon layer on the HC surface,and its effect on the porosity of HC and SEI chemistry has been studied.A variety of structural characterizations show a soft carbon coating can increase the defect and ultra-micropore contents.The increase in ultra-micropore comes from both the soft carbon coatings and the larger pores within the HC that are partially filled by pitch,which provides more Na+storage sites.In-situ FTIR/EIS and ex-situ XPS showed that the soft carbon coating induced the formation of thinner SEI that is richer in NaF from the electrolyte,which stabilized the interface and promoted the charge transfer process.As a result,the anode produced fastcharging(329.8 mAh g^(−1)at 30 mA g^(−1)and 198.6 mAh g^(−1)at 300 mA g^(−1))and had a better cycling performance(a high capacity retention of 81.4%after 100 cycles at 150 mA g^(−1)).This work reveals the critical role of coating layer in changing the pore structure,SEI chemistry and diffusion kinetics of hard carbon,which enables rational design of sodium-ion battery anode with enhanced fast charging capability.展开更多
To optimize the CO_(2) adsorption performance of carbon materials,this study proposed a preparation method for biomass-based porous carbon through hydrothermal carbonization coupled with nitrogen source optimization a...To optimize the CO_(2) adsorption performance of carbon materials,this study proposed a preparation method for biomass-based porous carbon through hydrothermal carbonization coupled with nitrogen source optimization and K_(2)CO_(3) activation.The effects of different nitrogen sources(urea,piperazine,melamine,and polyaniline)and activation temperatures on the physicochemical features and CO_(2) adsorption characteristics of the porous carbons were systematically investigated.The results indicated that different nitrogen sources showed varying impacts on the CO_(2) uptake of porous carbons,and not all nitrogen sources enhanced the adsorption performance.The urea and piperazine doped porous carbons exhibited relatively low nitrogen contents and specific surface areas.Whereas the melamine doped carbons showed higher nitrogen contents and specific surface areas,but lacked narrow micropores,limiting their CO_(2) adsorption performance.In contrast,PAC-700,prepared using polyaniline as nitrogen source,featured a well-developed pore structure,abundant narrow micropores and pyrrolic-N groups,endowing it with enhanced CO_(2) adsorption capability.At 0℃/1 bar and 25℃/1 bar,the CO_(2) uptake of PAC-700 reached 6.85 and 4.64 mmol/g,respectively.Additionally,PAC-700 maintained a CO_(2) uptake retention ratio of 99%after 5 adsorption-desorption cycles and exhibited good CO_(2)/N_(2) selectivity of 22.4−51.6.These findings highlighted the advantageous CO_(2) adsorption performance of PAC-700,indicating its substantial application potential in the domain of carbon capture.展开更多
Nanomaterials exhibiting mimetic enzyme activity are promising candidates for colorimetric detection of chlorpyrifos.Herein,lignin-based FeN/C nanozymes(FeN/CNs)with peroxidase-like activity were synthesized by a one-...Nanomaterials exhibiting mimetic enzyme activity are promising candidates for colorimetric detection of chlorpyrifos.Herein,lignin-based FeN/C nanozymes(FeN/CNs)with peroxidase-like activity were synthesized by a one-pot method.Within the material,the nitrogen mainly exists as pyrrolyl nitrogen,which coordinates with iron to form an Fe-N structure that serves as the active site.The sensor incorporates acetylcholinesterase(AChE)to facilitate the restoration of oxidized 3,3',5',5'-tetramethylbenzidine(TMB),thereby restoring the blue solution to a color⁃less state.Furthermore,the presence of chlorpyrifos was found to inhibit AChE activity,causing the solution to turn blue again.A sensitive colorimetric method for chlorpyrifos has been established.The linear range of this method for the detection of chlorpyrifos was 0.90-80.00μg·g^(-1) and the limit of detection(LOD)was 0.13μg·g^(-1).When applied to real samples,the method achieved recoveries of 94.4%-109%for chlorpyrifos in soil,and relative standard devia⁃tions(RSD)of the assay were 3.6%-4.2%.Therefore,the constructed sensor holds significant potential for the reli⁃able detection of chlorpyrifos.展开更多
Carbon dots(CDs)are fluorescent carbon-based nanomaterials with sizes smal-ler than 10 nm,that are renowned for their exceptional properties,including superior anti-photobleaching,excellent biocompatibility,and minima...Carbon dots(CDs)are fluorescent carbon-based nanomaterials with sizes smal-ler than 10 nm,that are renowned for their exceptional properties,including superior anti-photobleaching,excellent biocompatibility,and minimal toxicity,which have received sig-nificant interest.Near-infrared(NIR)light has emerged as an ideal light source in the biolo-gical field due to its advantages of minimal scattering and absorption,long wavelength emission,increased tissue penetration,and reduced interference from biological back-grounds.CDs with efficient absorption and/or emission characteristics in the NIR spectrum have shown remarkable promise in the biomedical uses.This study provides a comprehens-ive overview of the preparation methods and wavelength modulation strategies for near-in-frared CDs and reviews research progress in their use in the areas of biosensing,bioimaging,and therapy.It also discusses current challenges and clinical prospects,aimed at deepening our understanding of the subject and promoting further advances in this field.展开更多
Transformation of urea and glycerol to glycerol carbonate is an environmental friendly and economical process.Catalysts play an indispensable role in the process.Although many catalysts have been developed,the perform...Transformation of urea and glycerol to glycerol carbonate is an environmental friendly and economical process.Catalysts play an indispensable role in the process.Although many catalysts have been developed,the performance of the catalysts still cannot meet the needs of industrialization.In this paper,research progress of the homogeneous and heterogeneous catalysts of the reaction over the past 20 years were reviewed systematically.According to the types and active centers of catalysts,the catalysts were classified systematically and analyzed in detail.The typical reaction mechanisms were also summarized.The research and development direction of catalysts is made more explicit through systematic classification and mechanism analysis.The article reveals more novel catalysts have been designed and used for the reaction,such as mixed metal oxides with special structures,solid wastes and non-metallic materials.This work summarized the current state of research and prospected possible routes for design of novel catalysts.It is hoped that this review can provide some references for developing efficient catalysts.展开更多
In this work,iron-doped carbon dots(Fe-CDs)with strong peroxidase-mimicking activity were synthesized for tumor-specific therapy.Their intrinsic red fluorescence enabled high-contrast cellular imaging,revealing prefer...In this work,iron-doped carbon dots(Fe-CDs)with strong peroxidase-mimicking activity were synthesized for tumor-specific therapy.Their intrinsic red fluorescence enabled high-contrast cellular imaging,revealing preferen⁃tial mitochondrial accumulation.In the acidic and hydrogen peroxide(H_(2)O_(2))-rich tumor microenvironment,Fe-CDs catalyzed hydroxyl radical(·OH)generation,inducing oxidative stress and lipid peroxidation,ultimately triggering ferroptosis.In vitro and in vivo studies demonstrated potent tumor inhibition.Furthermore,Fe-CDs exhibited excel⁃lent biocompatibility with no significant systemic toxicity.By integrating fluorescence imaging and catalytic therapy,this study presents a promising nanoplatform for tumor treatment and ferroptosis research.展开更多
Graphitic carbon nitride(g-C_(3)N_(4))exhibits great mechanical as well as thermal characteristics,making it a valuable ma-terial for use in photoelectric conversion devices,an accelerator for synthesis of organic com...Graphitic carbon nitride(g-C_(3)N_(4))exhibits great mechanical as well as thermal characteristics,making it a valuable ma-terial for use in photoelectric conversion devices,an accelerator for synthesis of organic compounds,an electrolyte for fuel cell applications or power sources,and a hydrogen storage substance and a fluorescence detector.It is fabricated using dif-ferent methods,and there is a variety of morphologies and nanostructures such as zero to three dimensions that have been designed for different purposes.Ther e are many reports about g-C_(3)N_(4) in recent years,but a comprehensive review which covers nanostructure dimensions and their properties are missing.This review paper aims to give basic and comprehensive understanding of the photocatalytic and electrocatalytic usages of g-C_(3)N_(4).It highlights the recent progress of g-C_(3)N_(4) nano-structure designing by covering synthesis methods,dimensions,morphologies,applications and properties.Along with the summary,we will also discuss the challenges and prospects.Scientists,investigators,and engineers looking at g-C_(3)N_(4) nanostructures for a variety of applications might find our review paper to be a useful resource.展开更多
Carbon materials are a key component in energy storage and conversion devices and their microstructure plays a crucial role in determining device performance.However,traditional carbon materials are unable to meet the...Carbon materials are a key component in energy storage and conversion devices and their microstructure plays a crucial role in determining device performance.However,traditional carbon materials are unable to meet the requirements for applications in emerging fields such as renewable energy and electric vehicles due to limitations including a disordered structure and uncontrolled defects.With an aim of realizing devisable structures,adjustable functions,and performance breakthroughs,superstructured carbons is proposed and represent a category of carbon-based materials,characterized by precisely-built pores,networks,and interfaces.Superstructured carbons can overcome the limitations of traditional carbon materials and improve the performance of energy storage and conversion devices.We review the structure-activity relationships of superstructured carbons and recent research advances from three aspects including a precisely customized pore structure,a dense carbon network framework,and a multi-component highly coupled interface between the different components.Finally,we provide an outlook on the future development of and practical challenges in energy storage and conversion devices.展开更多
This data set collects,compares and contrasts the capacities and structures of a series of hard carbon materials,and then searches for correlations between structure and electrochemical performance.The capacity data o...This data set collects,compares and contrasts the capacities and structures of a series of hard carbon materials,and then searches for correlations between structure and electrochemical performance.The capacity data of the hard carbons were obtained by charge/discharge tests and the materials were characterized by XRD,gas adsorption,true density tests and SAXS.In particular,the fitting of SAXS gave a series of structural parameters which showed good characterization.The related test details are given with the structural data of the hard carbons and the electrochemical performance of the sodium-ion batteries.展开更多
基金Project(2023RC3066)supported by the Science and Technology Innovation Program of Hunan Province,ChinaProject(2023JJ50079)supported by the Hunan Provincial Natural Science Foundation,China。
文摘Carbonized melamine foam has been recognized as a promising material for microwave absorption due to its exceptional thermal stability,lightweight,and remarkable dielectric properties.In this study,we investigated the impact of nitric acid oxidation on the surface of carbonized melamine foam and its microwave absorption properties.The treated foam exhibits optimal reflection loss of−21.51 dB at 13.20 GHz,with an effective absorption bandwidth of 7.04 GHz.The enhanced absorption properties are primarily attributed to the strengthened dielectric loss,improved impedance matching,and increased polarization losses resulting from the oxidized surfaces.This research demonstrates a promising new approach for research into surface treatments to improve the performances of microwave absorbers.
基金Projects(5117916851308310)supported by the National Natural Science Foundation of China+1 种基金Project(LQ13E080007)supported by Zhejiang Provincial Natural Science Foundation,ChinaProject supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholars of Jiangsu Province,China
文摘Nickel is a heavy metal which has the potential threaten to human＇s health and attracts public concern recently. The carbonized leaf powder is expected as suitable adsorbent for Ni（II） removal became of the composition of some beneficial groups. In this work, carbonized leaf powder was evaluated for its adsorption performance towards Ni（II）. According to the results, adsorbent component, dosage, initial solute concentration, solution pH, temperature and contact time can significantly affect the efficiency of Ni（II） removal. Sips model fits the test results best, and the adsorption capacity towards Ni（II） is determined around 37.62 mg/g. The thermodynamic behaviors reveal the endothermic and spontaneous nature of the adsorption. The free adsorption energy （fluctuate around 8 kJ/mol） predicted by D-R model indicates that the adsorption capacity originated from both physical and chemical adsorption. Room temperature （15-25 ℃） is suitable for Ni（II） removal as well as low energy consumption for temperature enhancement. Further conclusions about the mechanism of chemical adsorption are obtained through analysis of the FT-IR test and XRD spectra, which indicates that the adsorption process occurs predominantly between amine, carbonate, phosphate and nickel ions.
基金Project(52064032)supported by the National Natural Science Foundation of ChinaProjects(2019ZE001,202002AB080001)supported by the Yunnan Science and Technology Projects,ChinaProject(YNWR-QNBJ-2018-005)supported by the Yunnan Ten Thousand Talents Plan Young&Elite Talents,China。
文摘Carbon quantum dots(CQDs),which contain a core structure composed of sp^(2)carbon,can be used as the reinforcing phase like graphene and carbon nanotubes in metal matrix.In this paper,the CQD/Cu composite material was prepared by powder metallurgy method.The composite powder was prepared by molecular blending method and ball milling method at first,and then densified into bulk material by spark plasma sintering(SPS).X-ray diffraction,Raman spectroscopy,infrared spectroscopy,and nuclear magnetic resonance were employed to characterize the CQD synthesized under different temperature conditions,and then CQDs with a higher degree of sp^(2)were utilized as the reinforcement to prepare composite materials with different contents.Mechanical properties and electrical conductivity results show that the tensile strength of the 0.2 CQD/Cu composite material is~31%higher than that of the pure copper sample,and the conductivity of 0.4 CQD/Cu is~96%IACS,which is as high as pure copper.TEM and HRTEM results show that good interface bonding of CQD and copper grain is the key to maintaining high mechanical and electrical conductivity.This research provides an important foundation and direction for new carbon materials reinforced metal matrix composites.
文摘Pitch produced by the lique-faction of coal was divided into two frac-tions:soluble in toluene(TS)and insol-uble in toluene but soluble in pyridine(TI-PS),and their differences in molecu-lar structure and oxidation activity were studied.Several different carbon materi-als were produced from them by oxida-tion in air(350℃,300 mL/min)fol-lowed by carbonization(1000℃ in Ar),and the effect of the cross-linked structure on their structure and sodium storage properties was investigated.The results showed that the two pitch fractions were obviously different after the air oxidation.The TS fraction with a low degree of condensation and abundant side chains had a stronger oxidation activity and thus introduced more cross-linked oxygen-containing functional groups C(O)―O which prevented carbon layer rearrangement during the carbonization.As a result,a disordered hard carbon with more defects was formed,which improved the electrochemical performance.Therefore,the carbon materials derived from TS(O-TS-1000)had an obvious disordered structure and a larger layer spacing,giving them better sodium storage perform-ance than those derived from the TI-PS fraction(O-TI-PS-1000).The specific capacity of O-TS-1000 was about 250 mAh/g at 20 mA/g,which was 1.67 times higher than that of O-TI-PS-1000(150 mAh/g).
基金financially supported by the project of the National Natural Science Foundation of China(52322203)the Key Research and Development Program of Shaanxi Province(2024GHZDXM-21)。
文摘The design of cost-effective and efficient metal-free carbon-based catalysts for the hydrogen evolution reaction(HER)is of great significance for increasing the production of clean hydrogen by the electrolysis of alkaline water.Precise control of the electronic structure by heteroatom doping has proven to be efficient for increasing catalytic activity.Nevertheless,both the structural characteristics and the underlying mechanism are not well understood,especially for doping with two different atoms,thus limiting the use of these catalysts.We report the production of phosphorus and nitrogen co-doped hollow carbon nanospheres(HCNs)by the copolymerization of pyrrole and aniline at a Triton X-100 micelle-interface,followed by doping with phytic acid and carbonization.The unique pore structure and defect-rich framework of the HCNs expose numerous active sites.Crucially,the combined effect of graphitic nitrogen and phosphorus-carbon bonds modulate the local electronic structure of adjacent C atoms and facilitates electron transfer.As a res-ult,the HCN carbonized at 1100°C exhibited superior HER activity and an outstanding stability(70 h at a current density of 10 mA cm^(−2))in alkaline water,because of the large number of graphitic nitrogen and phosphorus-carbon bonds.
文摘As an emerging electrochemical energy storage technology,potassium-ion batteries(PIBs),which are considered a“beyond Li-ion”battery system,have attracted tremendous attention due to their potential for providing a high energy density,and having abundant resource,and a low cost.However,their commercialization is hindered by the lack of practical anode materials.Among various reported anodes,conventional carbon materials,including graphite,soft carbon,and hard carbon,have emerged as promising candidates because of their abundance,low cost,high conductivity,and tunable structures.However,these materials have problems such as a low initial Coulombic efficiency,significant volume expansion,and unsatisfactory cyclability and rate performance.Various strategies to solve these have been explored,including optimizing the interlayer spacing,structural design,surface coating,constructing a multifunctional framework,and forming composites.This review provides a comprehensive overview of the recent progress in conventional carbon anodes,highlighting structural design strategies,mechanisms for improving the electrochemical performance,and underscores the critical role of these materials in promoting the practical application of PIBs.
基金National Natural Science Foundation of China(22262034)。
文摘With the development of electronics and portable devices,there is a significant drive to develop electrode materials for supercapacitors that are lightweight,economical,and provide high energy and power densities.Lignin-based porous carbons have recently been extensively studied for en-ergy storage applications because of their characteristics of large specific surface area,easy doping,and high conductivity.Significant progress in the synthesis of porous carbons derived from lignin,using different strategies for their preparation and modification with heteroatoms,metal oxides,met-al sulfides,and conductive polymers is considered and their electrochemical performances and ion storage mechanisms are discussed.Considerable fo-cus is directed towards the challenges encountered in using lignin-based por-ous carbons and the ways to optimize specific capacity and energy density for supercapacitor applications.Finally,the limitations of existing technolo-gies and research directions for improving the performance of lignin-based carbons are discussed.
文摘Energy storage is a key factor in the drive for carbon neutrality and carbon nanotubes(CNTs)may have an important role in this.Their intrinsic sp2 covalent structure gives them excellent electrical conductivity,mechanical strength,and chemical stability,making them suitable for many uses in energy storage,such as lithium-ion batteries(LIBs).Currently,their use in LIBs mainly focuses on conductive networks,current collectors,and dry electrodes.The review outlines advances in the use of CNTs in the cathodes and anodes of LIBs,especially in the electrode fabrication and mechanical sensors,as well as providing insights into their future development.
文摘Sodium-ion batteries(SIBs)have emerged as a promising contender for next-gener-ation energy storage systems.Hard carbon is re-garded as the most promising anode for commer-cial SIB,however,the large number of defects on its surface cause irreversible electrolyte consump-tion and an uneven solid electrolyte interphase film.An advanced molecular engineering strategy to coat hard carbon with polycyclic aromatic mo-lecules is reported.Specifically,polystyrene-based carbon microspheres(CSs)were first synthesized and then coated with polycyclic aromatic mo-lecules derived from coal tar pitch by spray-drying and followed by oxidation.Compared to the traditional CVD coating meth-od,this molecular framework strategy has been shown to reduce the number of defects on the surface of CSs without sacrifi-cing internal storage sites and suppressing transport kinetics in hosting the sodium ions.Besides the lower surface defect con-centration,the synthesized hybrid carbon microspheres(HCSs)have a larger grain size and more abundant closed pores,and have a higher reversible sodium storage capacity.A HCS-P-60%electrode has a capacity of 332.3 mAh g^(-1)with an initial Cou-lombic efficiency of 88.5%.It also has a superior rate performance of 246.6 mAh g^(-1)at 2 C and a 95.2%capacity retention after 100 cycles at 0.2 C.This work offers new insights into designing high-performance hard carbon microsphere anodes,advan-cing the commercialization of sodium-ion batteries.
文摘Lithium-air batteries(LABs)are regarded as a next-generation energy storage option due to their relatively high energy density.The cyclic stability and lifespan of LABs are mainly influenced by the formation and decomposition of lithium-based oxides at the air cathode,which not only lead to a low cathode catalytic efficiency but also restrict the electrochemical reversibility and cause side reaction problems.Carbon materials are considered key to solving these problems due to their conductivity,functional flexibility,and adjustable pore structure.This paper considers the research progress on carbon materials as air cathode catalytic materials for LABs,focusing on their structural characteristics,electrochemical behavior,and reaction mechanisms.Besides being used as air cathodes,carbon materials also show potential for being used as protective layers for metal anodes or as anode materials for LABs.
基金National Key Research and Development Program of China(2022YFE0206300)National Natural Science Foundation of China(U21A2081,22075074,22209047)+2 种基金Guangdong Basic and Applied Basic Research Foundation(2024A1515011620)Hunan Provincial Natural Science Foundation of China(2024JJ5068)Foundation of Yuelushan Center for Industrial Innovation(2023YCII0119)。
文摘Changes to the microstructure of a hard carbon(HC)and its solid electrolyte interface(SEI)can be effective in improving the electrode kinetics.However,achieving fast charging using a simple and inexpensive strategy without sacrificing its initial Coulombic efficiency remains a challenge in sodium ion batteries.A simple liquid-phase coating approach has been used to generate a pitch-derived soft carbon layer on the HC surface,and its effect on the porosity of HC and SEI chemistry has been studied.A variety of structural characterizations show a soft carbon coating can increase the defect and ultra-micropore contents.The increase in ultra-micropore comes from both the soft carbon coatings and the larger pores within the HC that are partially filled by pitch,which provides more Na+storage sites.In-situ FTIR/EIS and ex-situ XPS showed that the soft carbon coating induced the formation of thinner SEI that is richer in NaF from the electrolyte,which stabilized the interface and promoted the charge transfer process.As a result,the anode produced fastcharging(329.8 mAh g^(−1)at 30 mA g^(−1)and 198.6 mAh g^(−1)at 300 mA g^(−1))and had a better cycling performance(a high capacity retention of 81.4%after 100 cycles at 150 mA g^(−1)).This work reveals the critical role of coating layer in changing the pore structure,SEI chemistry and diffusion kinetics of hard carbon,which enables rational design of sodium-ion battery anode with enhanced fast charging capability.
基金supported by the National Key R&D Program(2022YFC3902403)Fundamental Research Funds for the Central Universities(2024JC001,2019JG002)Technology Innovation Special Fund of Jiangsu Province for Carbon Dioxide Emission Peaking and Carbon Neutrality(BE2022307)。
文摘To optimize the CO_(2) adsorption performance of carbon materials,this study proposed a preparation method for biomass-based porous carbon through hydrothermal carbonization coupled with nitrogen source optimization and K_(2)CO_(3) activation.The effects of different nitrogen sources(urea,piperazine,melamine,and polyaniline)and activation temperatures on the physicochemical features and CO_(2) adsorption characteristics of the porous carbons were systematically investigated.The results indicated that different nitrogen sources showed varying impacts on the CO_(2) uptake of porous carbons,and not all nitrogen sources enhanced the adsorption performance.The urea and piperazine doped porous carbons exhibited relatively low nitrogen contents and specific surface areas.Whereas the melamine doped carbons showed higher nitrogen contents and specific surface areas,but lacked narrow micropores,limiting their CO_(2) adsorption performance.In contrast,PAC-700,prepared using polyaniline as nitrogen source,featured a well-developed pore structure,abundant narrow micropores and pyrrolic-N groups,endowing it with enhanced CO_(2) adsorption capability.At 0℃/1 bar and 25℃/1 bar,the CO_(2) uptake of PAC-700 reached 6.85 and 4.64 mmol/g,respectively.Additionally,PAC-700 maintained a CO_(2) uptake retention ratio of 99%after 5 adsorption-desorption cycles and exhibited good CO_(2)/N_(2) selectivity of 22.4−51.6.These findings highlighted the advantageous CO_(2) adsorption performance of PAC-700,indicating its substantial application potential in the domain of carbon capture.
基金The Fundamental Research Funds for the Central Universities(2572022DJ01)Natural Science Foundation of Heilongjiang Province(LH2022B002)。
文摘Nanomaterials exhibiting mimetic enzyme activity are promising candidates for colorimetric detection of chlorpyrifos.Herein,lignin-based FeN/C nanozymes(FeN/CNs)with peroxidase-like activity were synthesized by a one-pot method.Within the material,the nitrogen mainly exists as pyrrolyl nitrogen,which coordinates with iron to form an Fe-N structure that serves as the active site.The sensor incorporates acetylcholinesterase(AChE)to facilitate the restoration of oxidized 3,3',5',5'-tetramethylbenzidine(TMB),thereby restoring the blue solution to a color⁃less state.Furthermore,the presence of chlorpyrifos was found to inhibit AChE activity,causing the solution to turn blue again.A sensitive colorimetric method for chlorpyrifos has been established.The linear range of this method for the detection of chlorpyrifos was 0.90-80.00μg·g^(-1) and the limit of detection(LOD)was 0.13μg·g^(-1).When applied to real samples,the method achieved recoveries of 94.4%-109%for chlorpyrifos in soil,and relative standard devia⁃tions(RSD)of the assay were 3.6%-4.2%.Therefore,the constructed sensor holds significant potential for the reli⁃able detection of chlorpyrifos.
基金financial support by Talent Introduction Research Initiation Fund of Shanxi Bethune Hospital(2022RC04)Basic Research Program Youth Science Research Project of Shanxi province(202203021212096)+1 种基金Shanxi Province Clinical Theranostics Technology Innovation Center for Immunologic and Rheumatic Diseases(CXZX-202302)Research Project Plan of Shanxi Provincial Administration of Traditional Chinese Medicine(2023ZYYB2021)。
文摘Carbon dots(CDs)are fluorescent carbon-based nanomaterials with sizes smal-ler than 10 nm,that are renowned for their exceptional properties,including superior anti-photobleaching,excellent biocompatibility,and minimal toxicity,which have received sig-nificant interest.Near-infrared(NIR)light has emerged as an ideal light source in the biolo-gical field due to its advantages of minimal scattering and absorption,long wavelength emission,increased tissue penetration,and reduced interference from biological back-grounds.CDs with efficient absorption and/or emission characteristics in the NIR spectrum have shown remarkable promise in the biomedical uses.This study provides a comprehens-ive overview of the preparation methods and wavelength modulation strategies for near-in-frared CDs and reviews research progress in their use in the areas of biosensing,bioimaging,and therapy.It also discusses current challenges and clinical prospects,aimed at deepening our understanding of the subject and promoting further advances in this field.
基金supported by Fundamental Research Program of Shanxi Province(202203021221303)。
文摘Transformation of urea and glycerol to glycerol carbonate is an environmental friendly and economical process.Catalysts play an indispensable role in the process.Although many catalysts have been developed,the performance of the catalysts still cannot meet the needs of industrialization.In this paper,research progress of the homogeneous and heterogeneous catalysts of the reaction over the past 20 years were reviewed systematically.According to the types and active centers of catalysts,the catalysts were classified systematically and analyzed in detail.The typical reaction mechanisms were also summarized.The research and development direction of catalysts is made more explicit through systematic classification and mechanism analysis.The article reveals more novel catalysts have been designed and used for the reaction,such as mixed metal oxides with special structures,solid wastes and non-metallic materials.This work summarized the current state of research and prospected possible routes for design of novel catalysts.It is hoped that this review can provide some references for developing efficient catalysts.
文摘In this work,iron-doped carbon dots(Fe-CDs)with strong peroxidase-mimicking activity were synthesized for tumor-specific therapy.Their intrinsic red fluorescence enabled high-contrast cellular imaging,revealing preferen⁃tial mitochondrial accumulation.In the acidic and hydrogen peroxide(H_(2)O_(2))-rich tumor microenvironment,Fe-CDs catalyzed hydroxyl radical(·OH)generation,inducing oxidative stress and lipid peroxidation,ultimately triggering ferroptosis.In vitro and in vivo studies demonstrated potent tumor inhibition.Furthermore,Fe-CDs exhibited excel⁃lent biocompatibility with no significant systemic toxicity.By integrating fluorescence imaging and catalytic therapy,this study presents a promising nanoplatform for tumor treatment and ferroptosis research.
基金M Tahir is funded by EU H2020 Marie Skłodows-ka-Curie Fellowship(1439425).
文摘Graphitic carbon nitride(g-C_(3)N_(4))exhibits great mechanical as well as thermal characteristics,making it a valuable ma-terial for use in photoelectric conversion devices,an accelerator for synthesis of organic compounds,an electrolyte for fuel cell applications or power sources,and a hydrogen storage substance and a fluorescence detector.It is fabricated using dif-ferent methods,and there is a variety of morphologies and nanostructures such as zero to three dimensions that have been designed for different purposes.Ther e are many reports about g-C_(3)N_(4) in recent years,but a comprehensive review which covers nanostructure dimensions and their properties are missing.This review paper aims to give basic and comprehensive understanding of the photocatalytic and electrocatalytic usages of g-C_(3)N_(4).It highlights the recent progress of g-C_(3)N_(4) nano-structure designing by covering synthesis methods,dimensions,morphologies,applications and properties.Along with the summary,we will also discuss the challenges and prospects.Scientists,investigators,and engineers looking at g-C_(3)N_(4) nanostructures for a variety of applications might find our review paper to be a useful resource.
文摘Carbon materials are a key component in energy storage and conversion devices and their microstructure plays a crucial role in determining device performance.However,traditional carbon materials are unable to meet the requirements for applications in emerging fields such as renewable energy and electric vehicles due to limitations including a disordered structure and uncontrolled defects.With an aim of realizing devisable structures,adjustable functions,and performance breakthroughs,superstructured carbons is proposed and represent a category of carbon-based materials,characterized by precisely-built pores,networks,and interfaces.Superstructured carbons can overcome the limitations of traditional carbon materials and improve the performance of energy storage and conversion devices.We review the structure-activity relationships of superstructured carbons and recent research advances from three aspects including a precisely customized pore structure,a dense carbon network framework,and a multi-component highly coupled interface between the different components.Finally,we provide an outlook on the future development of and practical challenges in energy storage and conversion devices.
基金supported by the National Natural Science Foundation of China(22379157)CAS Project for Young Scientists in Basic Research(YSBR-102)+2 种基金Institute of Coal Chemistry,Chinese Academy of Sciences(SCJC-XCL-2023-13,SCJCXCL-2023-10)Talent Projects for Outstanding Doctoral Students to Work in Shanxi Province(E3SWR4791Z)Fundamental Research Program of Shanxi Province(202403021222485).
文摘This data set collects,compares and contrasts the capacities and structures of a series of hard carbon materials,and then searches for correlations between structure and electrochemical performance.The capacity data of the hard carbons were obtained by charge/discharge tests and the materials were characterized by XRD,gas adsorption,true density tests and SAXS.In particular,the fitting of SAXS gave a series of structural parameters which showed good characterization.The related test details are given with the structural data of the hard carbons and the electrochemical performance of the sodium-ion batteries.
