The defect-free structure of Mo-based materials is a“double-edged sword”,which endows the material with excellent stability,but limits its chemical versatility and application in electrochemical hydrogen evolution r...The defect-free structure of Mo-based materials is a“double-edged sword”,which endows the material with excellent stability,but limits its chemical versatility and application in electrochemical hydrogen evolution reaction(HER).Carbon doping engineering is an attractive strategy to effectively improve the performance of Mo-based catalyst and maintain their stability.Herein,we report a cross-linked porous carbon-doped MoO_(2)(C–MoO_(2))-based catalyst Ru/C–MoO_(2) for electrochemical HER,which is prepared by the convenient redox solid-phase reaction(SPR)of porous RuO_(2)/Mo_(2)C composite precursor.Theoretical studies reveal that due to the presence of carbon atoms,the electronic structure of C–MoO_(2) has been properly adjusted,and the loaded small Ru nanoparticles provide a fast water dissociation rate and moderate H adsorption strength.In electrochemical studies under a pH-universal environment,Ru/C–MoO_(2) electrocatalyst exhibits a low overpotential at a current density of 10 mA cm^(-2) and has a low Tafel slope.Meanwhile,Ru/C-MoO_(2) has excellent stability for more than 100 h at an initial current density of 100 mA cm^(-2).展开更多
Nitrogen and/or carbon doped titania photocatalysts were prepared by a novel mechanochemical method. The prepared powders possessed two absorption edges around 400 and 540 nm wavelengths and showed excellent photocata...Nitrogen and/or carbon doped titania photocatalysts were prepared by a novel mechanochemical method. The prepared powders possessed two absorption edges around 400 and 540 nm wavelengths and showed excellent photocatalytic ability for nitrogen monoxide oxidation under visible light irradiation. Under the irradiation of visible light of wavelength >510 nm,37% of nitrogen monoxide could be continuously removed by the carbon and nitrogen co-doped titania prepared by planetary ball milling of P-25 titania–10% hexamethylenetetramine mixture followed by calcination in air at 400-C.展开更多
The"one pot"simultaneous carbon coating and doping of TiO_(2) materials by the hydrolysis of TiCl4 in fructose is reported.The synergistic effect of carbon doping and coating of TiO_(2) to significantly boos...The"one pot"simultaneous carbon coating and doping of TiO_(2) materials by the hydrolysis of TiCl4 in fructose is reported.The synergistic effect of carbon doping and coating of TiO_(2) to significantly boost textural,optical and electronic properties and photocurrent of TiO_(2) for high performance visible light H2 production from water splitting has been comprehensively investigated.Carbon doping can significantly increase the thermal stability,thus inhibiting the phase transformation of the Titania material from anatase to rutile while carbon coating can suppress the grain aggregation of TiO_(2).The synergy of carbon doping and coating can not only ensure an enhanced narrowing effect of the electronic band gap of TiO_(2) thus extending the absorption of photocatalysts to the visible regions,but also promote dramatically the separation of electron-hole pairs.Owing to these synergistic effects,the carbon coated and doped TiO_(2) shows much superior photocatalytic activity for both degradation of organics and photocatalytic/photoelectro chemical(PEC)water splitting under simulated sunlight illumination.The photocatalytic activity of obtained materials can reach 5,4 and 2 times higher than that of pristine TiO_(2),carbon doped TiO_(2) and carbon coated TiO_(2),respectively in the degradation of organic pollutants.The carbon coated and doped TiO_(2) materials exhibited more than 37 times and hundreds of times photocurrent enhancement under simulated sunlight and visible light,respectively compared to that of pristine TiO_(2).The present work providing new comprehensive understanding on carbon coating and doping effect could be very helpful for the development of advanced TiO_(2) materials for a large series of applications.展开更多
The magnetic and electronic properties of strontium titanate with different carbon dopant configurations are explored using first-principles calculations with a generalized gradient approximation(GGA)and the GGA+U app...The magnetic and electronic properties of strontium titanate with different carbon dopant configurations are explored using first-principles calculations with a generalized gradient approximation(GGA)and the GGA+U approach.Our results show that the structural stability,electronic properties and magnetic properties of C-doped SrTiO3 strongly depend on the distance between carbon dopants.In both GGA and GGA+U calculations,the doping structure is mostly stable with a nonmagnetic feature when the carbon dopants are nearest neighbors,which can be ascribed to the formation of a C–C dimer pair accompanied by stronger C–C and weaker C–Ti hybridizations as the C–C distance becomes smaller.As the C–C distance increases,C-doped SrTiO3 changes from an n-type nonmagnetic metal to ferromagnetic/antiferromagnetic half-metal and to an antiferromagnetic/ferromagnetic semiconductor in GGA calculations,while it changes from a nonmagnetic semiconductor to ferromagnetic half-metal and to an antiferromagnetic semiconductor using the GGA+U method.Our work demonstrates the possibility of tailoring the magnetic and electronic properties of C-doped SrTiO3,which might provide some guidance to extend the applications of strontium titanate as a magnetic or optoelectronic material.展开更多
Efficacious regulation of the geometric and electronic structures of carbon nanomaterials via the introduction of defects and their synergy is essential to achieving good electrochemical performance.However,the guidel...Efficacious regulation of the geometric and electronic structures of carbon nanomaterials via the introduction of defects and their synergy is essential to achieving good electrochemical performance.However,the guidelines for designing hybrid materials with advantageous structures and the fundamental understanding of their electrocatalytic mechanisms remain unclear.Herein,superfine Pt and PtCu nanoparticles supported by novel S,N‐co‐doped multi‐walled CNT(MWCNTs)were prepared through the innovative pyrolysis of a poly(3,4‐ethylenedioxythiophene)/polyaniline copolymer as a source of S and N.The uniform wrapping of the copolymer around the MWCNTs provides a high density of evenly distributed defects on the surface after the pyrolysis treatment,facilitating the uniform distribution of ultrafine Pt and PtCu nanoparticles.Remarkably,the Pt_(1)Cu_(2)/SN‐MWCNTs show an obviously larger electroactive surface area and higher mass activity,stability,and CO poisoning resistance in methanol oxidation compared to Pt/SN‐MWCNTs,Pt/S‐MWCNTs,Pt/N‐MWCNTs,and commercial Pt/C.Density functional theory studies confirm that the co‐doping of S and N considerably deforms the CNTs and polarizes the adjacent C atoms.Consequently,both the adsorption of Pt1Cu2 onto the SN‐MWCNTs and the subsequent adsorption of methanol are enhanced;in addition,the catalytic activity of Pt_(1)Cu_(2)/SN‐MWCNTs for methanol oxidation is thermodynamically and kinetically more favorable than that of its CNT and N‐CNT counterparts.This work provides a novel method to fabricate high‐performance fuel cell electrocatalysts with highly dispersed and stable Pt‐based nanoparticles on a carbon substrate.展开更多
Alpha nickel hydroxide has better performances than commercial beta nickel hydroxide. However, the main defect is that α-phase is difficult to synthesize and easily transformed to β-phase Ni（OH）2 upon aging in a s...Alpha nickel hydroxide has better performances than commercial beta nickel hydroxide. However, the main defect is that α-phase is difficult to synthesize and easily transformed to β-phase Ni（OH）2 upon aging in a strong alkaline solution. In this study, the Al-Co, Al-Yb, Yb-Co and Al-Yb-Co multiple doping was used respectively. By controlling the amount of sodium carbonate, the α-Ni（OH）2 was prepared by ultrasonic-assisted precipitation. And the influence of sodium carbonate on the crystalline phase and structure stability for alpha nickel hydroxide was studied. The results demonstrate that, with increasing amount, the biphase nickel hydroxide transforms to pure alpha nickel hydroxide gradually, and the structure stability is also improved. When the amount of sodium carbonate is 2 g, the sample still keeps α-Ni（OH）2 after being aged for 30 days, for Al-Yb-Co-Ni（OH）2. And when the amount is less than 2 g, the phase transformations exist in the samples with different extents. These results demonstrated that the amount of sodium carbonate is a critical factor to maintain the structural stability of α-Ni（OH）2.展开更多
We used the natural product chamomile as a carbon source to synthesize praseodymium(Pr) and nitrogen(N) co-doped biomass carbon dots(Pr/N-BCDs) with remarkable luminescence properties by one-step hydrothermal method.C...We used the natural product chamomile as a carbon source to synthesize praseodymium(Pr) and nitrogen(N) co-doped biomass carbon dots(Pr/N-BCDs) with remarkable luminescence properties by one-step hydrothermal method.Compared with single N-doped BCDs(N-BCDs) and Pr-doped BCDs(Pr-BCDs),Pr/N-BCDs not only showed better fluorescence properties and stability but also achieved a significant increase in quantum yield of 12%.More importantly,under certain conditions,Pr/N-BCDs and 2,4-dinitrophenylhydrazide(2,4-DNPH) had significant fluorescence internal filtration effect(IFE) and dynamic quenching effect,and in the concentration range of0.50-20 μmol·L^(-1),the concentration of 2,4-DNPH had a good linear relationship with the fluorescence quenching signal,and the detection limit was as low as 2.1 nmol·L^(-1).展开更多
The novel fabrication of multiple components and unique heterostructure can inject infinite vitality into the electromagnetic wave(EMW)attenuation field.Herein,through the self-assembly of polyimide com-plexes and cat...The novel fabrication of multiple components and unique heterostructure can inject infinite vitality into the electromagnetic wave(EMW)attenuation field.Herein,through the self-assembly of polyimide com-plexes and catalytic chemical vapor deposition,porous carbon microflowers were synthesized accompa-nied by carbon nanotubes(CNTs).By regulating the metal ions,the composition and structure of the as-obtained hybrids are modified correspondingly,and thus the adjustable thermal management and EMW absorption capabilities are obtained.In detail,the rich pores and huge specific surface area endow the hierarchical structures with distinguished thermal insulation ability(λ<0.07).The carbon framework and CNTs are beneficial for consuming EMWs via conductive loss and defect polarization loss while reduc-ing the filling ratio and thickness.The doped heteroatoms and abundant heterointerfaces generate ample dipole polarization and interface polarization losses(supported by DFT calculation).The metal nanopar-ticles uniformly embedded in the carbon framework offer optimized impedance matching,proper de-fect polarization,and suitable magnetic loss.Accordingly,the synergy of magnetic-dielectric balance and flower-like superstructure enables FNCFN2 and NNCFN2 to accomplish remarkable microwave absorbing capacity with thin thickness(14 wt.%).Therefore,respectable specific reflection loss and specific effec-tive absorption bandwidth are acquired(215.39 dB mm^(-1) and 22.10 GHz mm^(-1),257.23 dB mm^(-1) and 22.12 GHz mm^(-1) respectively),superior to those of certain renowned carbon-based absorbers.The simu-lation results of electric field intensity distributions,power loss density,and radar cross section reduction(maximum value of 36.02 dBm2)also verify the prominent radar stealth capability.Moreover,the cus-tomizable approach can be applied to other metals to obtain fulfilling behaviors.Henceforth,this work provides profound insights into the relationship between structure and performance,and proposes an efficient path for mass-producing multifunctional and high-performance EMW absorbers with excellent thermal properties.展开更多
The previous studies mainly focused on improving microwave absorbing(MA)performances of MA materials.Even so,these designed MA materials were very difficult to be employed in complex and changing environments owing to...The previous studies mainly focused on improving microwave absorbing(MA)performances of MA materials.Even so,these designed MA materials were very difficult to be employed in complex and changing environments owing to their single-functionalities.Herein,a combined Prussian blue analogues derived and catalytical chemical vapor deposition strategy was proposed to produce hierarchical cubic sea urchin-like yolk–shell CoNi@Ndoped carbon(NC)-CoNi@carbon nanotubes(CNTs)mixed-dimensional multicomponent nanocomposites(MCNCs),which were composed of zerodimensional CoNi nanoparticles,three-dimensional NC nanocubes and onedimensional CNTs.Because of good impedance matching and attenuation characteristics,the designed CoNi@NC-CoNi@CNTs mixed-dimensional MCNCs exhibited excellent MA performances,which achieved a minimum reflection loss(RL_(min))of−71.70 dB at 2.78 mm and Radar Cross section value of−53.23 dB m^(2).More importantly,the acquired results demonstrated that CoNi@NC-CoNi@CNTs MCNCs presented excellent photothermal,antimicrobial and anti-corrosion properties owing to their hierarchical cubic sea urchin-like yolk–shell structure,highlighting their potential multifunctional applications.It could be seen that this finding not only presented a generalizable route to produce hierarchical cubic sea urchin-like yolk–shell magnetic NC-CNTs-based mixed-dimensional MCNCs,but also provided an effective strategy to develop multifunctional MCNCs and improve their environmental adaptabilities.展开更多
The objective of this study was to identify and synthesize functional groups for the efficient adsorption of volatile organic compounds(VOCs)through a combination of theoretical calculations,molecular design,and exper...The objective of this study was to identify and synthesize functional groups for the efficient adsorption of volatile organic compounds(VOCs)through a combination of theoretical calculations,molecular design,and experimental validation.The density functional theory(DFT)calculation,focusing on the P-containing functional groups,showed that methanol adsorption was dominated by the electrostatic interaction between the carbon surface and methanol,while toluene was mainly trapped through π-π dispersive interaction between toluene molecule and functional group structure.The experimental results showed the phosphorus-doped carbon materials(PCAC)prepared by directly activating potassium phytate had a phosphorus content of up to 4.5%(atom),mainly in the form of C-O-P(O)(OH)_(2).The material exhibited a high specific area(987.6m^(2)·g^(-1))and a large adsorption capacity for methanol(440.0 mg·g^(-1))and toluene(350.1 mg·g^(-1)).These properties were superior to those of the specific commercial activated carbon(CAC)sample used for comparison in this study.The adsorption efficiencies per unit specific surface area of PCAC were 0.45 mg·g^(-1) m^(-2) for methanol and 0.35 mg·g^(-1)·m^(-2) for toluene.This study provided a novel theoretical and experimental framework for the molecular design of polarized elements to enhance the adsorption of polar gases,offering significant advancements over existing commercial solutions.展开更多
In the past century,industrial and economic growth relied heavily on fossil fuels such as coal,oil,and natural gas.As the society energy demands continue to grow,these fossil fuel reserves are depleted,leading to sign...In the past century,industrial and economic growth relied heavily on fossil fuels such as coal,oil,and natural gas.As the society energy demands continue to grow,these fossil fuel reserves are depleted,leading to significant environmental issues[1].Currently,sustainable biomass resources have attracted much attention as potential substitutes to fossil fuels for producing biofuels and commodity chemicals[2].展开更多
Pt-based materials are the benchmarked catalysts in the cathodic hydrogen evolution reaction(HER)of water splitting;the prohibitive cost and scarcity of Pt immensely impede the commercialization of hydrogen energy.Ru ...Pt-based materials are the benchmarked catalysts in the cathodic hydrogen evolution reaction(HER)of water splitting;the prohibitive cost and scarcity of Pt immensely impede the commercialization of hydrogen energy.Ru has aroused significant concern because of its Pt-like activity and much lower price.However,it’s still a top priority to minimize the Ru loading and pursue the most superior cost performance.展开更多
NaTi_(2)(PO_(4))_(3)(NTP)is a material with a NASICON structure,a three-dimensional open type skeleton,and suitable negative voltage window,which is widely regarded as a magnetic anode material for aqueous sodium ion ...NaTi_(2)(PO_(4))_(3)(NTP)is a material with a NASICON structure,a three-dimensional open type skeleton,and suitable negative voltage window,which is widely regarded as a magnetic anode material for aqueous sodium ion batteries(ASIBs).However,NTP’s in-trinsically poor conductivity hampers their use in ASIBs.Herein,bimetallic doped carbon material was designed and combined with the sol-gel method to prepare NaTi_(2)(PO_(4))_(3)-C-FeNi(NTP-C-FeNi)composite materials.This bimetallic doped carbon composite NTP ma-terial not only has a large specific surface area,but also effectively improves conductivity and promotes rapid migration of Na^(+).Follow-ing the rate performance test,NTP-C-FeNi retained a reversible capacity of 116.75 mAh·g^(-1) at 0.1 A·g^(-1),representing 95.9%of the first cycle capacity.After 500 cycles at 1.5 A·g^(-1),the cycle fixity was 85.3%.The enhancement of electrochemical performance may owe to the widening of pathways and acceleration of Na^(+)insertion/extraction facilitated by FeNi-C doping,while the carbon coating effectively promotes electrode charge transfer.The results indicate that the bimetallic doped carbon composite NaTi_(2)(PO_(4))_(3) holds potential for prac-tical applications in novel aqueous sodium ion battery systems.展开更多
The effect of carbon addition on the microstructures of TiAl-based alloy（Ti-45Al-3Fe-2Mo） was studied.The proportion of β/B2 phase reduces with the content of carbon increasing,while the colony size increases.With ...The effect of carbon addition on the microstructures of TiAl-based alloy（Ti-45Al-3Fe-2Mo） was studied.The proportion of β/B2 phase reduces with the content of carbon increasing,while the colony size increases.With increasing the carbon content,the lamellar spacing first decreases from 267 nm（Ti-45Al-3Fe-2Mo） to 237 nm（Ti-45Al-3Fe-2Mo-0.3C） and 155 nm（Ti-45Al-3Fe-2Mo-0.5C）,but then increases to 230 nm（Ti-45Al-3Fe-2Mo-1.0C） with further increase in C level,which is affected by the inhibition of carbon atom and precipitation of carbides at the lamellar interface.Precipitation of carbides shows a response to aging time at 800 ℃.P-type carbides grow up at the boundaries and near the dislocation areas with the prolonging of aging time.And these carbides are projected different morphology in different beam directions（BD）.The effects of these microstructural modifications were examined and the observations were discussed.展开更多
A carbon‐doped TiO2/fly ash support(C‐TiO2/FAS)composite photocatalyst was successfully synthesized through sol impregnation and subsequent carbonization.The carbon dopants were derived from the organic species gene...A carbon‐doped TiO2/fly ash support(C‐TiO2/FAS)composite photocatalyst was successfully synthesized through sol impregnation and subsequent carbonization.The carbon dopants were derived from the organic species generated during the synthesis of the C‐TiO2/FAS composite.A series of analytical techniques,such as scanning electron microscopy(SEM),attenuated total reflection‐Fourier transform infrared(ATR‐FTIR)spectroscopy,X‐ray photoelectron spectroscopy(XPS),and ultraviolet‐visible diffuse reflectance spectroscopy(UV‐Vis DRS),were used to characterize the properties of the prepared samples.The results indicated that C‐TiO2 was successfully coated on the FAS surface.Coupling between C‐TiO2 and FAS resulted in the formation of Si–O–C and Al–O–Ti bonds at their interface.The formation of Si–O–C and Al–O–Ti bonds gave rise to a positive shift of the valence band edge of C‐TiO2 and enhanced its oxidation capability of photogenerated holes as well as photodegradation efficiency of methyl orange.Moreover,the C‐TiO2/FAS photocatalyst exhibited favorable reusability and separability.This work may provide a new route for tuning the electronic band structure of TiO2.展开更多
Phase decomposition kinetics and the corresponding mechanical properties of the severe cold-rolled(SCRed) carbon-doped(1.3 at.%) equimolar FeCoCrNiMn high-entropy alloy(HEA) after being annealed at 500 ℃ were investi...Phase decomposition kinetics and the corresponding mechanical properties of the severe cold-rolled(SCRed) carbon-doped(1.3 at.%) equimolar FeCoCrNiMn high-entropy alloy(HEA) after being annealed at 500 ℃ were investigated. This single face-centered cubic(FCC) solid-solution HEA decomposed to M23 C6+L10, B2, and σ in chronological order. The formation kinetics of the L10, B2, and σ phases followed the Johnson-Mehl-AvramiKolmogorov(JMAK) equation. The yield strength of the HEA was 1520 MPa and increased to 1920 MPa after being annealed at 500 ℃ for 1 h, as a result of the formation of nanosized M23 C6 and L10. Both strength and ductility decreased after 2 d of annealing due to the increase of volume fractions and the coarsening of the M23C6 and L10 precipitates. From 4 to 32 d, the hardness was found to increase, which is ascribed to the rapid formation of the B2 and σ phases. From 32 to 64 d, the hardness increased further to finally reach about HV 760, with the FCC matrix almost exhausted to form the M23 C6, L10, B2, and σ phases. The results of this work may serve as a guide for the heat-treatment of carbon-doped HEAs.展开更多
Noble metals, such as platinum, ruthenium and iridium‐group metals, are often used as oxygen reduction or evolution reaction （ORR/OER） electrocatalysts. To reduce the cost and provide an application of bifunctional...Noble metals, such as platinum, ruthenium and iridium‐group metals, are often used as oxygen reduction or evolution reaction （ORR/OER） electrocatalysts. To reduce the cost and provide an application of bifunctional catalysis, in this work, cobalt oxide supported on nitrogen and phospho‐rus co‐doped carbon （Co3O4/NPC） was fabricated and examined as a bifunctional electrocatalyst for OER and ORR. To prepare Co3O4/NPC, NPC was pyrolyzed from melamine and phytic acid support‐ed on carbon, followed by the solvothermal synthesis of Co3O4 on NPC. Linear sweep voltammetry was used to evaluate the activity for OER and ORR. For OER, Co3O4/NPC showed an onset potential of 0.54 V （versus the saturated calomel electrode） and a current density of 21.95 mA/cm2 at 0.80 V, which was better than both Co3O4/C and NPC. The high activity of Co3O4/NPC was attributed to a synergistic effect of the N, P co‐dopants and Co3O4. For ORR, Co3O4/NPC exhibited an activity close to commercial Pt/C in terms of the diffusion limited current density （–4.49 vs–4.76 mA/cm2 at–0.80 V）, and Co3O4 played the key role for the catalysis. Chronoamperometry （current versus time） was used to evaluate the stability, which showed that Co3O4/NPC maintained 46%current after the chronoamperometry test for OER and 95% current for ORR. Overall, Co3O4/NPC exhibited high activity and improved stability for both OER and ORR.展开更多
Commercial production of vinyl chloride from acetylene relies on the use of HgCla as the catalyst, which has caused severe environmental problem and threats to human health because of its toxicity. Therefore, it is vi...Commercial production of vinyl chloride from acetylene relies on the use of HgCla as the catalyst, which has caused severe environmental problem and threats to human health because of its toxicity. Therefore, it is vital to explore alternative catalysts without mercury. We report here that N-doped carbon can catalyze directly transformation of acetylene to vinyl chloride. Particularly, N-doped high surface area mesoporous carbon exhibits a rather high activity with the acetylene conversion reaching 77% and vinyl chloride selectivity above 98% at a space velocity of 1.0 mL.min-l.g-1 and 200 ~C. It delivers a stable performa℃nce within a test period of 100h and no obvious deactivation is observed, demonstrating potentials to substitute the notoriously toxic mercuric chloride catalyst.展开更多
Alloy-type materials with the characteristics of high theoretical capacity,low sodiation/desodiation potential,and good conductivity are considered as one of the most promising anodes for sodium-ion batteries or capac...Alloy-type materials with the characteristics of high theoretical capacity,low sodiation/desodiation potential,and good conductivity are considered as one of the most promising anodes for sodium-ion batteries or capacitors.However,the large volume change during the sodiation leads to poor cyclability and slow kinetics,thus presenting the main issue impeding the practical application.Herein,we propose a facile wet chemistry and pyrolysis method to synthesize Sb-carbon composite that Sb nanoparticles or single atoms are confined and/or dispersed in the wrinkled carbon framework with high nitrogen content.This unique architecture of Sb-carbon composite increases atomic interface contact/interaction with Na~+,facilitating ion diffusion and alleviating the volume change of Sb during the charge/discharge process.Half-cell test shows that Sb-carbon composite exhibits a high-rate capability and stable cycling life.Furthermore,sodium-ion capacitors fabricated by employing Sb-carbon composite as anode and home-made active carbon as cathode,deliver both high-energy density of 157 Wh·kg^(-1)and high-power density of 25 kW·kg^(-1)as well as excellent cycling performance exceeding 4000 cycles.展开更多
Biomass derived porous nanostructured nitrogen doped carbon(PNC) has been extensively investigated as the electrode material for electrochemical catalytic reactions and rechargeable batteries. Biomass with and without...Biomass derived porous nanostructured nitrogen doped carbon(PNC) has been extensively investigated as the electrode material for electrochemical catalytic reactions and rechargeable batteries. Biomass with and without containing nitrogen could be designed and optimized to prepare PNC via hydrothermal carbonization, pyrolysis, and other methods. The presence of nitrogen in carbon can provide more active sites for ion absorption, improve the electronic conductivity, increase the bonding between carbon and sulfur, and enhance the electrochemical catalytic reaction. The synthetic methods of natural biomass derived PNC, heteroatomic co-or tri-doping into biomass derived carbon and the application of biomass derived PNC in rechargeable Li/Na batteries, high energy density Li-S batteries, supercapacitors, metal-air batteries and electrochemical catalytic reaction(oxygen reduction and evolution reactions, hydrogen evolution reaction) are summarized and discussed in this review. Biomass derived PNCs deliver high performance electrochemical storage properties for rechargeable batteries/supercapacitors and superior electrochemical catalytic performance toward hydrogen evolution, oxygen reduction and evolution, as promising electrodes for electrochemical devices including battery technologies, fuel cell and electrolyzer.展开更多
基金This work was financially supported by the National Natural Science Foundation of China (52122308,21905253,51973200)the Natural Science Foundation of Henan (202300410372).
文摘The defect-free structure of Mo-based materials is a“double-edged sword”,which endows the material with excellent stability,but limits its chemical versatility and application in electrochemical hydrogen evolution reaction(HER).Carbon doping engineering is an attractive strategy to effectively improve the performance of Mo-based catalyst and maintain their stability.Herein,we report a cross-linked porous carbon-doped MoO_(2)(C–MoO_(2))-based catalyst Ru/C–MoO_(2) for electrochemical HER,which is prepared by the convenient redox solid-phase reaction(SPR)of porous RuO_(2)/Mo_(2)C composite precursor.Theoretical studies reveal that due to the presence of carbon atoms,the electronic structure of C–MoO_(2) has been properly adjusted,and the loaded small Ru nanoparticles provide a fast water dissociation rate and moderate H adsorption strength.In electrochemical studies under a pH-universal environment,Ru/C–MoO_(2) electrocatalyst exhibits a low overpotential at a current density of 10 mA cm^(-2) and has a low Tafel slope.Meanwhile,Ru/C-MoO_(2) has excellent stability for more than 100 h at an initial current density of 100 mA cm^(-2).
基金A Grant-in-Aid for the COE project (Giant Molecules and Complex Systems), a Grant-in-Aid for Science Research (No.14750660) by Ministry of Education, Culture, Sports, Science and Technology, Japan, the JFE 21st Century Foundation and the Steel Industry for the Advancement of Environmental Protection Technology Foundation, Japan
文摘Nitrogen and/or carbon doped titania photocatalysts were prepared by a novel mechanochemical method. The prepared powders possessed two absorption edges around 400 and 540 nm wavelengths and showed excellent photocatalytic ability for nitrogen monoxide oxidation under visible light irradiation. Under the irradiation of visible light of wavelength >510 nm,37% of nitrogen monoxide could be continuously removed by the carbon and nitrogen co-doped titania prepared by planetary ball milling of P-25 titania–10% hexamethylenetetramine mixture followed by calcination in air at 400-C.
基金supported by the National Natural Science Foundation of China(U1663225,21805280)Program for Changjiang Scholars and Innovative Research Team in University(IRT15R52)+2 种基金the Minstry of Education of Chinathe 111 Project(Grant No.B20002)from the Ministry of Science and Technology and the Ministry of Education of China,China,European Commission,Interreg V France-Wallonie-Vlaanderen(Depollutair)the Fundamental Research Funds for the Central Universities(WUT:2017III001),Chinathe FJIRSM&IUE Joint Research Fund(RHZX-2018-002),China for supporting this work。
文摘The"one pot"simultaneous carbon coating and doping of TiO_(2) materials by the hydrolysis of TiCl4 in fructose is reported.The synergistic effect of carbon doping and coating of TiO_(2) to significantly boost textural,optical and electronic properties and photocurrent of TiO_(2) for high performance visible light H2 production from water splitting has been comprehensively investigated.Carbon doping can significantly increase the thermal stability,thus inhibiting the phase transformation of the Titania material from anatase to rutile while carbon coating can suppress the grain aggregation of TiO_(2).The synergy of carbon doping and coating can not only ensure an enhanced narrowing effect of the electronic band gap of TiO_(2) thus extending the absorption of photocatalysts to the visible regions,but also promote dramatically the separation of electron-hole pairs.Owing to these synergistic effects,the carbon coated and doped TiO_(2) shows much superior photocatalytic activity for both degradation of organics and photocatalytic/photoelectro chemical(PEC)water splitting under simulated sunlight illumination.The photocatalytic activity of obtained materials can reach 5,4 and 2 times higher than that of pristine TiO_(2),carbon doped TiO_(2) and carbon coated TiO_(2),respectively in the degradation of organic pollutants.The carbon coated and doped TiO_(2) materials exhibited more than 37 times and hundreds of times photocurrent enhancement under simulated sunlight and visible light,respectively compared to that of pristine TiO_(2).The present work providing new comprehensive understanding on carbon coating and doping effect could be very helpful for the development of advanced TiO_(2) materials for a large series of applications.
基金the National Natural Science Foundation of China(Grant No.11704317)the Xiamen University Malaysia Research Fund(Grant No.XMUMRF/2019-C3/IORI/0001).
文摘The magnetic and electronic properties of strontium titanate with different carbon dopant configurations are explored using first-principles calculations with a generalized gradient approximation(GGA)and the GGA+U approach.Our results show that the structural stability,electronic properties and magnetic properties of C-doped SrTiO3 strongly depend on the distance between carbon dopants.In both GGA and GGA+U calculations,the doping structure is mostly stable with a nonmagnetic feature when the carbon dopants are nearest neighbors,which can be ascribed to the formation of a C–C dimer pair accompanied by stronger C–C and weaker C–Ti hybridizations as the C–C distance becomes smaller.As the C–C distance increases,C-doped SrTiO3 changes from an n-type nonmagnetic metal to ferromagnetic/antiferromagnetic half-metal and to an antiferromagnetic/ferromagnetic semiconductor in GGA calculations,while it changes from a nonmagnetic semiconductor to ferromagnetic half-metal and to an antiferromagnetic semiconductor using the GGA+U method.Our work demonstrates the possibility of tailoring the magnetic and electronic properties of C-doped SrTiO3,which might provide some guidance to extend the applications of strontium titanate as a magnetic or optoelectronic material.
文摘Efficacious regulation of the geometric and electronic structures of carbon nanomaterials via the introduction of defects and their synergy is essential to achieving good electrochemical performance.However,the guidelines for designing hybrid materials with advantageous structures and the fundamental understanding of their electrocatalytic mechanisms remain unclear.Herein,superfine Pt and PtCu nanoparticles supported by novel S,N‐co‐doped multi‐walled CNT(MWCNTs)were prepared through the innovative pyrolysis of a poly(3,4‐ethylenedioxythiophene)/polyaniline copolymer as a source of S and N.The uniform wrapping of the copolymer around the MWCNTs provides a high density of evenly distributed defects on the surface after the pyrolysis treatment,facilitating the uniform distribution of ultrafine Pt and PtCu nanoparticles.Remarkably,the Pt_(1)Cu_(2)/SN‐MWCNTs show an obviously larger electroactive surface area and higher mass activity,stability,and CO poisoning resistance in methanol oxidation compared to Pt/SN‐MWCNTs,Pt/S‐MWCNTs,Pt/N‐MWCNTs,and commercial Pt/C.Density functional theory studies confirm that the co‐doping of S and N considerably deforms the CNTs and polarizes the adjacent C atoms.Consequently,both the adsorption of Pt1Cu2 onto the SN‐MWCNTs and the subsequent adsorption of methanol are enhanced;in addition,the catalytic activity of Pt_(1)Cu_(2)/SN‐MWCNTs for methanol oxidation is thermodynamically and kinetically more favorable than that of its CNT and N‐CNT counterparts.This work provides a novel method to fabricate high‐performance fuel cell electrocatalysts with highly dispersed and stable Pt‐based nanoparticles on a carbon substrate.
基金Funded by the National Natural Science Foundation of China(No.51604087)the Science and Technology Program of Guangdong Province of China(No.2016A010104019)the Science and Technology Program of Guangzhou City of China(No.201607010001)
文摘Alpha nickel hydroxide has better performances than commercial beta nickel hydroxide. However, the main defect is that α-phase is difficult to synthesize and easily transformed to β-phase Ni（OH）2 upon aging in a strong alkaline solution. In this study, the Al-Co, Al-Yb, Yb-Co and Al-Yb-Co multiple doping was used respectively. By controlling the amount of sodium carbonate, the α-Ni（OH）2 was prepared by ultrasonic-assisted precipitation. And the influence of sodium carbonate on the crystalline phase and structure stability for alpha nickel hydroxide was studied. The results demonstrate that, with increasing amount, the biphase nickel hydroxide transforms to pure alpha nickel hydroxide gradually, and the structure stability is also improved. When the amount of sodium carbonate is 2 g, the sample still keeps α-Ni（OH）2 after being aged for 30 days, for Al-Yb-Co-Ni（OH）2. And when the amount is less than 2 g, the phase transformations exist in the samples with different extents. These results demonstrated that the amount of sodium carbonate is a critical factor to maintain the structural stability of α-Ni（OH）2.
基金supported by the National Natural Science Foundation of China (Grant No.22063010)the Natural Science Foundation of Shaanxi Province (Grant No.2022QFY07-05)Yan'an Science and Technology Plan Project (Grants No.2022SLJBZ-002, 2023-CYL-193)。
文摘We used the natural product chamomile as a carbon source to synthesize praseodymium(Pr) and nitrogen(N) co-doped biomass carbon dots(Pr/N-BCDs) with remarkable luminescence properties by one-step hydrothermal method.Compared with single N-doped BCDs(N-BCDs) and Pr-doped BCDs(Pr-BCDs),Pr/N-BCDs not only showed better fluorescence properties and stability but also achieved a significant increase in quantum yield of 12%.More importantly,under certain conditions,Pr/N-BCDs and 2,4-dinitrophenylhydrazide(2,4-DNPH) had significant fluorescence internal filtration effect(IFE) and dynamic quenching effect,and in the concentration range of0.50-20 μmol·L^(-1),the concentration of 2,4-DNPH had a good linear relationship with the fluorescence quenching signal,and the detection limit was as low as 2.1 nmol·L^(-1).
基金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The novel fabrication of multiple components and unique heterostructure can inject infinite vitality into the electromagnetic wave(EMW)attenuation field.Herein,through the self-assembly of polyimide com-plexes and catalytic chemical vapor deposition,porous carbon microflowers were synthesized accompa-nied by carbon nanotubes(CNTs).By regulating the metal ions,the composition and structure of the as-obtained hybrids are modified correspondingly,and thus the adjustable thermal management and EMW absorption capabilities are obtained.In detail,the rich pores and huge specific surface area endow the hierarchical structures with distinguished thermal insulation ability(λ<0.07).The carbon framework and CNTs are beneficial for consuming EMWs via conductive loss and defect polarization loss while reduc-ing the filling ratio and thickness.The doped heteroatoms and abundant heterointerfaces generate ample dipole polarization and interface polarization losses(supported by DFT calculation).The metal nanopar-ticles uniformly embedded in the carbon framework offer optimized impedance matching,proper de-fect polarization,and suitable magnetic loss.Accordingly,the synergy of magnetic-dielectric balance and flower-like superstructure enables FNCFN2 and NNCFN2 to accomplish remarkable microwave absorbing capacity with thin thickness(14 wt.%).Therefore,respectable specific reflection loss and specific effec-tive absorption bandwidth are acquired(215.39 dB mm^(-1) and 22.10 GHz mm^(-1),257.23 dB mm^(-1) and 22.12 GHz mm^(-1) respectively),superior to those of certain renowned carbon-based absorbers.The simu-lation results of electric field intensity distributions,power loss density,and radar cross section reduction(maximum value of 36.02 dBm2)also verify the prominent radar stealth capability.Moreover,the cus-tomizable approach can be applied to other metals to obtain fulfilling behaviors.Henceforth,this work provides profound insights into the relationship between structure and performance,and proposes an efficient path for mass-producing multifunctional and high-performance EMW absorbers with excellent thermal properties.
基金support from the National Natural Science Foundation of China(U21A2093)Shaanxi Province Key Research and Development Plan Project(2023-YBGY-461)+4 种基金Platform of Science and Technology and Talent Team Plan of Guizhou province(GCC[2023]007)Guizhou Provincial Basic Research Program(Natural Science)(No.ZK[2025]Key 086)Fok Ying Tung Education Foundation(171095)financial support,Innovation Capability Support Program of Shaanxi(2024RS-CXTD-57)Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University(CX2024094)。
文摘The previous studies mainly focused on improving microwave absorbing(MA)performances of MA materials.Even so,these designed MA materials were very difficult to be employed in complex and changing environments owing to their single-functionalities.Herein,a combined Prussian blue analogues derived and catalytical chemical vapor deposition strategy was proposed to produce hierarchical cubic sea urchin-like yolk–shell CoNi@Ndoped carbon(NC)-CoNi@carbon nanotubes(CNTs)mixed-dimensional multicomponent nanocomposites(MCNCs),which were composed of zerodimensional CoNi nanoparticles,three-dimensional NC nanocubes and onedimensional CNTs.Because of good impedance matching and attenuation characteristics,the designed CoNi@NC-CoNi@CNTs mixed-dimensional MCNCs exhibited excellent MA performances,which achieved a minimum reflection loss(RL_(min))of−71.70 dB at 2.78 mm and Radar Cross section value of−53.23 dB m^(2).More importantly,the acquired results demonstrated that CoNi@NC-CoNi@CNTs MCNCs presented excellent photothermal,antimicrobial and anti-corrosion properties owing to their hierarchical cubic sea urchin-like yolk–shell structure,highlighting their potential multifunctional applications.It could be seen that this finding not only presented a generalizable route to produce hierarchical cubic sea urchin-like yolk–shell magnetic NC-CNTs-based mixed-dimensional MCNCs,but also provided an effective strategy to develop multifunctional MCNCs and improve their environmental adaptabilities.
基金supported by the Open Project of Xiangjiang Laboratory (22XJ03026)the National Natural Science Foundation of China (72004060)+3 种基金the Provincial Natural Science Foundation of Hunan Province (2022JJ30015)the Scientific Research Project of Hunan Education Department, China (23A0457)Environmental Protection Scientific Research Project of Hunan Province (HBKT2021021)the “Digital-intelligence+” interdisciplinary research project of Hunan University of Technology and Business (2023SZJ22)
文摘The objective of this study was to identify and synthesize functional groups for the efficient adsorption of volatile organic compounds(VOCs)through a combination of theoretical calculations,molecular design,and experimental validation.The density functional theory(DFT)calculation,focusing on the P-containing functional groups,showed that methanol adsorption was dominated by the electrostatic interaction between the carbon surface and methanol,while toluene was mainly trapped through π-π dispersive interaction between toluene molecule and functional group structure.The experimental results showed the phosphorus-doped carbon materials(PCAC)prepared by directly activating potassium phytate had a phosphorus content of up to 4.5%(atom),mainly in the form of C-O-P(O)(OH)_(2).The material exhibited a high specific area(987.6m^(2)·g^(-1))and a large adsorption capacity for methanol(440.0 mg·g^(-1))and toluene(350.1 mg·g^(-1)).These properties were superior to those of the specific commercial activated carbon(CAC)sample used for comparison in this study.The adsorption efficiencies per unit specific surface area of PCAC were 0.45 mg·g^(-1) m^(-2) for methanol and 0.35 mg·g^(-1)·m^(-2) for toluene.This study provided a novel theoretical and experimental framework for the molecular design of polarized elements to enhance the adsorption of polar gases,offering significant advancements over existing commercial solutions.
基金funded by the Master,PhD Scholarship Programme of Vingroup Innovation Foundation(VINIF),code VINIF.2024.TS.035funded by Vietnam National University,Ho Chi Minh City(VNUHCM)under grant number NCM2024-18-01。
文摘In the past century,industrial and economic growth relied heavily on fossil fuels such as coal,oil,and natural gas.As the society energy demands continue to grow,these fossil fuel reserves are depleted,leading to significant environmental issues[1].Currently,sustainable biomass resources have attracted much attention as potential substitutes to fossil fuels for producing biofuels and commodity chemicals[2].
基金supported by the Development Project of Youth Innovation Team in Shandong Colleges and Universities(No.2019KJC031)the Natural Science Foundation of Shandong Province(Nos.ZR2019MB064,ZR2021MB122 and ZR2022MB137)the Doctoral Program of Liaocheng University(No.318051608).
文摘Pt-based materials are the benchmarked catalysts in the cathodic hydrogen evolution reaction(HER)of water splitting;the prohibitive cost and scarcity of Pt immensely impede the commercialization of hydrogen energy.Ru has aroused significant concern because of its Pt-like activity and much lower price.However,it’s still a top priority to minimize the Ru loading and pursue the most superior cost performance.
基金supported by the National Natural Science Foundation of China(Nos.52072298 and 51802261)the Scientific Research Program Funded by Shaanxi Provincial Education Department,China(No.23JK0662)+1 种基金the Natural Science Foundation of Shaanxi Province,China(Nos.2023-JC-YB-515 and 2025JC-YBQN-758)the Youth Innovation Team of Shaanxi Universities.
文摘NaTi_(2)(PO_(4))_(3)(NTP)is a material with a NASICON structure,a three-dimensional open type skeleton,and suitable negative voltage window,which is widely regarded as a magnetic anode material for aqueous sodium ion batteries(ASIBs).However,NTP’s in-trinsically poor conductivity hampers their use in ASIBs.Herein,bimetallic doped carbon material was designed and combined with the sol-gel method to prepare NaTi_(2)(PO_(4))_(3)-C-FeNi(NTP-C-FeNi)composite materials.This bimetallic doped carbon composite NTP ma-terial not only has a large specific surface area,but also effectively improves conductivity and promotes rapid migration of Na^(+).Follow-ing the rate performance test,NTP-C-FeNi retained a reversible capacity of 116.75 mAh·g^(-1) at 0.1 A·g^(-1),representing 95.9%of the first cycle capacity.After 500 cycles at 1.5 A·g^(-1),the cycle fixity was 85.3%.The enhancement of electrochemical performance may owe to the widening of pathways and acceleration of Na^(+)insertion/extraction facilitated by FeNi-C doping,while the carbon coating effectively promotes electrode charge transfer.The results indicate that the bimetallic doped carbon composite NaTi_(2)(PO_(4))_(3) holds potential for prac-tical applications in novel aqueous sodium ion battery systems.
基金Project (2011CB605505) supported by the National Basic Research Program of China
文摘The effect of carbon addition on the microstructures of TiAl-based alloy（Ti-45Al-3Fe-2Mo） was studied.The proportion of β/B2 phase reduces with the content of carbon increasing,while the colony size increases.With increasing the carbon content,the lamellar spacing first decreases from 267 nm（Ti-45Al-3Fe-2Mo） to 237 nm（Ti-45Al-3Fe-2Mo-0.3C） and 155 nm（Ti-45Al-3Fe-2Mo-0.5C）,but then increases to 230 nm（Ti-45Al-3Fe-2Mo-1.0C） with further increase in C level,which is affected by the inhibition of carbon atom and precipitation of carbides at the lamellar interface.Precipitation of carbides shows a response to aging time at 800 ℃.P-type carbides grow up at the boundaries and near the dislocation areas with the prolonging of aging time.And these carbides are projected different morphology in different beam directions（BD）.The effects of these microstructural modifications were examined and the observations were discussed.
文摘A carbon‐doped TiO2/fly ash support(C‐TiO2/FAS)composite photocatalyst was successfully synthesized through sol impregnation and subsequent carbonization.The carbon dopants were derived from the organic species generated during the synthesis of the C‐TiO2/FAS composite.A series of analytical techniques,such as scanning electron microscopy(SEM),attenuated total reflection‐Fourier transform infrared(ATR‐FTIR)spectroscopy,X‐ray photoelectron spectroscopy(XPS),and ultraviolet‐visible diffuse reflectance spectroscopy(UV‐Vis DRS),were used to characterize the properties of the prepared samples.The results indicated that C‐TiO2 was successfully coated on the FAS surface.Coupling between C‐TiO2 and FAS resulted in the formation of Si–O–C and Al–O–Ti bonds at their interface.The formation of Si–O–C and Al–O–Ti bonds gave rise to a positive shift of the valence band edge of C‐TiO2 and enhanced its oxidation capability of photogenerated holes as well as photodegradation efficiency of methyl orange.Moreover,the C‐TiO2/FAS photocatalyst exhibited favorable reusability and separability.This work may provide a new route for tuning the electronic band structure of TiO2.
基金Project(51901134)supported by the National Natural Science Foundation of ChinaProject(SJTU.18X100040023)supported by the Program of Scientific Research Ability Cultivation for Young Researchers,China。
文摘Phase decomposition kinetics and the corresponding mechanical properties of the severe cold-rolled(SCRed) carbon-doped(1.3 at.%) equimolar FeCoCrNiMn high-entropy alloy(HEA) after being annealed at 500 ℃ were investigated. This single face-centered cubic(FCC) solid-solution HEA decomposed to M23 C6+L10, B2, and σ in chronological order. The formation kinetics of the L10, B2, and σ phases followed the Johnson-Mehl-AvramiKolmogorov(JMAK) equation. The yield strength of the HEA was 1520 MPa and increased to 1920 MPa after being annealed at 500 ℃ for 1 h, as a result of the formation of nanosized M23 C6 and L10. Both strength and ductility decreased after 2 d of annealing due to the increase of volume fractions and the coarsening of the M23C6 and L10 precipitates. From 4 to 32 d, the hardness was found to increase, which is ascribed to the rapid formation of the B2 and σ phases. From 32 to 64 d, the hardness increased further to finally reach about HV 760, with the FCC matrix almost exhausted to form the M23 C6, L10, B2, and σ phases. The results of this work may serve as a guide for the heat-treatment of carbon-doped HEAs.
基金supported by the National Natural Science Foundation of China (21375016,20475022 and 21505019)~~
文摘Noble metals, such as platinum, ruthenium and iridium‐group metals, are often used as oxygen reduction or evolution reaction （ORR/OER） electrocatalysts. To reduce the cost and provide an application of bifunctional catalysis, in this work, cobalt oxide supported on nitrogen and phospho‐rus co‐doped carbon （Co3O4/NPC） was fabricated and examined as a bifunctional electrocatalyst for OER and ORR. To prepare Co3O4/NPC, NPC was pyrolyzed from melamine and phytic acid support‐ed on carbon, followed by the solvothermal synthesis of Co3O4 on NPC. Linear sweep voltammetry was used to evaluate the activity for OER and ORR. For OER, Co3O4/NPC showed an onset potential of 0.54 V （versus the saturated calomel electrode） and a current density of 21.95 mA/cm2 at 0.80 V, which was better than both Co3O4/C and NPC. The high activity of Co3O4/NPC was attributed to a synergistic effect of the N, P co‐dopants and Co3O4. For ORR, Co3O4/NPC exhibited an activity close to commercial Pt/C in terms of the diffusion limited current density （–4.49 vs–4.76 mA/cm2 at–0.80 V）, and Co3O4 played the key role for the catalysis. Chronoamperometry （current versus time） was used to evaluate the stability, which showed that Co3O4/NPC maintained 46%current after the chronoamperometry test for OER and 95% current for ORR. Overall, Co3O4/NPC exhibited high activity and improved stability for both OER and ORR.
基金supported by the Natural Science Foundation of China(No.11079005 and 21033009)the Ministry of Science and Technology of China(2011CBA00503 and 2012CB720302)
文摘Commercial production of vinyl chloride from acetylene relies on the use of HgCla as the catalyst, which has caused severe environmental problem and threats to human health because of its toxicity. Therefore, it is vital to explore alternative catalysts without mercury. We report here that N-doped carbon can catalyze directly transformation of acetylene to vinyl chloride. Particularly, N-doped high surface area mesoporous carbon exhibits a rather high activity with the acetylene conversion reaching 77% and vinyl chloride selectivity above 98% at a space velocity of 1.0 mL.min-l.g-1 and 200 ~C. It delivers a stable performa℃nce within a test period of 100h and no obvious deactivation is observed, demonstrating potentials to substitute the notoriously toxic mercuric chloride catalyst.
基金financially supported by the National Natural Science Foundation of China(No.51902188)the Natural Science Foundation of Jiangsu Province(No.BK20190207)+2 种基金the Natural Science Foundation of Shandong Province(Nos.ZR2020KE034 and ZR2021ME105)the Natural Science Doctoral Foundation of Shandong Province(No.ZR2019BEM019)the Future Program for Young Scholar of Shandong University。
文摘Alloy-type materials with the characteristics of high theoretical capacity,low sodiation/desodiation potential,and good conductivity are considered as one of the most promising anodes for sodium-ion batteries or capacitors.However,the large volume change during the sodiation leads to poor cyclability and slow kinetics,thus presenting the main issue impeding the practical application.Herein,we propose a facile wet chemistry and pyrolysis method to synthesize Sb-carbon composite that Sb nanoparticles or single atoms are confined and/or dispersed in the wrinkled carbon framework with high nitrogen content.This unique architecture of Sb-carbon composite increases atomic interface contact/interaction with Na~+,facilitating ion diffusion and alleviating the volume change of Sb during the charge/discharge process.Half-cell test shows that Sb-carbon composite exhibits a high-rate capability and stable cycling life.Furthermore,sodium-ion capacitors fabricated by employing Sb-carbon composite as anode and home-made active carbon as cathode,deliver both high-energy density of 157 Wh·kg^(-1)and high-power density of 25 kW·kg^(-1)as well as excellent cycling performance exceeding 4000 cycles.
基金the support from the USDA National Institute of Food and Agriculture, HSI Collaboration:Integrating Food Science/Engineering and Education Network(IFSEEN,award number: 2015-3842224059)the support from the NMSU Agricultural Experiment Station Graduate Research Award
文摘Biomass derived porous nanostructured nitrogen doped carbon(PNC) has been extensively investigated as the electrode material for electrochemical catalytic reactions and rechargeable batteries. Biomass with and without containing nitrogen could be designed and optimized to prepare PNC via hydrothermal carbonization, pyrolysis, and other methods. The presence of nitrogen in carbon can provide more active sites for ion absorption, improve the electronic conductivity, increase the bonding between carbon and sulfur, and enhance the electrochemical catalytic reaction. The synthetic methods of natural biomass derived PNC, heteroatomic co-or tri-doping into biomass derived carbon and the application of biomass derived PNC in rechargeable Li/Na batteries, high energy density Li-S batteries, supercapacitors, metal-air batteries and electrochemical catalytic reaction(oxygen reduction and evolution reactions, hydrogen evolution reaction) are summarized and discussed in this review. Biomass derived PNCs deliver high performance electrochemical storage properties for rechargeable batteries/supercapacitors and superior electrochemical catalytic performance toward hydrogen evolution, oxygen reduction and evolution, as promising electrodes for electrochemical devices including battery technologies, fuel cell and electrolyzer.
