With high surface area,open porosity and high efficiency,a catalyst was prepared and firstly employed in electrocatalytic reduction of CO2 and electrosynthesis of dimethyl carbonate(DMC).The electrochemical property...With high surface area,open porosity and high efficiency,a catalyst was prepared and firstly employed in electrocatalytic reduction of CO2 and electrosynthesis of dimethyl carbonate(DMC).The electrochemical property for electrocatalytic reduction of CO2 in ionic liquid was studied by cyclic voltammogram(CV).The effects of various reaction variables like temperature,working potential and cathode materials on the electrocatalytic performance were also investigated.80%yield of DMC was obtained under the optimal reaction conditions.展开更多
Lithium-selenium(Li-Se)battery has attracted growing attention.Nevertheless,its practical application is still impeded by the shuttle effect of the formed polyselenides.Herein,we report in-situ hydrothermal weaving th...Lithium-selenium(Li-Se)battery has attracted growing attention.Nevertheless,its practical application is still impeded by the shuttle effect of the formed polyselenides.Herein,we report in-situ hydrothermal weaving the three-dimensional(3 D)highly conductive hierarchically interconnected nanoporous web by threading microporous metal organic framework MIL-68(Al)crystals onto multi-walled carbon nanotubes(MWCNTs).Such 3 D hierarchically nanoporous web(3 D MIL-68(Al)@MWCNTs web)with a very high surface area,a large amount of micropores,electrical conductivity and elasticity strongly traps the soluble polyselenides during the electrochemical reaction and significantly facilitates lithium ion diffusion and electron transportation.Molecular dynamic calculation confirmed the strong affinity of MIL-68(Al)for the adsorption of polyselenides,quite suitable for Li-Se battery.Their hexahedral channels(1.56 nm)are more efficient for the confinement of polyselenides and for the diffusion of electrolytes compared to their smaller triangular channels(0.63 nm).All these excellent characteristics of 3 D MIL-68(Al)@MWCNTs web with suitable confinement of a large amount of selenium and the conductive linkage between MIL-68(Al)host by MWCNTs result in a high capacity of 453 m Ah/g at 0.2 C with 99.5%coulombic efficiency after 200 cycles with significantly improved cycle stability and rate performance.The 3 D MIL-68(Al)@MWCNTs web presents a good performance in Li-Se battery in term of the specific capacity and cycling stability and also in terms of rate performance compared with all the metal-organic framework(MOF)based or MOF derived porous carbons used in Li-Se battery.展开更多
Rechargeable aluminum batteries(RABs),which use earth-abundant and high-volumetric-capacity metal anodes(8040 m Ah cm-3),have great potential as next-generation power sources because they use cheaper resources to deli...Rechargeable aluminum batteries(RABs),which use earth-abundant and high-volumetric-capacity metal anodes(8040 m Ah cm-3),have great potential as next-generation power sources because they use cheaper resources to deliver higher energies,compared to current lithium ion batteries.However,the mechanism of charge delivery in the newly developed,ionic liquid-based electrolytic system for RABs differs from that in conventional organic electrolytes.Thus,targeted research efforts are required to address the large overpotentials and cycling decay encountered in the ionic liquid-based electrolytic system.In this study,a nanoporous carbon(NPC)electrode with well-developed nanopores is used to develop a high-performance aluminum anode.The negatively charged nanopores can provide quenched dynamics of electrolyte molecules in the aluminum deposition process,resulting in an increased collision rate.The fast chemical equilibrium of anionic species induced by the facilitated anionic collisions leads to more favorable reduction reactions that form aluminum metals.The nanoconfinement effect causes separated nucleation and growth of aluminum nanoparticles in the multiple confined nanopores,leading to higher coulombic efficiencies and more stable cycling performance compared with macroporous carbon black and 2D stainless steel electrodes.展开更多
A new nanocomposite material for construction of glucose biosensor was prepared. The biosensor was formed by entrapping glucose oxidase(Gox) into chitosan/nanoporous ZrO2/multiwalled carbon nanotubes nanocomposite fil...A new nanocomposite material for construction of glucose biosensor was prepared. The biosensor was formed by entrapping glucose oxidase(Gox) into chitosan/nanoporous ZrO2/multiwalled carbon nanotubes nanocomposite film. In this biosensing thin film, the multiwalled carbon nanotubes can effectively catalyze hydrogen peroxide and nanoporous ZrO2 can enhance the stability of the immobilized enzyme. The resulting biosensor provides a very effective matrix for the immobilization of glucose oxidase and exhibits a wide linear response range from 8 μmol/L to 3 mmol/L with a correlation coefficient of 0.994 for the detection of glucose. And the response time and detection limit of the biosensor are determined to be 6 s and 3.5 μmol/L, respectively. Another attractive characteristic is that the biosensor is inexpensive, stable and reliable.展开更多
Nanoporous carbons were synthesized using furfuryl alcohol and sucrose as precursors and MCM-41 and mordenite as nanoporous templates.The produced nanoporous carbons were used as adsorbent for methane storage.The aver...Nanoporous carbons were synthesized using furfuryl alcohol and sucrose as precursors and MCM-41 and mordenite as nanoporous templates.The produced nanoporous carbons were used as adsorbent for methane storage.The average pore diameter of the samples varied from 3.9 nm to 5.9 nm and the BET surface area varied from 320m2/g to 824m2/g.The volumetric adsorption experiments revealed that MCM-41 and sucrose had better performance compared with mordenite and furfuryl alcohol,correspondingly.Also,the effect of precursor to template ratio on the structure of nanoporous carbons and their adsorption capacities was investigated.The nanoporous carbon produced from MCM-41 mesoporous molecular sieve partially filled by sucrose shows the best methane adsorption capacity among the tested samples.展开更多
Studies on three-dimensional structured carbon templates have focused on how to guide homogeneous lithium metal nucleation and growth for lithium metal anodes(LMAs).However,there is still insufficient evidence for a k...Studies on three-dimensional structured carbon templates have focused on how to guide homogeneous lithium metal nucleation and growth for lithium metal anodes(LMAs).However,there is still insufficient evidence for a key factor to achieve their high electrochemical performance.Here,the effects of nanopores and sulfur doping on carbon-based nanoporous host(CNH)electrode materials for LMAs were investigated using natural polymer-derived CNHs.Homogeneous pore-filling behaviors of lithium metal in the nanopores of the CNH electrode materials were first observed by ex situ scanning electron microscopy analysis,where the protective lithium metal nucleation and growth process led to significantly high Coulombic efficiency(CE)of~99.4%and stable 600 cycles.In addition,a comparison study of CNH and sulfurdoped CNH(S-CNH)electrodes,which differ only in the presence or absence of sulfur,revealed that sulfur doping can cause lower electrochemical series resistance,higher CE value,and better cycling stability in a wide range of current densities and number of cycles.Moreover,S-CNH-based LMAs showed high electrochemical performance in full-cell Li-S battery tests using a sulfur copolymer cathode,where a high energy density of 1370Wh kgelectrode−1 and an excellent power density of 4120Wkgelectrode−1 were obtained.展开更多
Asymmetric behaviors of capacitance and charging dynamics in the cathode and anode are general for nanoporous supercapacitors.Understanding this behavior is essential for the optimal design of supercapacitors.Herein,w...Asymmetric behaviors of capacitance and charging dynamics in the cathode and anode are general for nanoporous supercapacitors.Understanding this behavior is essential for the optimal design of supercapacitors.Herein,we perform constant-potential molecular dynamics simulations to reveal asymmetric features of porous supercapacitors and their effects on capacitance and charging dynamics.Our simulations show that,counterintuitively,charging dynamics can be fast in pores providing slow ion diffusion and vice versa.Unlike electrodes with singlesize pores,multi-pore electrodes show overcharging and accelerated co-ion desorption,which can be attributed to the subtle interplay between the dynamics and charging mechanisms.We find that capacitance and charging dynamics correlate with how the ions respond to an applied cell voltage in the cathode and anode.We demonstrate that symmetrizing this response can help boost power density,which may find practical applications in supercapacitor optimization.展开更多
The nanoporous Cu_(2-x)Se with Cu(Se-5%)surface catalysts were prepared through in situ dynamic restructuring strategy during the electrochemical process,which achieves highly selective electrochemical CO_(2) reductio...The nanoporous Cu_(2-x)Se with Cu(Se-5%)surface catalysts were prepared through in situ dynamic restructuring strategy during the electrochemical process,which achieves highly selective electrochemical CO_(2) reduction to methanol.In situ and quasi-operando spectroscopic results provide a deep insight into the catalytic active centres of reconstructed heterogeneous catalysts for CO_(2) electroreduction.展开更多
Molecular dynamics method was used to establish composite wall/inorganic nanopores of three pore sizes, three shale oil systems, five CO_(2)-cosolvent systems, and pure CO_(2) system. The process of CO_(2)-cosolvent d...Molecular dynamics method was used to establish composite wall/inorganic nanopores of three pore sizes, three shale oil systems, five CO_(2)-cosolvent systems, and pure CO_(2) system. The process of CO_(2)-cosolvent displacement of crude oil in shale nanopores and carbon storage was simulated and the influencing factors of displacement and storage were analyzed. It is shown that the attraction of the quartz wall to shale oil increases with the degree of hydroxylation. The higher the degree of quartz hydroxylation, the more difficult it is to extract the polar components of shale oil. Nanopore size also has a great impact on shale oil displacement efficiency. The larger the pore size, the higher the shale oil displacement efficiency. The closer the cosolvent molecules are to the polarity of the shale oil, the higher the mutual solubility of CO_(2) and shale oil. The more the non-polar components of shale oil, the lower the mutual solubility of CO_(2) and shale oil with highly polar cosolvent. Ethyl acetate is more effective in stripping relatively high polar shale oil, while dimethyl ether is more effective in stripping relatively low polar shale oil. Kerogen is highly adsorptive, especially to CO_(2). The CO_(2) inside the kerogen is not easy to diffuse and leak, thus allowing for a stable carbon storage. The highest CO_(2) storage rate is observed when dimethyl ether is used as a cosolvent, and the best storage stability is observed when ethyl acetate is used as a cosolvent.展开更多
Sulfur doped carbonaceous materials are promising anodes for potassium-ion batteries because of their ability to bridge active sites and induce C/S electron coupling,resulting in increased ion storage capacitance Howe...Sulfur doped carbonaceous materials are promising anodes for potassium-ion batteries because of their ability to bridge active sites and induce C/S electron coupling,resulting in increased ion storage capacitance However,the large potassium ions could cause significant volume expansion and structure collapse during operation in sulfur doped carbonaceous anodes,which lead to rapidly capacity sacrifice during long-term cycling.Nanopore design for anchoring sulfur atom in carbon skeleton is a novel way to alleviate the structure collapse and maintain the cycling stability.Therefore,this study developed a controlled nanopore and sulfur doped carbon sphere structure(S-NPHCSs).In potassium-ion batteries S-NPHCSs anode demonstrated exceptional performance with a high reversible capacity of 247 mAh·g^(–1)after 50 cycles at 0.2 A·g^(–1)and delivered a long cycle stability of 600 cycles at a high current density of 1.0 A·g^(–1).Interconnected nanopores and doped sulfur structure not only expand the accumulation space and offer ample active sites for diffusion and adsorption of potassium ions,but also build stable channels through nanopore structure to ensure the cyclic stability.This finding provides a fundamental theory for designing nanopore structures and introducing sulfur doped carbonaceous materials to enhance capacitive potassium storage and long cycle stability.展开更多
Binary transition metal sulfides are hotly investigated in advanced energy storage devices because of their ultra-high reversible capacity.Nevertheless,the unsatisfied rate capability and cycling stability still hinde...Binary transition metal sulfides are hotly investigated in advanced energy storage devices because of their ultra-high reversible capacity.Nevertheless,the unsatisfied rate capability and cycling stability still hinder their practical application.Herein,hierarchical nanoporous carbon@NiCo_(2)S_(4)(HNCMs@NCS)composites with coreshell flower-like structures were prepared by in situ growing of NiCo_(2)S_(4) nanosheets on HNCMs through a hydro thermal-as sis ted template sacrificial method.Benefiting from a synergistic effect between the NiCo_(2)S_(4)shell with high specific capacity and the HNCMs with unique porous structure,the synthesized flower-like HNCMs@NCS composites exhibit extraordinary electrochemical performances,including a high capacity of 346.9 mAh·g^(-1)at 1 A·g^(-1),superb rate property with86.4%initial capacity at 30 A·g^(-1)and predominant cycle stability with 81.2%capacity retention after 5000 cycles.Furthermore,the resulting HNCMs@NCS cathode was coupled with the chemical-activated HNCMs(AHNCMs)anode to construct a hybrid supercapacitor device.The asfabricated device exhibits superior energy density(49.9 Wh·kg^(-1)at 802 W·kg^(-1))and ultra-high power density(24 kW·kg^(-1)at 29.5 Wh·kg^(-1)).This fascinating result further demonstrates the tremendous prospect of the synthesized HNCMs@NCS composites as high-performance supercapacitor electrode materials.展开更多
Capacitance for electrostatic adsorption forms primarily within a Debye length of the electrode surface. Capacitive carbon electrodes were derivatized with ionic groups by means of adsorbing a surfactant in order to t...Capacitance for electrostatic adsorption forms primarily within a Debye length of the electrode surface. Capacitive carbon electrodes were derivatized with ionic groups by means of adsorbing a surfactant in order to test the theory that attached ionic groups would exclude co-ions and increase coulombic efficiency without the need for an added charge barrier membrane. It has been discovered that capacitive electrodes surface derivatized with ionic groups become polarized and intrinsically more coulombically efficient.展开更多
基于商用铸造Mg-Si合金,采用化学腐蚀和碳包覆技术相结合,制备出纳米多孔硅/碳复合负极。通过SEM、XRD和EDS技术表征了该负极的物相构成、化学成分和微观结构,并对其电化学性能进行了研究。结果表明,该负极具有典型的三维双连通纳米多...基于商用铸造Mg-Si合金,采用化学腐蚀和碳包覆技术相结合,制备出纳米多孔硅/碳复合负极。通过SEM、XRD和EDS技术表征了该负极的物相构成、化学成分和微观结构,并对其电化学性能进行了研究。结果表明,该负极具有典型的三维双连通纳米多孔结构,且碳层均匀包覆在多孔硅表面。0.1 C电流密度下,该负极首次充/放电比容量为724.44/1404.49 m A·h/g,循环寿命800次以上,且在-30~50℃的温度范围内可正常使用。展开更多
Nanoporous carbons(NPCs) derived from metal–organic frameworks(MOFs) are attracting increasing attention in many areas by virtue of their high specific surface area, large pore volume and unique porosity. The pre...Nanoporous carbons(NPCs) derived from metal–organic frameworks(MOFs) are attracting increasing attention in many areas by virtue of their high specific surface area, large pore volume and unique porosity. The present work reports the preparation of an NPC with high surface area(1731 m^2/g) and pore volume(1.68 cm^3/g) by direct carbonization of MOF-5. We examined the adsorption of three typical contaminants from aqueous solutions, i.e., sulfamethoxazole(SMX),bisphenol A(BPA) and methyl orange(MO), by using the as-prepared NPC. The results demonstrated that NPC could adsorb the contaminants effectively, with adsorption capacity(qm) of 625 mg/g(SMX), 757 mg/g(BPA) and 872 mg/g(MO), respectively. These values were approximately 1.0-3.2 times higher than those obtained for single-walled carbon nanotubes(SWCNTs) and commercial powder active carbon(PAC) under the same conditions. With its high surface area and unique meso/macropore structure, the enhanced adsorption of NPC most likely originates from the cooperative interaction of a pore-filling mechanism, electrostatic interaction,and hydrogen bonding. In particular, the p H value has a crucial impact on adsorption, suggesting the significant contribution of electrostatic interaction between NPC and the contaminants. This study provides a proof-of-concept demonstration of MOF-derived nanoporous carbons as effective adsorbents of contaminants for water treatment.展开更多
Carbonic anhydrase accounts for catalytic reaction of CO_(2)/HCO_(3)^(–) transformation, thus resulting in neutralization and acidification of the cellular environment, thereby favoring tumor development. Hence, it i...Carbonic anhydrase accounts for catalytic reaction of CO_(2)/HCO_(3)^(–) transformation, thus resulting in neutralization and acidification of the cellular environment, thereby favoring tumor development. Hence, it is a classical protein model of greatly biocatalytic significance as well as a highly expressed biomarker with renal tumor. We herein proposed a single-molecule measurement on carbonic anhydrase using MspA nanopore, in [BMIM+] and asymmetric K^(+)/Ca^(2+) cationic coordinated environment, instead of usual symmetric KCl/NaCl electrolyte. Significantly, our empirical analysis showed that asymmetric K^(+)/Ca^(2+) cationic environment contributes to distinguishable current modulations, thus yielding better resolution for carbonic anhydrase measurement, which is independent of applied voltage and more importantly, is stable enough at varied pH conditions and for very low concentration test in urine sample. Our results provide a classical model for nanopore protein analysis, and may also permit biocatalytic measurement at single-molecule level.展开更多
基金the National Natural Science Foundation of China(No.20976197) for its financial support of this project
文摘With high surface area,open porosity and high efficiency,a catalyst was prepared and firstly employed in electrocatalytic reduction of CO2 and electrosynthesis of dimethyl carbonate(DMC).The electrochemical property for electrocatalytic reduction of CO2 in ionic liquid was studied by cyclic voltammogram(CV).The effects of various reaction variables like temperature,working potential and cathode materials on the electrocatalytic performance were also investigated.80%yield of DMC was obtained under the optimal reaction conditions.
基金supported by the National Postdoctoral Program(2020M672782)National Natural Science Foundation of China(No.U1663225)+2 种基金Changjiang Scholars and Innovative Research Team in University(No.IRT15R52)National 111 project from the Ministry of Science and Technologythe Ministry of Education of China and the National Key R&D Program of China(No.2016YFA0202602)。
文摘Lithium-selenium(Li-Se)battery has attracted growing attention.Nevertheless,its practical application is still impeded by the shuttle effect of the formed polyselenides.Herein,we report in-situ hydrothermal weaving the three-dimensional(3 D)highly conductive hierarchically interconnected nanoporous web by threading microporous metal organic framework MIL-68(Al)crystals onto multi-walled carbon nanotubes(MWCNTs).Such 3 D hierarchically nanoporous web(3 D MIL-68(Al)@MWCNTs web)with a very high surface area,a large amount of micropores,electrical conductivity and elasticity strongly traps the soluble polyselenides during the electrochemical reaction and significantly facilitates lithium ion diffusion and electron transportation.Molecular dynamic calculation confirmed the strong affinity of MIL-68(Al)for the adsorption of polyselenides,quite suitable for Li-Se battery.Their hexahedral channels(1.56 nm)are more efficient for the confinement of polyselenides and for the diffusion of electrolytes compared to their smaller triangular channels(0.63 nm).All these excellent characteristics of 3 D MIL-68(Al)@MWCNTs web with suitable confinement of a large amount of selenium and the conductive linkage between MIL-68(Al)host by MWCNTs result in a high capacity of 453 m Ah/g at 0.2 C with 99.5%coulombic efficiency after 200 cycles with significantly improved cycle stability and rate performance.The 3 D MIL-68(Al)@MWCNTs web presents a good performance in Li-Se battery in term of the specific capacity and cycling stability and also in terms of rate performance compared with all the metal-organic framework(MOF)based or MOF derived porous carbons used in Li-Se battery.
基金supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF)Funded by the Ministry of Education(NRF-2019R1A2C1084836,NRF-2018M1A2A2061994,and NRF-2021R1A4A2001403)the KU-KIST School Program。
文摘Rechargeable aluminum batteries(RABs),which use earth-abundant and high-volumetric-capacity metal anodes(8040 m Ah cm-3),have great potential as next-generation power sources because they use cheaper resources to deliver higher energies,compared to current lithium ion batteries.However,the mechanism of charge delivery in the newly developed,ionic liquid-based electrolytic system for RABs differs from that in conventional organic electrolytes.Thus,targeted research efforts are required to address the large overpotentials and cycling decay encountered in the ionic liquid-based electrolytic system.In this study,a nanoporous carbon(NPC)electrode with well-developed nanopores is used to develop a high-performance aluminum anode.The negatively charged nanopores can provide quenched dynamics of electrolyte molecules in the aluminum deposition process,resulting in an increased collision rate.The fast chemical equilibrium of anionic species induced by the facilitated anionic collisions leads to more favorable reduction reactions that form aluminum metals.The nanoconfinement effect causes separated nucleation and growth of aluminum nanoparticles in the multiple confined nanopores,leading to higher coulombic efficiencies and more stable cycling performance compared with macroporous carbon black and 2D stainless steel electrodes.
基金Project (20060532006) supported by Specialized Research Fund for the Doctoral Program of Higher Education
文摘A new nanocomposite material for construction of glucose biosensor was prepared. The biosensor was formed by entrapping glucose oxidase(Gox) into chitosan/nanoporous ZrO2/multiwalled carbon nanotubes nanocomposite film. In this biosensing thin film, the multiwalled carbon nanotubes can effectively catalyze hydrogen peroxide and nanoporous ZrO2 can enhance the stability of the immobilized enzyme. The resulting biosensor provides a very effective matrix for the immobilization of glucose oxidase and exhibits a wide linear response range from 8 μmol/L to 3 mmol/L with a correlation coefficient of 0.994 for the detection of glucose. And the response time and detection limit of the biosensor are determined to be 6 s and 3.5 μmol/L, respectively. Another attractive characteristic is that the biosensor is inexpensive, stable and reliable.
文摘Nanoporous carbons were synthesized using furfuryl alcohol and sucrose as precursors and MCM-41 and mordenite as nanoporous templates.The produced nanoporous carbons were used as adsorbent for methane storage.The average pore diameter of the samples varied from 3.9 nm to 5.9 nm and the BET surface area varied from 320m2/g to 824m2/g.The volumetric adsorption experiments revealed that MCM-41 and sucrose had better performance compared with mordenite and furfuryl alcohol,correspondingly.Also,the effect of precursor to template ratio on the structure of nanoporous carbons and their adsorption capacities was investigated.The nanoporous carbon produced from MCM-41 mesoporous molecular sieve partially filled by sucrose shows the best methane adsorption capacity among the tested samples.
基金National Research Foundation of Korea,Grant/Award Numbers:2019R1A2C1084836,2021R1A4A2001403。
文摘Studies on three-dimensional structured carbon templates have focused on how to guide homogeneous lithium metal nucleation and growth for lithium metal anodes(LMAs).However,there is still insufficient evidence for a key factor to achieve their high electrochemical performance.Here,the effects of nanopores and sulfur doping on carbon-based nanoporous host(CNH)electrode materials for LMAs were investigated using natural polymer-derived CNHs.Homogeneous pore-filling behaviors of lithium metal in the nanopores of the CNH electrode materials were first observed by ex situ scanning electron microscopy analysis,where the protective lithium metal nucleation and growth process led to significantly high Coulombic efficiency(CE)of~99.4%and stable 600 cycles.In addition,a comparison study of CNH and sulfurdoped CNH(S-CNH)electrodes,which differ only in the presence or absence of sulfur,revealed that sulfur doping can cause lower electrochemical series resistance,higher CE value,and better cycling stability in a wide range of current densities and number of cycles.Moreover,S-CNH-based LMAs showed high electrochemical performance in full-cell Li-S battery tests using a sulfur copolymer cathode,where a high energy density of 1370Wh kgelectrode−1 and an excellent power density of 4120Wkgelectrode−1 were obtained.
基金funding support from the National Natural Science Foundation of China(51876072)the Hubei Provincial Natural Science Foundation of China(2019CFA002,2020CFA093)supported by the Program for HUST Academic Frontier Youth Team
文摘Asymmetric behaviors of capacitance and charging dynamics in the cathode and anode are general for nanoporous supercapacitors.Understanding this behavior is essential for the optimal design of supercapacitors.Herein,we perform constant-potential molecular dynamics simulations to reveal asymmetric features of porous supercapacitors and their effects on capacitance and charging dynamics.Our simulations show that,counterintuitively,charging dynamics can be fast in pores providing slow ion diffusion and vice versa.Unlike electrodes with singlesize pores,multi-pore electrodes show overcharging and accelerated co-ion desorption,which can be attributed to the subtle interplay between the dynamics and charging mechanisms.We find that capacitance and charging dynamics correlate with how the ions respond to an applied cell voltage in the cathode and anode.We demonstrate that symmetrizing this response can help boost power density,which may find practical applications in supercapacitor optimization.
基金supported by the National Natural Science Foundation of China(51771072)the Outstanding Youth Scientist Foundation of Hunan Province(2020JJ2006)+2 种基金the Youth 1000 Talent Program of ChinaFundamental Research Funds for the Central UniversitiesHunan University State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body Independent Research Project(71860007)。
文摘The nanoporous Cu_(2-x)Se with Cu(Se-5%)surface catalysts were prepared through in situ dynamic restructuring strategy during the electrochemical process,which achieves highly selective electrochemical CO_(2) reduction to methanol.In situ and quasi-operando spectroscopic results provide a deep insight into the catalytic active centres of reconstructed heterogeneous catalysts for CO_(2) electroreduction.
基金Supported by National Natural Science Foundation of China(52304021,52204031)Natural Science Foundation of Sichuan Province(2022NSFSC0205)National Science and Technology Major Project of China(2017ZX05049006-010).
文摘Molecular dynamics method was used to establish composite wall/inorganic nanopores of three pore sizes, three shale oil systems, five CO_(2)-cosolvent systems, and pure CO_(2) system. The process of CO_(2)-cosolvent displacement of crude oil in shale nanopores and carbon storage was simulated and the influencing factors of displacement and storage were analyzed. It is shown that the attraction of the quartz wall to shale oil increases with the degree of hydroxylation. The higher the degree of quartz hydroxylation, the more difficult it is to extract the polar components of shale oil. Nanopore size also has a great impact on shale oil displacement efficiency. The larger the pore size, the higher the shale oil displacement efficiency. The closer the cosolvent molecules are to the polarity of the shale oil, the higher the mutual solubility of CO_(2) and shale oil. The more the non-polar components of shale oil, the lower the mutual solubility of CO_(2) and shale oil with highly polar cosolvent. Ethyl acetate is more effective in stripping relatively high polar shale oil, while dimethyl ether is more effective in stripping relatively low polar shale oil. Kerogen is highly adsorptive, especially to CO_(2). The CO_(2) inside the kerogen is not easy to diffuse and leak, thus allowing for a stable carbon storage. The highest CO_(2) storage rate is observed when dimethyl ether is used as a cosolvent, and the best storage stability is observed when ethyl acetate is used as a cosolvent.
基金supported by the Key R&D Plan of Jihua Laboratory(Nos.X200191TL200 and X220301XS220)Guangdong Basic and Applied Basic Research Foundation(No.2022A1515110052)+1 种基金Foshan Postdoctoral Science Foundation(Nos.X221071MS210)Numerical computations were performed on Hefei advanced computing center。
文摘Sulfur doped carbonaceous materials are promising anodes for potassium-ion batteries because of their ability to bridge active sites and induce C/S electron coupling,resulting in increased ion storage capacitance However,the large potassium ions could cause significant volume expansion and structure collapse during operation in sulfur doped carbonaceous anodes,which lead to rapidly capacity sacrifice during long-term cycling.Nanopore design for anchoring sulfur atom in carbon skeleton is a novel way to alleviate the structure collapse and maintain the cycling stability.Therefore,this study developed a controlled nanopore and sulfur doped carbon sphere structure(S-NPHCSs).In potassium-ion batteries S-NPHCSs anode demonstrated exceptional performance with a high reversible capacity of 247 mAh·g^(–1)after 50 cycles at 0.2 A·g^(–1)and delivered a long cycle stability of 600 cycles at a high current density of 1.0 A·g^(–1).Interconnected nanopores and doped sulfur structure not only expand the accumulation space and offer ample active sites for diffusion and adsorption of potassium ions,but also build stable channels through nanopore structure to ensure the cyclic stability.This finding provides a fundamental theory for designing nanopore structures and introducing sulfur doped carbonaceous materials to enhance capacitive potassium storage and long cycle stability.
基金financially supported by the National Natural Science Foundation of China(No.52174247)the Distinguish Young Scientists of Hunan province(No.2022JJ10024)+2 种基金"Hejian"Innovative Talent Project of Hunan Province(No.2022RC1088)the Natural Science Foundation of Hunan Province(Nos.2021JJ30212 and 2021JJ30216)the Scientific Research and Innovation Foundation of Hunan University of Technology(No.CX2209)。
文摘Binary transition metal sulfides are hotly investigated in advanced energy storage devices because of their ultra-high reversible capacity.Nevertheless,the unsatisfied rate capability and cycling stability still hinder their practical application.Herein,hierarchical nanoporous carbon@NiCo_(2)S_(4)(HNCMs@NCS)composites with coreshell flower-like structures were prepared by in situ growing of NiCo_(2)S_(4) nanosheets on HNCMs through a hydro thermal-as sis ted template sacrificial method.Benefiting from a synergistic effect between the NiCo_(2)S_(4)shell with high specific capacity and the HNCMs with unique porous structure,the synthesized flower-like HNCMs@NCS composites exhibit extraordinary electrochemical performances,including a high capacity of 346.9 mAh·g^(-1)at 1 A·g^(-1),superb rate property with86.4%initial capacity at 30 A·g^(-1)and predominant cycle stability with 81.2%capacity retention after 5000 cycles.Furthermore,the resulting HNCMs@NCS cathode was coupled with the chemical-activated HNCMs(AHNCMs)anode to construct a hybrid supercapacitor device.The asfabricated device exhibits superior energy density(49.9 Wh·kg^(-1)at 802 W·kg^(-1))and ultra-high power density(24 kW·kg^(-1)at 29.5 Wh·kg^(-1)).This fascinating result further demonstrates the tremendous prospect of the synthesized HNCMs@NCS composites as high-performance supercapacitor electrode materials.
文摘Capacitance for electrostatic adsorption forms primarily within a Debye length of the electrode surface. Capacitive carbon electrodes were derivatized with ionic groups by means of adsorbing a surfactant in order to test the theory that attached ionic groups would exclude co-ions and increase coulombic efficiency without the need for an added charge barrier membrane. It has been discovered that capacitive electrodes surface derivatized with ionic groups become polarized and intrinsically more coulombically efficient.
文摘基于商用铸造Mg-Si合金,采用化学腐蚀和碳包覆技术相结合,制备出纳米多孔硅/碳复合负极。通过SEM、XRD和EDS技术表征了该负极的物相构成、化学成分和微观结构,并对其电化学性能进行了研究。结果表明,该负极具有典型的三维双连通纳米多孔结构,且碳层均匀包覆在多孔硅表面。0.1 C电流密度下,该负极首次充/放电比容量为724.44/1404.49 m A·h/g,循环寿命800次以上,且在-30~50℃的温度范围内可正常使用。
基金supported by the National Natural Science Foundation of China (Nos. 21437001 and 21407019)Open Project of State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (No. QA201617)
文摘Nanoporous carbons(NPCs) derived from metal–organic frameworks(MOFs) are attracting increasing attention in many areas by virtue of their high specific surface area, large pore volume and unique porosity. The present work reports the preparation of an NPC with high surface area(1731 m^2/g) and pore volume(1.68 cm^3/g) by direct carbonization of MOF-5. We examined the adsorption of three typical contaminants from aqueous solutions, i.e., sulfamethoxazole(SMX),bisphenol A(BPA) and methyl orange(MO), by using the as-prepared NPC. The results demonstrated that NPC could adsorb the contaminants effectively, with adsorption capacity(qm) of 625 mg/g(SMX), 757 mg/g(BPA) and 872 mg/g(MO), respectively. These values were approximately 1.0-3.2 times higher than those obtained for single-walled carbon nanotubes(SWCNTs) and commercial powder active carbon(PAC) under the same conditions. With its high surface area and unique meso/macropore structure, the enhanced adsorption of NPC most likely originates from the cooperative interaction of a pore-filling mechanism, electrostatic interaction,and hydrogen bonding. In particular, the p H value has a crucial impact on adsorption, suggesting the significant contribution of electrostatic interaction between NPC and the contaminants. This study provides a proof-of-concept demonstration of MOF-derived nanoporous carbons as effective adsorbents of contaminants for water treatment.
基金National Key Research and Development Program of China(2022YFB3205600)Chongqing Talents:Exceptional Young Talents Project(cstc2021ycjh-bgzxm0016)+1 种基金Beibei Technology Talents and Independent Innovation Project(No.2022-34)the Natural Science Foundation of Chongqing,China(cstc2021jcyj-jqx0030).
文摘Carbonic anhydrase accounts for catalytic reaction of CO_(2)/HCO_(3)^(–) transformation, thus resulting in neutralization and acidification of the cellular environment, thereby favoring tumor development. Hence, it is a classical protein model of greatly biocatalytic significance as well as a highly expressed biomarker with renal tumor. We herein proposed a single-molecule measurement on carbonic anhydrase using MspA nanopore, in [BMIM+] and asymmetric K^(+)/Ca^(2+) cationic coordinated environment, instead of usual symmetric KCl/NaCl electrolyte. Significantly, our empirical analysis showed that asymmetric K^(+)/Ca^(2+) cationic environment contributes to distinguishable current modulations, thus yielding better resolution for carbonic anhydrase measurement, which is independent of applied voltage and more importantly, is stable enough at varied pH conditions and for very low concentration test in urine sample. Our results provide a classical model for nanopore protein analysis, and may also permit biocatalytic measurement at single-molecule level.