The development of efficient single-atom catalysts(SACs) for the oxygen reduction reaction(ORR)remains a formidable challenge,primarily due to the symmetric charge distribution of metal singleatom sites(M-N_(4)).To ad...The development of efficient single-atom catalysts(SACs) for the oxygen reduction reaction(ORR)remains a formidable challenge,primarily due to the symmetric charge distribution of metal singleatom sites(M-N_(4)).To address such issue,herein,Fe-N_(x) sites coupled synergistic catalysts fabrication strategy is presented to break the uniform electronic distribution,thus enhancing the intrinsic catalytic activity.Precisely,atomically dispersed Fe-N_(x) sites supported on N/S-doped mesoporous carbon(NSC)coupled with FeS@C core-shell nanoparticles(FAS-NSC@950) is synthesized by a facile hydrothermal reaction and subsequent pyrolysis.Due to the presence of an in situ-grown conductive graphitic layer(shell),the FeS nanoparticles(core) effectively adjust the electronic structure of single-atom Fe sites and facilitate the ORR kinetics via short/long-range coupling interactions.Consequently,FAS-NSC@950displays a more positive half-wave potential(E_(1/2)) of 0.871 V with a significantly boosted ORR kinetics(Tafel slope=52.2 mV dec^(-1)),outpacing the commercial Pt/C(E_(1/2)=0.84 V and Tafel slope=54.6 mV dec^(-1)).As a bifunctional electrocatalyst,it displays a smaller bifunctional activity parameter(ΔE) of 0.673 V,surpassing the Pt/C-RuO_(2) combination(ΔE=0.724 V).Besides,the FAS-NSC@950-based zincair battery(ZAB) displays superior power density,specific capacity,and long-term cycling performance to the Pt/C-Ir/C-based ZAB.This work significantly contributes to the field by offering a promising strategy to enhance the catalytic activity of SACs for ORR,with potential implications for energy conversion and storage technologies.展开更多
Efficient bifunctional oxygen electrocatalysts for ORR and OER are fundamental to the development of high performance metal-air batteries.Herein,a facile cost-efficient two-step pyrolysis strategy for the fabrication ...Efficient bifunctional oxygen electrocatalysts for ORR and OER are fundamental to the development of high performance metal-air batteries.Herein,a facile cost-efficient two-step pyrolysis strategy for the fabrication of a bifunctional oxygen electrocatalyst has been proposed.The efficient non-preciousmetal-based electrocatalyst,Fe/Fe_(3)C@Fe-N_(x)-C consists of highly curved onion-like carbon shells that encapsulate Fe/Fe_(3)C nanoparticles,distributed on an extensively porous graphitic carbon aerogel.The obtained Fe/Fe_(3)C@Fe-N_(x)-C aerogel exhibited superb electrochemical activity,excellent durability,and high methanol tolerance.The experimental results indicated that the assembly of onion-like carbon shells with encapsulated Fe/Fe_(3)C yielded highly curved carbon surfaces with abundant Fe-Nxactive sites,a porous structure,and enhanced electrocatalytic activity towards ORR and OER,hence displaying promising potential for application as an air cathode in rechargeable Zn-air batteries.The constructed Zn-air battery possessed an exceptional peak power density of~147 mW cm^(-2),outstanding cycling stability(200 cycles,1 h per cycle),and a small voltage gap of 0.87 V.This study offers valuable insights regarding the construction of low-cost and highly active bifunctional oxygen electrocatalysts for efficient air batteries.展开更多
We previously reported that postsynaptic density-93 mediates neuron-microglia crosstalk by interacting with amino acids 357–395 of C-X3-C motif chemokine ligand 1(CX3 CL1) to induce microglia polarization. More impor...We previously reported that postsynaptic density-93 mediates neuron-microglia crosstalk by interacting with amino acids 357–395 of C-X3-C motif chemokine ligand 1(CX3 CL1) to induce microglia polarization. More importantly, the peptide Tat-CX3 CL1(comprising amino acids 357–395 of CX3 CL1) disrupts the interaction between postsynaptic density-93 and CX3 CL1, reducing neurological impairment and exerting a protective effect in the context of acute ischemic stroke. However, the mechanism underlying these effects remains unclear. In the current study, we found that the pro-inflammatory M1 phenotype increased and the anti-inflammatory M2 phenotype decreased at different time points. The M1 phenotype increased at 6 hours after stroke and peaked at 24 hours after perfusion, whereas the M2 phenotype decreased at 6 and 24 hours following reperfusion. We found that the peptide Tat-CX3 CL1(357–395 aa) facilitates microglial polarization from M1 to M2 by reducing the production of soluble CX3 CL1. Furthermore, the a disintegrin and metalloprotease domain 17(ADAM17) inhibitor GW280264 x, which inhibits metalloprotease activity and prevents CX3 CL1 from being sheared into its soluble form, facilitated microglial polarization from M1 to M2 by inhibiting soluble CX3 CL1 formation. Additionally, Tat-CX3 CL1(357–395 aa) attenuated long-term cognitive deficits and improved white matter integrity as determined by the Morris water maze test at 31–34 days following surgery and immunofluorescence staining at 35 days after stroke, respectively. In conclusion, Tat-CX3 CL1(357–395 aa) facilitates functional recovery after ischemic stroke by promoting microglial polarization from M1 to M2. Therefore, the Tat-CX3 CL1(357–395 aa) is a potential therapeutic agent for ischemic stroke.展开更多
Binder-free bifunctional electrocatalysts are attractive for rechargeable Zn-air batteries(ZABs)in gridscale energy storage and flexible electronics,but suffering from the sluggish mass transport and inadequate cataly...Binder-free bifunctional electrocatalysts are attractive for rechargeable Zn-air batteries(ZABs)in gridscale energy storage and flexible electronics,but suffering from the sluggish mass transport and inadequate catalytic capability.Herein,we propose a scalable approach of in-situ engineering highly exposed Fe-N_(4)/Cxsites on the N,S-doped porous carbon nanofiber membrane as a binder-free air electrode catalyst for ZABs.ZnS nanospheres are firstly used as integrated structure-directing agents to facilitate the electronic modulation of Fe-N_(4)/Cxsites by S doping and construct the hierarchical macro/meso/micropores at high temperature.Neither additional step for removal of ZnS nanospheres nor doping process is required,significantly simplifying the pore formation process and improving the S doping efficiency.Benefiting from the enhanced intrinsic activity of high-density Fe-N_(4)/Cxsites(23.53μmol g^(-1))and the optimized mass transport of carbon nanofibers,as-synthesized electrocatalyst shows a positive half-wave potential of 0.89 V for oxygen reduction reaction and a small overpotential of 0.47 V at 10 m A cm^(-2)for oxygen evolution reaction.When used as the air cathode catalyst for ZABs,it delivers a high specific capacity of 699 m Ah g^(-1)at 5 m A cm^(-2),a large peak power density of 228 m W cm^(-2)and a prolonged cycling over 1000 h.At 10 m A cm^(-2),a robust structure with atomically dispersed Fe is also remained after cycling for 420 h.Due to the flexible properties of the electrocatalyst,as-assembled quasi-solid-state ZAB shows stable cycling over 90 h at alternately flat/bent states,demonstrating great prospects in flexible electronic device applications.展开更多
In order to address the issues of low initial Coulombic efficiency of SiO_(x)-C composite anode due to the formation of solid electrolyte interphase,irreversible conversion reaction,and large volume change,the prelith...In order to address the issues of low initial Coulombic efficiency of SiO_(x)-C composite anode due to the formation of solid electrolyte interphase,irreversible conversion reaction,and large volume change,the prelithiation method using metal lithium has been employed as one of effective solutions.However,violent side reactions with liquid electrolyte for prelithiation lead to low prelithiation efficiency and induce poor interface between the SiO_(x)-C electrode and liquid electrolyte.Here,a new prelithiation method with so called solid-state corrosion of lithium is developed.By replacing liquid electrolyte with solid-state electrolyte of carbon-incorporated lithium phosphorus oxynitride(LiCPON),not only various side reactions associated with metal lithium are avoided,but also the perfect interface is achieved from the decomposition products of LiCPON.The successful implementation of solid-state corrosion prelithiation can be confirmed by changes in optical image,scanning electron microscopy,and X-ray diffraction.Compared with pristine electrode,the initial Coulombic efficiency of the prelithiated electrode using solid electrolyte can be increased by about 10%,reaching 98.6%in half cell and 88.9%in full cell.Compared with prelithiated electrode using liquid electrolyte,the prelithiation efficiency of the prelithiated anode with solid-state corrosion can be increased from 25.7%to 82.8%.Solid-state corrosion of lithium is expected to become a useful method for prelithiation of SiO_(x)-C composite electrode with high initial Coulombic efficiency and large prelithiation efficiency.展开更多
N-doped carbon-based single-atom catalysts(NC-SACs) are widely researched in various electrochemical reactions due to high metal atom utilization and catalytic activity.The catalytic activity of NC-SACs originates fro...N-doped carbon-based single-atom catalysts(NC-SACs) are widely researched in various electrochemical reactions due to high metal atom utilization and catalytic activity.The catalytic activity of NC-SACs originates from the coordinating structure between single metal site(M) and the doped nitrogen(N) in carbon matrix by forming M-N_(x)-C structure(1≤x≤4).The M-N4-C structure is widely considered to be the most stable and effective catalytic site.However,there is no in-depth research for the "x" modulation in Pt-Nx-C structure and the corresponding catalytic properties.Herein,atomically dispersed Pt on N-doped carbon(Pt-NC) with Pt-Nx-C structure(1≤x≤4),as a research model,is fabricated by a ZIF-8 template and applied to catalytic oxygen reduction.Different carbonization temperatures are used to control N loss,and then modulate the N coordination of Pt-Nx-C structure.The Pt-NC has the predictable low half-wave potential(E_(1/2)) of 0.72 V vs RHE compared to the Pt/C 20% of 0.81 V due to low Pt content.Remarkably,the Pt-NC shows a high onset potential(1.10 V vs RHE,determined for j=-0.1 mA cm^(2)) and a high current density of 5.2 mA cm^(-2),more positive and higher than that of Pt/C 20%(0.96 V) and 4.9 mA cm^(-2),respectively.As the structural characterization and DFT simulation confirmed,the reducing PtN coordination number induces low valence of Pt atoms and low free energy of oxygen reduction,which is responsible for the improved catalytic activity.Furthermore,the Pt-NC shows high mass activity(172 times higher than that of Pt/C 20%),better stability and methanol crossover resistance.展开更多
Bisphenol A(BPA)has received increasing attention due to its long-term industrial application and persistence in environmental pollution.Iron-based carbon catalyst activation of peroxymonosulfate(PMS)shows a good pros...Bisphenol A(BPA)has received increasing attention due to its long-term industrial application and persistence in environmental pollution.Iron-based carbon catalyst activation of peroxymonosulfate(PMS)shows a good prospect for effective elimination of recalcitrant contaminants in water.Herein,considering the problem about the leaching of iron ions and the optimization of heteroatoms doping,the iron,nitrogen and sulfur co-doped tremellalike carbon catalyst(Fe-NS@C)was rationally designed using very little iron,S-C_(3)N_(4) and low-cost chitosan(CS)via the impregnation-calcination method.The as-prepared Fe-NS@C exhibited excellent performance for complete removal of BPA(20 mg/L)by activating PMS with the high kinetic constant(1.492 min^(−1))in 15 min.Besides,the Fe-NS@C/PMS system not only possessed wide pH adaptation and high resistance to environmental interference,but also maintained an excellent degradation efficiency on different pollutants.Impressively,increased S-C_(3)N_(4) doping amount modulated the contents of different N species in Fe-NS@C,and the catalytic activity of Fe-NS@C-1-x was visibly enhanced with increasing SC_(3)N_(4) contents,verifying pyridine N and Fe-Nx as main active sites in the system.Meanwhile,thiophene sulfur(C-S-C)as active sites played an auxiliary role.Furthermore,quenching experiment,EPR analysis and electrochemical test proved that surface-bound radicals(·OH and SO_(4)^(·−))and non-radical pathways worked in the BPA degradation(the former played a dominant role).Finally,possible BPA degradation route were proposed.This work provided a promising way to synthesize the novel Fe,N and S co-doping carbon catalyst for degrading organic pollutants with low metal leaching and high catalytic ability.展开更多
基金financially supported by the National Natural Science Foundation of China(21773024)the Natural Science Foundation of Sichuan Province of China(2023NSFC0084)the China Postdoctoral Science Foundation(2019M663469)。
文摘The development of efficient single-atom catalysts(SACs) for the oxygen reduction reaction(ORR)remains a formidable challenge,primarily due to the symmetric charge distribution of metal singleatom sites(M-N_(4)).To address such issue,herein,Fe-N_(x) sites coupled synergistic catalysts fabrication strategy is presented to break the uniform electronic distribution,thus enhancing the intrinsic catalytic activity.Precisely,atomically dispersed Fe-N_(x) sites supported on N/S-doped mesoporous carbon(NSC)coupled with FeS@C core-shell nanoparticles(FAS-NSC@950) is synthesized by a facile hydrothermal reaction and subsequent pyrolysis.Due to the presence of an in situ-grown conductive graphitic layer(shell),the FeS nanoparticles(core) effectively adjust the electronic structure of single-atom Fe sites and facilitate the ORR kinetics via short/long-range coupling interactions.Consequently,FAS-NSC@950displays a more positive half-wave potential(E_(1/2)) of 0.871 V with a significantly boosted ORR kinetics(Tafel slope=52.2 mV dec^(-1)),outpacing the commercial Pt/C(E_(1/2)=0.84 V and Tafel slope=54.6 mV dec^(-1)).As a bifunctional electrocatalyst,it displays a smaller bifunctional activity parameter(ΔE) of 0.673 V,surpassing the Pt/C-RuO_(2) combination(ΔE=0.724 V).Besides,the FAS-NSC@950-based zincair battery(ZAB) displays superior power density,specific capacity,and long-term cycling performance to the Pt/C-Ir/C-based ZAB.This work significantly contributes to the field by offering a promising strategy to enhance the catalytic activity of SACs for ORR,with potential implications for energy conversion and storage technologies.
基金supported financially by the National Natural Science Foundation of China,China(Grant No.51702180,51572136,91963113,21703116,51372127,51873096)The Scientific and Technical Development Project of Qingdao,China(Grant No.18-2-2-52-jch)+1 种基金The Taishan Scholar Advantage and Characteristic Discipline Team of Eco Chemical Process and TechnologyThe Natural Science Foundation of Hebei Province(B2019204009)。
文摘Efficient bifunctional oxygen electrocatalysts for ORR and OER are fundamental to the development of high performance metal-air batteries.Herein,a facile cost-efficient two-step pyrolysis strategy for the fabrication of a bifunctional oxygen electrocatalyst has been proposed.The efficient non-preciousmetal-based electrocatalyst,Fe/Fe_(3)C@Fe-N_(x)-C consists of highly curved onion-like carbon shells that encapsulate Fe/Fe_(3)C nanoparticles,distributed on an extensively porous graphitic carbon aerogel.The obtained Fe/Fe_(3)C@Fe-N_(x)-C aerogel exhibited superb electrochemical activity,excellent durability,and high methanol tolerance.The experimental results indicated that the assembly of onion-like carbon shells with encapsulated Fe/Fe_(3)C yielded highly curved carbon surfaces with abundant Fe-Nxactive sites,a porous structure,and enhanced electrocatalytic activity towards ORR and OER,hence displaying promising potential for application as an air cathode in rechargeable Zn-air batteries.The constructed Zn-air battery possessed an exceptional peak power density of~147 mW cm^(-2),outstanding cycling stability(200 cycles,1 h per cycle),and a small voltage gap of 0.87 V.This study offers valuable insights regarding the construction of low-cost and highly active bifunctional oxygen electrocatalysts for efficient air batteries.
基金supported by the National Natural Science Foundation of China,Nos. 82071304 (to QXZ), 81671149 (to QXZ),and 81971179 (to XML)the Natural Science Foundation of Jiangsu Province,Nos. BK20191463 (to XML) and BK20161167 (to QXZ)。
文摘We previously reported that postsynaptic density-93 mediates neuron-microglia crosstalk by interacting with amino acids 357–395 of C-X3-C motif chemokine ligand 1(CX3 CL1) to induce microglia polarization. More importantly, the peptide Tat-CX3 CL1(comprising amino acids 357–395 of CX3 CL1) disrupts the interaction between postsynaptic density-93 and CX3 CL1, reducing neurological impairment and exerting a protective effect in the context of acute ischemic stroke. However, the mechanism underlying these effects remains unclear. In the current study, we found that the pro-inflammatory M1 phenotype increased and the anti-inflammatory M2 phenotype decreased at different time points. The M1 phenotype increased at 6 hours after stroke and peaked at 24 hours after perfusion, whereas the M2 phenotype decreased at 6 and 24 hours following reperfusion. We found that the peptide Tat-CX3 CL1(357–395 aa) facilitates microglial polarization from M1 to M2 by reducing the production of soluble CX3 CL1. Furthermore, the a disintegrin and metalloprotease domain 17(ADAM17) inhibitor GW280264 x, which inhibits metalloprotease activity and prevents CX3 CL1 from being sheared into its soluble form, facilitated microglial polarization from M1 to M2 by inhibiting soluble CX3 CL1 formation. Additionally, Tat-CX3 CL1(357–395 aa) attenuated long-term cognitive deficits and improved white matter integrity as determined by the Morris water maze test at 31–34 days following surgery and immunofluorescence staining at 35 days after stroke, respectively. In conclusion, Tat-CX3 CL1(357–395 aa) facilitates functional recovery after ischemic stroke by promoting microglial polarization from M1 to M2. Therefore, the Tat-CX3 CL1(357–395 aa) is a potential therapeutic agent for ischemic stroke.
基金the financial support from the National Natural Science Foundation of China(51972191,52172047)the National Key Research and Development Program of China(2021YFA1200800)。
文摘Binder-free bifunctional electrocatalysts are attractive for rechargeable Zn-air batteries(ZABs)in gridscale energy storage and flexible electronics,but suffering from the sluggish mass transport and inadequate catalytic capability.Herein,we propose a scalable approach of in-situ engineering highly exposed Fe-N_(4)/Cxsites on the N,S-doped porous carbon nanofiber membrane as a binder-free air electrode catalyst for ZABs.ZnS nanospheres are firstly used as integrated structure-directing agents to facilitate the electronic modulation of Fe-N_(4)/Cxsites by S doping and construct the hierarchical macro/meso/micropores at high temperature.Neither additional step for removal of ZnS nanospheres nor doping process is required,significantly simplifying the pore formation process and improving the S doping efficiency.Benefiting from the enhanced intrinsic activity of high-density Fe-N_(4)/Cxsites(23.53μmol g^(-1))and the optimized mass transport of carbon nanofibers,as-synthesized electrocatalyst shows a positive half-wave potential of 0.89 V for oxygen reduction reaction and a small overpotential of 0.47 V at 10 m A cm^(-2)for oxygen evolution reaction.When used as the air cathode catalyst for ZABs,it delivers a high specific capacity of 699 m Ah g^(-1)at 5 m A cm^(-2),a large peak power density of 228 m W cm^(-2)and a prolonged cycling over 1000 h.At 10 m A cm^(-2),a robust structure with atomically dispersed Fe is also remained after cycling for 420 h.Due to the flexible properties of the electrocatalyst,as-assembled quasi-solid-state ZAB shows stable cycling over 90 h at alternately flat/bent states,demonstrating great prospects in flexible electronic device applications.
基金supported by the National Natural Science Foundation of China(No.22279022)the Joint Funds of the National Natural Science Foundation of China(No.U20A20336)the Tianmu Lake Institute of Advanced Energy Storage Technologies Scientist Studio Program(No.TIESSS0002).
文摘In order to address the issues of low initial Coulombic efficiency of SiO_(x)-C composite anode due to the formation of solid electrolyte interphase,irreversible conversion reaction,and large volume change,the prelithiation method using metal lithium has been employed as one of effective solutions.However,violent side reactions with liquid electrolyte for prelithiation lead to low prelithiation efficiency and induce poor interface between the SiO_(x)-C electrode and liquid electrolyte.Here,a new prelithiation method with so called solid-state corrosion of lithium is developed.By replacing liquid electrolyte with solid-state electrolyte of carbon-incorporated lithium phosphorus oxynitride(LiCPON),not only various side reactions associated with metal lithium are avoided,but also the perfect interface is achieved from the decomposition products of LiCPON.The successful implementation of solid-state corrosion prelithiation can be confirmed by changes in optical image,scanning electron microscopy,and X-ray diffraction.Compared with pristine electrode,the initial Coulombic efficiency of the prelithiated electrode using solid electrolyte can be increased by about 10%,reaching 98.6%in half cell and 88.9%in full cell.Compared with prelithiated electrode using liquid electrolyte,the prelithiation efficiency of the prelithiated anode with solid-state corrosion can be increased from 25.7%to 82.8%.Solid-state corrosion of lithium is expected to become a useful method for prelithiation of SiO_(x)-C composite electrode with high initial Coulombic efficiency and large prelithiation efficiency.
基金financially supported by the National Natural Science Foundation of China (Nos. 51572124 and 51702162)the Natural Science Foundation of Jiangsu Province (No. BK20180154and BK20180490)+1 种基金the Fundamental Research Funds for the Central Universities (No. 30920130111003)A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD, China)。
文摘N-doped carbon-based single-atom catalysts(NC-SACs) are widely researched in various electrochemical reactions due to high metal atom utilization and catalytic activity.The catalytic activity of NC-SACs originates from the coordinating structure between single metal site(M) and the doped nitrogen(N) in carbon matrix by forming M-N_(x)-C structure(1≤x≤4).The M-N4-C structure is widely considered to be the most stable and effective catalytic site.However,there is no in-depth research for the "x" modulation in Pt-Nx-C structure and the corresponding catalytic properties.Herein,atomically dispersed Pt on N-doped carbon(Pt-NC) with Pt-Nx-C structure(1≤x≤4),as a research model,is fabricated by a ZIF-8 template and applied to catalytic oxygen reduction.Different carbonization temperatures are used to control N loss,and then modulate the N coordination of Pt-Nx-C structure.The Pt-NC has the predictable low half-wave potential(E_(1/2)) of 0.72 V vs RHE compared to the Pt/C 20% of 0.81 V due to low Pt content.Remarkably,the Pt-NC shows a high onset potential(1.10 V vs RHE,determined for j=-0.1 mA cm^(2)) and a high current density of 5.2 mA cm^(-2),more positive and higher than that of Pt/C 20%(0.96 V) and 4.9 mA cm^(-2),respectively.As the structural characterization and DFT simulation confirmed,the reducing PtN coordination number induces low valence of Pt atoms and low free energy of oxygen reduction,which is responsible for the improved catalytic activity.Furthermore,the Pt-NC shows high mass activity(172 times higher than that of Pt/C 20%),better stability and methanol crossover resistance.
基金This work was supported by the Major special projects of Science and Technology Department of Sichuan Province(No.2020ZDZX0020).
文摘Bisphenol A(BPA)has received increasing attention due to its long-term industrial application and persistence in environmental pollution.Iron-based carbon catalyst activation of peroxymonosulfate(PMS)shows a good prospect for effective elimination of recalcitrant contaminants in water.Herein,considering the problem about the leaching of iron ions and the optimization of heteroatoms doping,the iron,nitrogen and sulfur co-doped tremellalike carbon catalyst(Fe-NS@C)was rationally designed using very little iron,S-C_(3)N_(4) and low-cost chitosan(CS)via the impregnation-calcination method.The as-prepared Fe-NS@C exhibited excellent performance for complete removal of BPA(20 mg/L)by activating PMS with the high kinetic constant(1.492 min^(−1))in 15 min.Besides,the Fe-NS@C/PMS system not only possessed wide pH adaptation and high resistance to environmental interference,but also maintained an excellent degradation efficiency on different pollutants.Impressively,increased S-C_(3)N_(4) doping amount modulated the contents of different N species in Fe-NS@C,and the catalytic activity of Fe-NS@C-1-x was visibly enhanced with increasing SC_(3)N_(4) contents,verifying pyridine N and Fe-Nx as main active sites in the system.Meanwhile,thiophene sulfur(C-S-C)as active sites played an auxiliary role.Furthermore,quenching experiment,EPR analysis and electrochemical test proved that surface-bound radicals(·OH and SO_(4)^(·−))and non-radical pathways worked in the BPA degradation(the former played a dominant role).Finally,possible BPA degradation route were proposed.This work provided a promising way to synthesize the novel Fe,N and S co-doping carbon catalyst for degrading organic pollutants with low metal leaching and high catalytic ability.
