采用光学显微镜(optical microscope,OM)、扫描电子显微镜(scanning electron microscope,SEM)、透射电子显微镜(transmission electron microscope,TEM)、硬度和电导率试验仪器,研究了Cu-Ni-Fe-P合金成分设计、微观结构和性能之间的构...采用光学显微镜(optical microscope,OM)、扫描电子显微镜(scanning electron microscope,SEM)、透射电子显微镜(transmission electron microscope,TEM)、硬度和电导率试验仪器,研究了Cu-Ni-Fe-P合金成分设计、微观结构和性能之间的构效关系。结果表明,Ni/Fe质量比对合金性能具有显著调控作用,当Ni/Fe质量比为3.00时,Cu-Ni-Fe-P合金在500℃时效0.50 h条件下维氏硬度达到峰值,为171.5,此时析出相平均尺寸为2.2 nm,随着时效时间延长至12.00 h时,析出相平均尺寸增大到5.6 nm。Fe元素的添加降低了溶质原子的固溶度,有效抑制了基体晶格畸变,提高了合金导电性,当Ni/Fe质量比为1.00时,Cu-Ni-Fe-P合金电导率在500℃/12.00 h时效条件下可达峰值63.6%IACS。其中,当Ni/Fe质量比为1.00时,500℃/6.00 h时效条件下,Cu-Ni-Fe-P合金的综合性能最好。展开更多
Antibiotics are emerging pollutants that pose significant risks to environmental and human health.Periodate(PI)-based advanced oxidation processes have shown promise for their effective degradation.In this study,we sy...Antibiotics are emerging pollutants that pose significant risks to environmental and human health.Periodate(PI)-based advanced oxidation processes have shown promise for their effective degradation.In this study,we systematically investigate the structure-activity relationship of four representative Fe-based metal-organic frameworks(Fe-MOFs)-MIL-101(Fe),MIL-88B(Fe),MIL-88A(Fe),and MIL-53(Fe)-as PI activators for tetracycline(TC)degradation.Among them,MIL-101(Fe)exhibited the highest catalytic performance,owing to its unique Fe3O-OH nodes and mesoporous architecture.The MIL-101(Fe)/PI system achieved 93.3%TC degradation and 55.9%mineralization rate within 60 min.Mechanistic studies combining scavenger quenching,sulfoxide probe transformation,X-ray photoelectron spectroscopy,and X-ray absorption fine structure confirmed the generation of multiple reactive oxygen species,and high-valent Fe(IV)]O and O_(2)^(·-)played major roles in the tetracycline degradation process.Density functional theory calculations further revealed that MIL-101(Fe)and MIL-88B(Fe)effectively interact with PI to form Fe(Ⅲ)-superoxide(Fe(Ⅲ)-O-O^(·-)),a key intermediate in Fe(IV)]O generation.In contrast,the adsorption energy of MIL-53(Fe)and MIL-88A(Fe)was relatively weak,with fewer binding sites,resulting in poor performance.The synergy between Fe(Ⅲ)-O-O^(·-)formation and the pore accessibility of MIL-101(Fe)accounted for its superior catalytic efficiency.This work not only clarifies the structural factors governing PI activation in Fe-MOFs,but also proposes a mechanistically informed strategy for designing high-performance catalysts for antibiotic degradation.展开更多
The rate capability and cycling stability of sodium metal batteries taking FeS_(2) or sulfur as cathode are limited due to their low reaction kinetics and severe shuttle effect.Herein,we rationally design a novel sing...The rate capability and cycling stability of sodium metal batteries taking FeS_(2) or sulfur as cathode are limited due to their low reaction kinetics and severe shuttle effect.Herein,we rationally design a novel single-atom-dispersed S_(2)-FeNC/FeS_(2) nanocluster heterojunction embedded in carbon spheres(SFNC/FeS_(2)) for the electrode material of sodium metal batteries.Interestingly,during the discharging process,the Na^(+) is inserted into FeS_(2) to generate Na_(2)S,as well as the unique electrochemical reaction between S_(2)-FeNC and Na^(+) to form Na_(2)S.Meanwhile,the FeNC can adsorb Na_(2)S and catalyze the conversion from Na_(2)S and Fe to FeS_(2) or from Na_(2)S and FeNC to S_(2)-FeNC for suppressing the shuttle effect and promoting the distinct hybrid reversible electrochemical behavior,which improves performance tremendously.Notably,the SFNC/FeS_(2) electrode delivers a specific capacity of 338.7 mAh g^(-1) after superlong 2000 cycles at a current density of 5.0 A g^(-1) and achieves a high energy density of 430.1 Wh Kg^(-1) at a current density of 0.05 A g^(-1).This work presents a novel approach to studying sodium metal batteries with hybrid behavior for excellent high energy density and cycling stability.展开更多
基金National Natural Science Foundation of China(Nos.42177405,42377359,12075152)Energy Science and Technology discipline under the Shanghai Class IV Peak Disciplinary Development Program for the financial support.W.Y.Huang thanks the China Scholarship Council(CSC)for funding.
文摘Antibiotics are emerging pollutants that pose significant risks to environmental and human health.Periodate(PI)-based advanced oxidation processes have shown promise for their effective degradation.In this study,we systematically investigate the structure-activity relationship of four representative Fe-based metal-organic frameworks(Fe-MOFs)-MIL-101(Fe),MIL-88B(Fe),MIL-88A(Fe),and MIL-53(Fe)-as PI activators for tetracycline(TC)degradation.Among them,MIL-101(Fe)exhibited the highest catalytic performance,owing to its unique Fe3O-OH nodes and mesoporous architecture.The MIL-101(Fe)/PI system achieved 93.3%TC degradation and 55.9%mineralization rate within 60 min.Mechanistic studies combining scavenger quenching,sulfoxide probe transformation,X-ray photoelectron spectroscopy,and X-ray absorption fine structure confirmed the generation of multiple reactive oxygen species,and high-valent Fe(IV)]O and O_(2)^(·-)played major roles in the tetracycline degradation process.Density functional theory calculations further revealed that MIL-101(Fe)and MIL-88B(Fe)effectively interact with PI to form Fe(Ⅲ)-superoxide(Fe(Ⅲ)-O-O^(·-)),a key intermediate in Fe(IV)]O generation.In contrast,the adsorption energy of MIL-53(Fe)and MIL-88A(Fe)was relatively weak,with fewer binding sites,resulting in poor performance.The synergy between Fe(Ⅲ)-O-O^(·-)formation and the pore accessibility of MIL-101(Fe)accounted for its superior catalytic efficiency.This work not only clarifies the structural factors governing PI activation in Fe-MOFs,but also proposes a mechanistically informed strategy for designing high-performance catalysts for antibiotic degradation.
基金financially supported by the National Natural Science Foundation of China (No. 22579095)the Beijing-Tianjin-Hebei Basic Research Cooperation Special Project (B2024204027)+2 种基金the Youth Top-notch Talent Foundation of Hebei Provincial Universities (BJK2022023)the Natural Science Foundation of Hebei Province (B2023204006)the talent training project of Hebei province (No. B20231004)。
文摘The rate capability and cycling stability of sodium metal batteries taking FeS_(2) or sulfur as cathode are limited due to their low reaction kinetics and severe shuttle effect.Herein,we rationally design a novel single-atom-dispersed S_(2)-FeNC/FeS_(2) nanocluster heterojunction embedded in carbon spheres(SFNC/FeS_(2)) for the electrode material of sodium metal batteries.Interestingly,during the discharging process,the Na^(+) is inserted into FeS_(2) to generate Na_(2)S,as well as the unique electrochemical reaction between S_(2)-FeNC and Na^(+) to form Na_(2)S.Meanwhile,the FeNC can adsorb Na_(2)S and catalyze the conversion from Na_(2)S and Fe to FeS_(2) or from Na_(2)S and FeNC to S_(2)-FeNC for suppressing the shuttle effect and promoting the distinct hybrid reversible electrochemical behavior,which improves performance tremendously.Notably,the SFNC/FeS_(2) electrode delivers a specific capacity of 338.7 mAh g^(-1) after superlong 2000 cycles at a current density of 5.0 A g^(-1) and achieves a high energy density of 430.1 Wh Kg^(-1) at a current density of 0.05 A g^(-1).This work presents a novel approach to studying sodium metal batteries with hybrid behavior for excellent high energy density and cycling stability.
