The detrimental“shuttle effect”of lithium polysulfides(LiPSs)together with sluggish multi-order reaction kinetics are the main drawbacks hindering lithium-sulfur(Li-S)batteries from commercial success.Here,we first ...The detrimental“shuttle effect”of lithium polysulfides(LiPSs)together with sluggish multi-order reaction kinetics are the main drawbacks hindering lithium-sulfur(Li-S)batteries from commercial success.Here,we first propose the implementability of layered rare-earth hydroxides(LREHs)in Li-S batteries to optimize electrochemical performance.In this work,a two-dimensional(2D)rare-earth-based composite constructed by the layered gadolinium hydroxy chloride[Gd_(2)(OH)_(5)(H_(2)O)_(n)]Cl nanoplates(LGdH NPs)and graphene oxide(GO)was designed as a sulfur immobilizer for Li-S batteries.Combining the experimental results and density functional theory(DFT)calculations,it is revealed that the LGdH@GO composite not only provides a strong anchoring of the intermediates during cycling,but also acts as an effective catalyst to accelerate the liquid-solid conversion of polysulfides.The Li-S batteries assembled by LGdH@GO modified separators delivered a superior rate performance with a specific capacity of 605.34 mAh/g at 5 C,as well as excellent cycle stability with a decay rate of 0.087%over 500 cycles at 2 C.This study provided a deep understanding of the mechanism to suppress the“shuttle effect”by the LREHs,and a guide to design effective functional interlayers for high-performance Li-S batteries with excellent electrocatalytic activity.展开更多
We demonstrate the fabrication of a novel magnetic nanohybrid involving the drug molecule 5 aminolevulinic acid(5-ALA)intercalated Gd-Eu layered rare-earth hydroxide(LRH)coated on magnesium ferrite particles(MgFe2O4)....We demonstrate the fabrication of a novel magnetic nanohybrid involving the drug molecule 5 aminolevulinic acid(5-ALA)intercalated Gd-Eu layered rare-earth hydroxide(LRH)coated on magnesium ferrite particles(MgFe2O4).The structure,thermostability,morphology,luminescence properties,cytotoxic effect and magnetism are investigated.The 5-ALA intercalated composite may correspond to a monolayered vertical arrangement,and the thermal stability of organics is enhanced after intercalation.The LRH precursor shows red emission of Eu^3+and the maximum emission peak of the composite is at 451 nm,corresponding to the blue emission.The detection of drug molecules can be realized through the change of luminescence.The magnetic nanohybrid shows strong magnetic sensitivity,which provides an easy and efficient way to separate 5-ALA-MgFe2O4@LGd0.95H:Eu0.05 particles from a sol or a suspension system and to carry drugs to targeted locations under an external magnetic field.The cytotoxic effect of MgFe2O4@LRH is observed with a sulforhodamine B(SRB)colorimetric assay,which has low cytotoxic effects on selected cells.The fabrication of novel bifunctional drug carriers based on LRH with magnetic and fluorescent properties has potential applications in drug detection and drug delivery.展开更多
基金supported by National Science Foundation for Youths of China(Nos.22209184 and 22109163)。
文摘The detrimental“shuttle effect”of lithium polysulfides(LiPSs)together with sluggish multi-order reaction kinetics are the main drawbacks hindering lithium-sulfur(Li-S)batteries from commercial success.Here,we first propose the implementability of layered rare-earth hydroxides(LREHs)in Li-S batteries to optimize electrochemical performance.In this work,a two-dimensional(2D)rare-earth-based composite constructed by the layered gadolinium hydroxy chloride[Gd_(2)(OH)_(5)(H_(2)O)_(n)]Cl nanoplates(LGdH NPs)and graphene oxide(GO)was designed as a sulfur immobilizer for Li-S batteries.Combining the experimental results and density functional theory(DFT)calculations,it is revealed that the LGdH@GO composite not only provides a strong anchoring of the intermediates during cycling,but also acts as an effective catalyst to accelerate the liquid-solid conversion of polysulfides.The Li-S batteries assembled by LGdH@GO modified separators delivered a superior rate performance with a specific capacity of 605.34 mAh/g at 5 C,as well as excellent cycle stability with a decay rate of 0.087%over 500 cycles at 2 C.This study provided a deep understanding of the mechanism to suppress the“shuttle effect”by the LREHs,and a guide to design effective functional interlayers for high-performance Li-S batteries with excellent electrocatalytic activity.
基金supported by the Youth Top-notch Talent Training Program for Universities and Colleges under Beijing Municipality(CIT&TCD201804035)the National Natural Science Foun-dation of China(Grant No.21601016)+1 种基金the Project of Construction of Innovative Teams and Teacher Career Development for Universities and Colleges under Beiing Municipality(IDHT20180508)the Construc-tion of Scientific Research Platform(2018XK002).
文摘We demonstrate the fabrication of a novel magnetic nanohybrid involving the drug molecule 5 aminolevulinic acid(5-ALA)intercalated Gd-Eu layered rare-earth hydroxide(LRH)coated on magnesium ferrite particles(MgFe2O4).The structure,thermostability,morphology,luminescence properties,cytotoxic effect and magnetism are investigated.The 5-ALA intercalated composite may correspond to a monolayered vertical arrangement,and the thermal stability of organics is enhanced after intercalation.The LRH precursor shows red emission of Eu^3+and the maximum emission peak of the composite is at 451 nm,corresponding to the blue emission.The detection of drug molecules can be realized through the change of luminescence.The magnetic nanohybrid shows strong magnetic sensitivity,which provides an easy and efficient way to separate 5-ALA-MgFe2O4@LGd0.95H:Eu0.05 particles from a sol or a suspension system and to carry drugs to targeted locations under an external magnetic field.The cytotoxic effect of MgFe2O4@LRH is observed with a sulforhodamine B(SRB)colorimetric assay,which has low cytotoxic effects on selected cells.The fabrication of novel bifunctional drug carriers based on LRH with magnetic and fluorescent properties has potential applications in drug detection and drug delivery.
