The polysulfide shuttle limits the development of lithium-sulfur(Li-S) batteries with high energy density and long lifespan. Herein, nitrogen doped hollow carbon nanospheres(NHCS) derived from polymerization of dopami...The polysulfide shuttle limits the development of lithium-sulfur(Li-S) batteries with high energy density and long lifespan. Herein, nitrogen doped hollow carbon nanospheres(NHCS) derived from polymerization of dopamine on SiO_(2)nanospheres are employed to modify the commercial polypropylene/polyethylene/polypropylene tri-layer separators(PP/PE/PP@NHCS). The abundant nitrogen heteroatoms in NHCS exhibit strong chemical adsorption toward polysulfides, which can effectively suppress the lithium polysulfides shuttle and further enhance the utilization of active sulfur. Lithium-sulfur batteries employing the PP/PE/PP@NHCS deliver an initial discharge capacity of 1355 mAh/g and retain high capacity of 921 mAh/g after 100 cycles at 0.2 C. At a high rate of 2 C, the lithium-sulfur batteries exhibit capacity of 461 mAh/g after 1000 cycles with a capacity fading rate of 0.049% per cycle. This work demonstrates that the NHCS coated PP/PE/PP separator is promising for future commercial applications of lithium-sulfur batteries with improved electrochemical performances.展开更多
Luminescent metal organic cages(MOCs)have attracted great interest as a unique class of sensing substrates.In this work,intrinsically fluorescent Zr-MOCs were successfully used as fluorescent probes for the sensitive ...Luminescent metal organic cages(MOCs)have attracted great interest as a unique class of sensing substrates.In this work,intrinsically fluorescent Zr-MOCs were successfully used as fluorescent probes for the sensitive and selective detection of phosphate anions in water and real samples.When the ligand and Zr ion clusters form a cage,the intrinsic fluorescence of the ligand was tuned from high to weak emission due to the ligand-to-metal charge transfer(LMCT)effect,and this weakened fluorescence can be restored by the addition of phosphate.The degree of fluorescence enhancement is positively correlated with the added phosphate concentration,and the efficacy of this strategy is demonstrated by a linear phosphate detection range of 5–500µmol/L and a detection limit of 1.06µmol/L.We discuss the interaction between phosphate and Zr in scattering spectrum and MS,respectively.In comparison to phosphate adsorption on Zr-metal organic frameworks(MOFs),where phosphate connects different numbers of cages,both blocking the LMCT effect and causing the cages to aggregate.We also found that the phosphate displaces the ligand from the cage when the phosphate concentration is further expanded,resulting in the formation of new derivatives.This derivative was shown to be useful as a Lewis acid catalyst and as a rare earth ion adsorbent.展开更多
基金supported by the National Natural Science Foundation of China (Nos. U1964205, 51872303, 52172253)Zhejiang Provincial Natural Science Foundation of China (No. LD18E020004)+3 种基金Ningbo S&T Innovation 2025 Major Special Programme (Nos. 2019B10044, 20211ZDYF020077)Zhejiang Provincial Key R&D Program of China (No. 2022C01072)Chongqing Research Program of Basic Research and Frontier Technology (No. cstc2019jcyjmsxm X0510)Youth Innovation Promotion Association CAS (No. 2017342)。
文摘The polysulfide shuttle limits the development of lithium-sulfur(Li-S) batteries with high energy density and long lifespan. Herein, nitrogen doped hollow carbon nanospheres(NHCS) derived from polymerization of dopamine on SiO_(2)nanospheres are employed to modify the commercial polypropylene/polyethylene/polypropylene tri-layer separators(PP/PE/PP@NHCS). The abundant nitrogen heteroatoms in NHCS exhibit strong chemical adsorption toward polysulfides, which can effectively suppress the lithium polysulfides shuttle and further enhance the utilization of active sulfur. Lithium-sulfur batteries employing the PP/PE/PP@NHCS deliver an initial discharge capacity of 1355 mAh/g and retain high capacity of 921 mAh/g after 100 cycles at 0.2 C. At a high rate of 2 C, the lithium-sulfur batteries exhibit capacity of 461 mAh/g after 1000 cycles with a capacity fading rate of 0.049% per cycle. This work demonstrates that the NHCS coated PP/PE/PP separator is promising for future commercial applications of lithium-sulfur batteries with improved electrochemical performances.
基金the financial support from Chengdu University of Technology (No. 10912-SJGG2021-06843)
文摘Luminescent metal organic cages(MOCs)have attracted great interest as a unique class of sensing substrates.In this work,intrinsically fluorescent Zr-MOCs were successfully used as fluorescent probes for the sensitive and selective detection of phosphate anions in water and real samples.When the ligand and Zr ion clusters form a cage,the intrinsic fluorescence of the ligand was tuned from high to weak emission due to the ligand-to-metal charge transfer(LMCT)effect,and this weakened fluorescence can be restored by the addition of phosphate.The degree of fluorescence enhancement is positively correlated with the added phosphate concentration,and the efficacy of this strategy is demonstrated by a linear phosphate detection range of 5–500µmol/L and a detection limit of 1.06µmol/L.We discuss the interaction between phosphate and Zr in scattering spectrum and MS,respectively.In comparison to phosphate adsorption on Zr-metal organic frameworks(MOFs),where phosphate connects different numbers of cages,both blocking the LMCT effect and causing the cages to aggregate.We also found that the phosphate displaces the ligand from the cage when the phosphate concentration is further expanded,resulting in the formation of new derivatives.This derivative was shown to be useful as a Lewis acid catalyst and as a rare earth ion adsorbent.
