Fe2O3 has become a promising anode material in lithium-ion batteries (LIBs) in light of its low cost, high theoretical capacity (1007 mA h g^−1) and abundant reserves on the earth. Nevertheless, the practical applicat...Fe2O3 has become a promising anode material in lithium-ion batteries (LIBs) in light of its low cost, high theoretical capacity (1007 mA h g^−1) and abundant reserves on the earth. Nevertheless, the practical application of Fe2O3 as the anode material in LIBs is greatly hindered by several severe issues, such as drastic capacity falloff, short cyclic life and huge volume change during the charge/discharge process. To tackle these limitations, carbon-coated Fe2O3 (Fe2O3@MOFC) composites with a hollow sea urchin nanostructure were prepared by an effective and controllable morphology-inherited strategy. Metal-organic framework (MOF)-coated FeOOH (FeOOH@-MIL-100(Fe)) was applied as the precursor and self-sacrificial template. During annealing, the outer MOF layer protected the structure of inner Fe2O3 from collapsing and converted to a carbon coating layer in situ. When applied as anode materials in LIBs, Fe2O3@MOFC composites showed an initial discharge capacity of 1366.9 mA h g^−1 and a capacity preservation of 1551.3 mA h g^−1 after 200 cycles at a current density of 0.1 A g^−1. When increasing the current density to 1 A g^−1, a reversible and high capacity of 1208.6 mA h g^−1 was obtained. The enhanced electrochemical performance was attributed to the MOF-derived carbon coating layers and the unique hollow sea urchin nanostructures. They mitigated the effects of volume expansion, increased the lithium-ion mobility of electrode, and stabilized the as-formed solid electrolyte interphase films.展开更多
The recycling technology of photocatalyst powdery has hardly been mature in the photocatalytic oxidation so far.In this work,the hollow TiO_(2)microspheres with an appropriate thickness are confined in carbon microsph...The recycling technology of photocatalyst powdery has hardly been mature in the photocatalytic oxidation so far.In this work,the hollow TiO_(2)microspheres with an appropriate thickness are confined in carbon microspheres(CMSs)to form hollow TiO_(2)@CMSs,which are physically integrated with carbon-fiber textile by van der Waals(vdW)interactions to generate separable and recyclable hollow TiO_(2)@CMSs/carbon-fiber vdW heterostructures.Such separable and recyclable heterostructures show remarkable oxidation of 2,4-dinitrophenol.From our detailed characterization and density functional theory(DFT)calculations,we found that carbon fiber can trap electrons exerted from the excitation of hollow TiO_(2)@CMSs and creates holes in hollow TiO_(2)microspheres,which endow the carbon fiber with photocatalytic activity through coherent charge injection.This study indicates that our general strategy for the fabrication of hollow TiO_(2)@CMSs/carbon-fiber vdW heterostructures can be used as separable and recyclable photocatalyst and photoelectrocatalyst with potential industrial applications in environmentrelated fields.展开更多
High capacity Fe_(3)O_(4)-based anode materials have attracted a great deal of attention as an alternative to commercial graphite in Li-ion batteries(LIBs).However,it is still a challenge to alleviate the fast capacit...High capacity Fe_(3)O_(4)-based anode materials have attracted a great deal of attention as an alternative to commercial graphite in Li-ion batteries(LIBs).However,it is still a challenge to alleviate the fast capacity fading of Fe_(3)O_(4) due to the intercalation of Lit.In this work,we develop a novel and effective strategy to rapidly fabricate the hollow Fe_(3)O_(4) nanostructures via the solvent-induced effect.The influence of the ratio of the tert-butanol(TB)and the water on the microstructure was further discussed.As expected,when the hollow nanostructures based on the 1:1 ratio of TB and water is used as the anode material for LIBs,a high reversible capacity of 1020 mA h g^(-1) after 100 cycles at 1 A g^(-1) and 450 mA h g^(-1) even for 5 A g^(-1) after 1000 cycles can be obtained,paving a new avenue to fabricate the functionally hollow nanostructures for high-performance anode materials or other applications.展开更多
基金financially supported by the National Key R&D Program of China (2017YFA0403402 and 2019YFA0405601)the National Natural Science Foundation of China(21773222,U1732272 and U1932214)the DNL Cooperation Fund,and Chinese Academy of Sciences (DNL180201)
文摘Fe2O3 has become a promising anode material in lithium-ion batteries (LIBs) in light of its low cost, high theoretical capacity (1007 mA h g^−1) and abundant reserves on the earth. Nevertheless, the practical application of Fe2O3 as the anode material in LIBs is greatly hindered by several severe issues, such as drastic capacity falloff, short cyclic life and huge volume change during the charge/discharge process. To tackle these limitations, carbon-coated Fe2O3 (Fe2O3@MOFC) composites with a hollow sea urchin nanostructure were prepared by an effective and controllable morphology-inherited strategy. Metal-organic framework (MOF)-coated FeOOH (FeOOH@-MIL-100(Fe)) was applied as the precursor and self-sacrificial template. During annealing, the outer MOF layer protected the structure of inner Fe2O3 from collapsing and converted to a carbon coating layer in situ. When applied as anode materials in LIBs, Fe2O3@MOFC composites showed an initial discharge capacity of 1366.9 mA h g^−1 and a capacity preservation of 1551.3 mA h g^−1 after 200 cycles at a current density of 0.1 A g^−1. When increasing the current density to 1 A g^−1, a reversible and high capacity of 1208.6 mA h g^−1 was obtained. The enhanced electrochemical performance was attributed to the MOF-derived carbon coating layers and the unique hollow sea urchin nanostructures. They mitigated the effects of volume expansion, increased the lithium-ion mobility of electrode, and stabilized the as-formed solid electrolyte interphase films.
基金financial support from the National Natural Science Foundation of China(Grant No.:51464020)
文摘The recycling technology of photocatalyst powdery has hardly been mature in the photocatalytic oxidation so far.In this work,the hollow TiO_(2)microspheres with an appropriate thickness are confined in carbon microspheres(CMSs)to form hollow TiO_(2)@CMSs,which are physically integrated with carbon-fiber textile by van der Waals(vdW)interactions to generate separable and recyclable hollow TiO_(2)@CMSs/carbon-fiber vdW heterostructures.Such separable and recyclable heterostructures show remarkable oxidation of 2,4-dinitrophenol.From our detailed characterization and density functional theory(DFT)calculations,we found that carbon fiber can trap electrons exerted from the excitation of hollow TiO_(2)@CMSs and creates holes in hollow TiO_(2)microspheres,which endow the carbon fiber with photocatalytic activity through coherent charge injection.This study indicates that our general strategy for the fabrication of hollow TiO_(2)@CMSs/carbon-fiber vdW heterostructures can be used as separable and recyclable photocatalyst and photoelectrocatalyst with potential industrial applications in environmentrelated fields.
基金financially supported by the National Natural Science Foundation of China(Grant no.51673154,51173139,51503159).
文摘High capacity Fe_(3)O_(4)-based anode materials have attracted a great deal of attention as an alternative to commercial graphite in Li-ion batteries(LIBs).However,it is still a challenge to alleviate the fast capacity fading of Fe_(3)O_(4) due to the intercalation of Lit.In this work,we develop a novel and effective strategy to rapidly fabricate the hollow Fe_(3)O_(4) nanostructures via the solvent-induced effect.The influence of the ratio of the tert-butanol(TB)and the water on the microstructure was further discussed.As expected,when the hollow nanostructures based on the 1:1 ratio of TB and water is used as the anode material for LIBs,a high reversible capacity of 1020 mA h g^(-1) after 100 cycles at 1 A g^(-1) and 450 mA h g^(-1) even for 5 A g^(-1) after 1000 cycles can be obtained,paving a new avenue to fabricate the functionally hollow nanostructures for high-performance anode materials or other applications.
基金supported by the National Natural Science Foundation of China (21601137)the Natural Science Foundation of Zhejiang Province (LQ16B010003)the Basic Science and Technology Research Project of Wenzhou, Zhejiang Province (G20190007)。
