In this work,we prepared a material with magnetic nanoparticles(Fe_(3)O_(4))as core,layered double hydroxides(LDHs)as affinity shell,and cerium dioxide(CeO_(2))as functional molecules(denoted as Fe_(3)O_(4)@LDH-CeO_(2...In this work,we prepared a material with magnetic nanoparticles(Fe_(3)O_(4))as core,layered double hydroxides(LDHs)as affinity shell,and cerium dioxide(CeO_(2))as functional molecules(denoted as Fe_(3)O_(4)@LDH-CeO_(2)).On the basis of combined immobilized metal ion affinity chromatography(IMAC)and metal oxide affinity chromatography(MOAC),Fe_(3)O_(4)@LDH-CeO_(2) was used to enrich phosphopeptides with high efficiency.The material exhibited high selectivity(α-casein:β-casein:BSA=1:1:5000,mass ratio),high recovery(95.87%),and good reusability of 10 times adsorption-desorption experiments.The feasibility of Fe_(3)O_(4)@LDH-CeO_(2) was further investigated by extracting phosphopeptides from biological samples(nonfat milk,serum,saliva,and A549 cell lysate).展开更多
Flexible aqueous Ni//Zn batteries have attracted much attention as promising candidates for energy storage in the field of flexible electronics.However,the Ni-based cathodes still face the challenges of poor conductiv...Flexible aqueous Ni//Zn batteries have attracted much attention as promising candidates for energy storage in the field of flexible electronics.However,the Ni-based cathodes still face the challenges of poor conductivity,confined charge/mass transfer,and non-flexibility.In this work,we designed a hollow tubular structure consisting of a conductive silver nanowire (Ag NW) wrapped by active Ni Co layered double hydroxide (LDH),for enhancing the electrical conductivity,improving the charge/mass transfer kinetics,and facilitating the ion penetration.By optimizing the contents of Ni,Co and Ag NW,the Ni_(4)Co LDH@Ag_(1.5)NW composite shows a maximum specific capacity of 115.83 m Ah g^(-1)at 0.1 A g^(-1)measured in a two-electrode system.Highlightingly,the flexible aqueous Ni//Zn battery assembled by Ni_(4)Co LDH@Ag_(1.5)NW interwoven with multi-walled carbon nanotube cathode and Zn foil anode realizes a high power density of 160μW cm^(-2)at the energy density of 23.14μWh cm^(-2),which is superior compared with those of oxide/hydroxide based devices and even higher than those of many carbon-based supercapacitors,showing its promising potentials for flexible energy storage applications.展开更多
Using magnetic layered double hydroxide （MLDH） as carrier of fluorescein （FLU）, a fluorescent composite of MLDH-FLU was prepared via intercalation reaction of ion change. The crystal properties of MLDH-FLU were in...Using magnetic layered double hydroxide （MLDH） as carrier of fluorescein （FLU）, a fluorescent composite of MLDH-FLU was prepared via intercalation reaction of ion change. The crystal properties of MLDH-FLU were investigated through XRD, IR, TEM and TG-DSC characterization. It is shown that the crystal type of MLDH-FLU composite matched well with R-hexagonal crystal system of MLDH, with crystal cell parameters of a, c and channel height h equal to 0.3199, 2.411 and 0.3267 nm respectively. The superabundant pigment adsorbed outside the composite should be cleared before interference with cells, but excessive wash would decrease stability and cause crystal phase transformation of MLDH.展开更多
Novel magnetic Fe3O4@C@MgAl-layerecl double-hydroxide（LDH） nanoparticles have been successfully prepared by the chemical self-assembly methods.The properties of surface functional groups,crystal structure,magnetism ...Novel magnetic Fe3O4@C@MgAl-layerecl double-hydroxide（LDH） nanoparticles have been successfully prepared by the chemical self-assembly methods.The properties of surface functional groups,crystal structure,magnetism and surface morphology of magnetic nanoparticles were characterized by Fourier transform infrared spectroscopy（FT-IR）,X-ray diffraction（XRD）,thermal gravity-differential thermal gravity（TG-DTG）,scanning electron microscopy（SEM）,and transmission electron microscopy（TEM）.The adsorption studies of the novel adsorbent in removing heavy metals Cr（Ⅵ） from waste water showed that the maximum absorption amount of Cr（Ⅵ） was 152.0 mg/g at 40℃ and pH 6.0.The excellent adsorption capacity of the Fe3O4@C@MgAl-LDH nano-absorbents plus their easy separation,environmentally friendly composition and reusability makes them more suitable adsorbents for the removal of metal ions from waste water.展开更多
Cobalt ferrite CoxNi1-xFe2O4 （x = 0, 0.5, 1 ） particles with controllable magnetic properties have been prepared by calcination of co-substituted NiFe^2＋Fe^3＋ -layered double hydroxide （NiFe^2＋Fe^3＋-LDH） precu...Cobalt ferrite CoxNi1-xFe2O4 （x = 0, 0.5, 1 ） particles with controllable magnetic properties have been prepared by calcination of co-substituted NiFe^2＋Fe^3＋ -layered double hydroxide （NiFe^2＋Fe^3＋-LDH） precursors prepared via a scalable method involving separate nucleation and aging steps （SNAS）. Their structural and magnetic characteristics were investigated by powder X-ray diffraction （XRD）, scanning electron microscopy （SEM） and vibrating sample magnetometry （VSM）. Measurements of magnetic properties show that the saturation magnetization （Ms） and coercivity （He） of the calcined products increased with increasing cobalt content. The LDH precursor-based product obtained by calcination of a mixture of CoFe^2＋Fe3^＋-LDH and NiFe^2＋Fe^3＋ -LDH powders with a Co/Ni molar ratio of 1：1, exhibits a moderate value of Ms and an increased value of He compared to the corresponding values for an Ni0.5Co0.5Fe2O4 material prepared by calcination of a Co0.5Ni0.5Fe^2＋Fe^3＋-LDH precursor, and a physical mixture of CoFe2O4 and NiFe2O4 with a Co/Ni molar ratio of 1 ： 1. These results may provide a way to regulate magnetic anisotropy of ferrite spinels by varying the composition of the LDH precursors.展开更多
NiFe_(2)O_(4) nanoparticles(<10 nm)embedded in a NiO matrix have been fabricated by calcining the corresponding Ni^(Ⅱ)Fe^(Ⅲ)-layered double hydroxide(LDH)precursors at high temperature(500℃).Compared with the Ni...NiFe_(2)O_(4) nanoparticles(<10 nm)embedded in a NiO matrix have been fabricated by calcining the corresponding Ni^(Ⅱ)Fe^(Ⅲ)-layered double hydroxide(LDH)precursors at high temperature(500℃).Compared with the NiFe_(2)O_(4)/NiO nanocomposite obtained by calcination of a precursor prepared by a traditional chemical coprecipitation method,those derived from NiFe-LDH precursors show much higher blocking temperatures(TB)(~380 K).The enhanced magnetic stability can be ascribed to the much stronger interfacial interaction between NiFe_(2)O_(4) and NiO phases due to the topotactic nature of the transformation of the LDH precursor to the NiFe_(2)O_(4)/NiO composite material.Through tuning the Ni^(Ⅱ)/Fe^(Ⅲ) molar ratio of the NiFe-LDH precursor,the NiFe_(2)O_(4) concentration can be precisely controlled,and the TB value as well as the magnetic properties of the final material can also be regulated.This work represents a successful example of the fabrication of ferro(ferri)magnetic(FM)/antiferrimagnetic(AFM)systems with high magnetic stability from LDH precursors.This method is general and may be readily extended to other FM/AFM systems due to the wide range of available LDH precursors.展开更多
The magnetic composite-materials(Fe3O4@SDBS@LDHs)were prepared by sodium dodecyl benzene sulfonate(SDBS)modified layered double hydroxides(SDBS@LDHs)with Fe3O4via co-precipitation method.The results of XRD,FT-IR and S...The magnetic composite-materials(Fe3O4@SDBS@LDHs)were prepared by sodium dodecyl benzene sulfonate(SDBS)modified layered double hydroxides(SDBS@LDHs)with Fe3O4via co-precipitation method.The results of XRD,FT-IR and SEM/EDS indicated that the dispersibility of LDHs was improved,and the modification of SDBS took place on the surface of LDHs.The adsorption capacity of Fe3O4@SDBS@LDHs to brilliant green(BG)reaches329.1mg/g after the adsorption equilibrium.The thermodynamic parameters indicated that the adsorption process was endothermic and spontaneous,and the rate of a reaction increased with the raise of the reaction temperature.The Langmuir model was applicable for describing the sorption isotherms,indicating that the adsorption process is a monolayer adsorption.The results of kinetics study showed that adsorption fitted the pseudo-second order model well.The adsorbents still have good adsorption performance after four adsorption cycles.Moreover,the magnetic composite could be easily separated from aqueous solution.This indicated that Fe3O4@SDBS@LDHs can be considered as potential adsorbents in environmental applications for the removal of BG from aqueous solutions.展开更多
A density functional theory （DFT） study has been carried out for [Zn-1AI（OH2）n＋6（OH）2n-2]^3＋ （n=3-6） and [Znn-1AI（OH2）2n-2（OH）2n-2]^3＋ （n = 7） clusters, which include the basic structural information ...A density functional theory （DFT） study has been carried out for [Zn-1AI（OH2）n＋6（OH）2n-2]^3＋ （n=3-6） and [Znn-1AI（OH2）2n-2（OH）2n-2]^3＋ （n = 7） clusters, which include the basic structural information of the brucite-like lattice structure of Zn/Al layered double hydroxides （LDHs） with Zn/AI molar ratio （R） in the range 2-6, in order to understand the effect of the Zn/Al ratio on the structure and stability of binary Zn/Al LDHs. Based on systematic calculations of the geometric parameters and formation energies of the cluster models, it was found that it is possible for Zn^2＋ and Al^3＋ cations to replace Mg^2＋ isomorphously in the brucite-like structure with different R values, resulting in differences in microstructure of the clusters and unit cell parameter a of the Zn/Al LDHs. Analysis of the geometry and bonding around the trivalent Al^3＋ or divalent Zn^2＋ cations reveals that Al^3＋ plays a more significant role than Zn^2＋ in determining the microstructure properties, formation and bonding stability of the corresponding ZnRAl clusters when R〈5, while the influence of Zn^2＋ becomes the dominant factor in the case of R〉 5. These findings are in good agreement with experiments. This work provides a detailed electronic-level understanding of how the composition of cations affects the microstructure and stability of Zn-containing binary LDH layers.展开更多
利用化学共沉淀法制备纳米Mn-Zn铁氧体磁流体,再以一定比例将其掺入水泥浆体制备吸波层,以膨胀珍珠岩作为匹配层,制备双层水泥基吸波材料,研究了不同纳米组分掺入量对该种水泥基材料吸波性能的影响。结果表明:纳米Mn-Zn铁氧体吸波砂浆...利用化学共沉淀法制备纳米Mn-Zn铁氧体磁流体,再以一定比例将其掺入水泥浆体制备吸波层,以膨胀珍珠岩作为匹配层,制备双层水泥基吸波材料,研究了不同纳米组分掺入量对该种水泥基材料吸波性能的影响。结果表明:纳米Mn-Zn铁氧体吸波砂浆在厚度(20+10)mm、掺量7%时,在8~18 GHz频段内反射率都小于-10 d B,最小反射率为18 GHz处的-15.1 d B。展开更多
基金National Natural Science Foundation of China(Nos.22004073 and 21961024)Natural Science Foundation of Inner Mongolia,China(No.2020BS02010)+2 种基金Talent Research Support Funds from Government-Sponsored Institution of Inner Mongolia,China(No.RCQD19002)Inner Mongolia Minzu University Doctoral Research Startup Fund Project,China(No.BS516)Incentive Funding from Nano Innovation Institute(NII)of Inner Mongolia Minzu University,China.
文摘In this work,we prepared a material with magnetic nanoparticles(Fe_(3)O_(4))as core,layered double hydroxides(LDHs)as affinity shell,and cerium dioxide(CeO_(2))as functional molecules(denoted as Fe_(3)O_(4)@LDH-CeO_(2)).On the basis of combined immobilized metal ion affinity chromatography(IMAC)and metal oxide affinity chromatography(MOAC),Fe_(3)O_(4)@LDH-CeO_(2) was used to enrich phosphopeptides with high efficiency.The material exhibited high selectivity(α-casein:β-casein:BSA=1:1:5000,mass ratio),high recovery(95.87%),and good reusability of 10 times adsorption-desorption experiments.The feasibility of Fe_(3)O_(4)@LDH-CeO_(2) was further investigated by extracting phosphopeptides from biological samples(nonfat milk,serum,saliva,and A549 cell lysate).
基金sponsored by the National Natural Science Foundation of China(61804054)the Natural Science Foundation of Shanghai(18ZR1410400)+2 种基金the Shanghai Sailing Program(17YF1403300)the Shanghai Aerospace Science and Technology Innovation Fundation(SISP2018)the Shanghai Aerospace Science and Technology Innovation Fund(SAST2019-067)。
文摘Flexible aqueous Ni//Zn batteries have attracted much attention as promising candidates for energy storage in the field of flexible electronics.However,the Ni-based cathodes still face the challenges of poor conductivity,confined charge/mass transfer,and non-flexibility.In this work,we designed a hollow tubular structure consisting of a conductive silver nanowire (Ag NW) wrapped by active Ni Co layered double hydroxide (LDH),for enhancing the electrical conductivity,improving the charge/mass transfer kinetics,and facilitating the ion penetration.By optimizing the contents of Ni,Co and Ag NW,the Ni_(4)Co LDH@Ag_(1.5)NW composite shows a maximum specific capacity of 115.83 m Ah g^(-1)at 0.1 A g^(-1)measured in a two-electrode system.Highlightingly,the flexible aqueous Ni//Zn battery assembled by Ni_(4)Co LDH@Ag_(1.5)NW interwoven with multi-walled carbon nanotube cathode and Zn foil anode realizes a high power density of 160μW cm^(-2)at the energy density of 23.14μWh cm^(-2),which is superior compared with those of oxide/hydroxide based devices and even higher than those of many carbon-based supercapacitors,showing its promising potentials for flexible energy storage applications.
基金supported by the National Natural Science Foundation of China(Nos.81260483,20961008)
文摘Using magnetic layered double hydroxide （MLDH） as carrier of fluorescein （FLU）, a fluorescent composite of MLDH-FLU was prepared via intercalation reaction of ion change. The crystal properties of MLDH-FLU were investigated through XRD, IR, TEM and TG-DSC characterization. It is shown that the crystal type of MLDH-FLU composite matched well with R-hexagonal crystal system of MLDH, with crystal cell parameters of a, c and channel height h equal to 0.3199, 2.411 and 0.3267 nm respectively. The superabundant pigment adsorbed outside the composite should be cleared before interference with cells, but excessive wash would decrease stability and cause crystal phase transformation of MLDH.
基金supported by Scientific Research Starting Project of SWPU(No.2014QH013)Open Fund of state key laboratory of Oil & Gas reservoir geology and exploitation(No.PLN1126)major cultivation project of Sichuan Provincial Department of Education Science and Technology Achievement Transformation(No. 14CZ0005)
文摘Novel magnetic Fe3O4@C@MgAl-layerecl double-hydroxide（LDH） nanoparticles have been successfully prepared by the chemical self-assembly methods.The properties of surface functional groups,crystal structure,magnetism and surface morphology of magnetic nanoparticles were characterized by Fourier transform infrared spectroscopy（FT-IR）,X-ray diffraction（XRD）,thermal gravity-differential thermal gravity（TG-DTG）,scanning electron microscopy（SEM）,and transmission electron microscopy（TEM）.The adsorption studies of the novel adsorbent in removing heavy metals Cr（Ⅵ） from waste water showed that the maximum absorption amount of Cr（Ⅵ） was 152.0 mg/g at 40℃ and pH 6.0.The excellent adsorption capacity of the Fe3O4@C@MgAl-LDH nano-absorbents plus their easy separation,environmentally friendly composition and reusability makes them more suitable adsorbents for the removal of metal ions from waste water.
基金supported by the National Natural Science Foundation of China, the 111 Project (B07004)the Program for New Century Excellent Talents in Universities, the Beijing Nova Program (2007B021)the Natural Science Foundation for Young Teachers of Beijing University of Chemical Technology
文摘Cobalt ferrite CoxNi1-xFe2O4 （x = 0, 0.5, 1 ） particles with controllable magnetic properties have been prepared by calcination of co-substituted NiFe^2＋Fe^3＋ -layered double hydroxide （NiFe^2＋Fe^3＋-LDH） precursors prepared via a scalable method involving separate nucleation and aging steps （SNAS）. Their structural and magnetic characteristics were investigated by powder X-ray diffraction （XRD）, scanning electron microscopy （SEM） and vibrating sample magnetometry （VSM）. Measurements of magnetic properties show that the saturation magnetization （Ms） and coercivity （He） of the calcined products increased with increasing cobalt content. The LDH precursor-based product obtained by calcination of a mixture of CoFe^2＋Fe3^＋-LDH and NiFe^2＋Fe^3＋ -LDH powders with a Co/Ni molar ratio of 1：1, exhibits a moderate value of Ms and an increased value of He compared to the corresponding values for an Ni0.5Co0.5Fe2O4 material prepared by calcination of a Co0.5Ni0.5Fe^2＋Fe^3＋-LDH precursor, and a physical mixture of CoFe2O4 and NiFe2O4 with a Co/Ni molar ratio of 1 ： 1. These results may provide a way to regulate magnetic anisotropy of ferrite spinels by varying the composition of the LDH precursors.
基金This work was supported by the National Natural Science Foundation of China,the 111 Project(No.B07004)the 973 Program(No.2009CB939802)+1 种基金the Program for New Century Excellent Talents in Universities(No.NCET-07-0055)the Beijing Nova Program(No.2007B021).
文摘NiFe_(2)O_(4) nanoparticles(<10 nm)embedded in a NiO matrix have been fabricated by calcining the corresponding Ni^(Ⅱ)Fe^(Ⅲ)-layered double hydroxide(LDH)precursors at high temperature(500℃).Compared with the NiFe_(2)O_(4)/NiO nanocomposite obtained by calcination of a precursor prepared by a traditional chemical coprecipitation method,those derived from NiFe-LDH precursors show much higher blocking temperatures(TB)(~380 K).The enhanced magnetic stability can be ascribed to the much stronger interfacial interaction between NiFe_(2)O_(4) and NiO phases due to the topotactic nature of the transformation of the LDH precursor to the NiFe_(2)O_(4)/NiO composite material.Through tuning the Ni^(Ⅱ)/Fe^(Ⅲ) molar ratio of the NiFe-LDH precursor,the NiFe_(2)O_(4) concentration can be precisely controlled,and the TB value as well as the magnetic properties of the final material can also be regulated.This work represents a successful example of the fabrication of ferro(ferri)magnetic(FM)/antiferrimagnetic(AFM)systems with high magnetic stability from LDH precursors.This method is general and may be readily extended to other FM/AFM systems due to the wide range of available LDH precursors.
基金Project(21476269)supported by the National Natural Science Foundation of China
文摘The magnetic composite-materials(Fe3O4@SDBS@LDHs)were prepared by sodium dodecyl benzene sulfonate(SDBS)modified layered double hydroxides(SDBS@LDHs)with Fe3O4via co-precipitation method.The results of XRD,FT-IR and SEM/EDS indicated that the dispersibility of LDHs was improved,and the modification of SDBS took place on the surface of LDHs.The adsorption capacity of Fe3O4@SDBS@LDHs to brilliant green(BG)reaches329.1mg/g after the adsorption equilibrium.The thermodynamic parameters indicated that the adsorption process was endothermic and spontaneous,and the rate of a reaction increased with the raise of the reaction temperature.The Langmuir model was applicable for describing the sorption isotherms,indicating that the adsorption process is a monolayer adsorption.The results of kinetics study showed that adsorption fitted the pseudo-second order model well.The adsorbents still have good adsorption performance after four adsorption cycles.Moreover,the magnetic composite could be easily separated from aqueous solution.This indicated that Fe3O4@SDBS@LDHs can be considered as potential adsorbents in environmental applications for the removal of BG from aqueous solutions.
基金supported by the National Natural Science Foundation of China and the Program for Changjiang Scholars and Innovative Research Teams in Universities (Grant No.IRT0406)
文摘A density functional theory （DFT） study has been carried out for [Zn-1AI（OH2）n＋6（OH）2n-2]^3＋ （n=3-6） and [Znn-1AI（OH2）2n-2（OH）2n-2]^3＋ （n = 7） clusters, which include the basic structural information of the brucite-like lattice structure of Zn/Al layered double hydroxides （LDHs） with Zn/AI molar ratio （R） in the range 2-6, in order to understand the effect of the Zn/Al ratio on the structure and stability of binary Zn/Al LDHs. Based on systematic calculations of the geometric parameters and formation energies of the cluster models, it was found that it is possible for Zn^2＋ and Al^3＋ cations to replace Mg^2＋ isomorphously in the brucite-like structure with different R values, resulting in differences in microstructure of the clusters and unit cell parameter a of the Zn/Al LDHs. Analysis of the geometry and bonding around the trivalent Al^3＋ or divalent Zn^2＋ cations reveals that Al^3＋ plays a more significant role than Zn^2＋ in determining the microstructure properties, formation and bonding stability of the corresponding ZnRAl clusters when R〈5, while the influence of Zn^2＋ becomes the dominant factor in the case of R〉 5. These findings are in good agreement with experiments. This work provides a detailed electronic-level understanding of how the composition of cations affects the microstructure and stability of Zn-containing binary LDH layers.
文摘利用化学共沉淀法制备纳米Mn-Zn铁氧体磁流体,再以一定比例将其掺入水泥浆体制备吸波层,以膨胀珍珠岩作为匹配层,制备双层水泥基吸波材料,研究了不同纳米组分掺入量对该种水泥基材料吸波性能的影响。结果表明:纳米Mn-Zn铁氧体吸波砂浆在厚度(20+10)mm、掺量7%时,在8~18 GHz频段内反射率都小于-10 d B,最小反射率为18 GHz处的-15.1 d B。
