The microstructures and thermodynamic properties of mixed systems comprising pyridinium ionic liquid[HPy][BF_(4)]and acetonitrile at different mole fractions were studied using molecular dynamics simulation in this wo...The microstructures and thermodynamic properties of mixed systems comprising pyridinium ionic liquid[HPy][BF_(4)]and acetonitrile at different mole fractions were studied using molecular dynamics simulation in this work.The following properties were determined:density,self-diffusion coefficient,excess molar volume,and radial distribution function.The results show that with an increase in the mole fraction of[HPy][BF_(4)],the self-diffusion coefficient decreases.Additionally,the excess molar volume initially decreases,reaches a minimum,and then increases.The rules of radial distribution functions(RDFs)of characteristic atoms are different.With increasing the mole fraction of[HPy][BF_(4)],the first peak of the RDFs of HA1-F decreases,while that of CT6-CT6 rises at first and then decreases.This indicates that the solvent molecules affect the polar and non-polar regions of[HPy][BF_(4)]differently.展开更多
A composite solid electrolyte comprising a Cu-Al bimetallic metal-organic framework(CAB),lithium salt(LiTFSI)and polyethylene oxide(PEO)was fabricated through molecular grafting to enhance the ionic conductivity of th...A composite solid electrolyte comprising a Cu-Al bimetallic metal-organic framework(CAB),lithium salt(LiTFSI)and polyethylene oxide(PEO)was fabricated through molecular grafting to enhance the ionic conductivity of the PEO-based electrolytes.Experimental and molecular dynamics simulation results indicated that the electrolyte with 10 wt.%CAB(PL-CAB-10%)exhibits high ionic conductivity(8.42×10~(-4)S/cm at 60℃),high Li+transference number(0.46),wide electrochemical window(4.91 V),good thermal stability,and outstanding mechanical properties.Furthermore,PL-CAB-10%exhibits excellent cycle stability in both Li-Li symmetric battery and Li/PL-CAB-10%/LiFePO4 asymmetric battery setups.These enhanced performances are primarily attributable to the introduction of the versatile CAB.The abundant metal sites in CAB can react with TFSI~-and PEO through Lewis acid-base interactions,promoting LiTFSI dissociation and improving ionic conductivity.Additionally,regular pores in CAB provide uniformly distributed sites for cation plating during cycling.展开更多
Thispaper has investigated the coordination and supramolecular assemblies of alkali metal ions,cucurbit[5]uril(Q[5]),and[CdCl_(4)]^(2-)to confirm whether[CdCl_(4)]^(2-)can produce the“honeycomb effect”,induce coordi...Thispaper has investigated the coordination and supramolecular assemblies of alkali metal ions,cucurbit[5]uril(Q[5]),and[CdCl_(4)]^(2-)to confirm whether[CdCl_(4)]^(2-)can produce the“honeycomb effect”,induce coordination of alkali metal ions to Q[5],and form linear coordination polymers.In this work,the effect of alkali metal ions on the construction of Q[5]-Cd^(2+)ion system under acidic conditions was investigated.Five complexes were successfully obtained by solvent evaporation method.Among the five crystal structures obtained,it can be observed that the presence of[CdCl_(4)]^(2-)did not result in the complexation of alkali metal ions by the Q[5]molecule.Instead,a bowl-like Cd^(2+)@Q[5]complex was formed.Indeed,[CdCl_(4)]^(2-)did not produce the honeycomb effect but led to the formation of Q[5]-based honeycomb frameworks with hexagonal cellsoccupied by[CdCl_(4)]^(2-).The experimental results show that cadmium ion showed stronger ability to coordinate to Q[5]in HCl solution.展开更多
Rod-shaped PbW O4 microcrystals of length 1 μm were fabricated by a hydrothermal route and subsequent calcination. Pt nanoparticles（NPs） of different contents（0.5 wt%,1 wt% and 2 wt%） were subsequently deposited ...Rod-shaped PbW O4 microcrystals of length 1 μm were fabricated by a hydrothermal route and subsequent calcination. Pt nanoparticles（NPs） of different contents（0.5 wt%,1 wt% and 2 wt%） were subsequently deposited on the PbW O4 microcrystals,producing robust Pt/PbW O4 composite microcrystals. The PbW O4 microcrystals and Pt/PbW O4 photocatalysts were characterized by X-ray diffraction,N2 sorption measurements,scanning electron microscopy,transmission electron microscopy,and X-ray photoelectron,photoluminescence,Fourier-transform infrared,and ultraviolet-visible diffuse reflectance spectroscopies. The photocatalytic performances of the catalysts were evaluated by the consecutive photocatalytic degradation of acid orange II dye. The Pt/PbW O4 composite microcrystals exhibited high photocatalytic activity and stability. The deposition of Pt NPs produced surface plasmon resonance（SPR）,which induced a large visible light absorption. A Pt NP content of 1-2 wt% resulted in an ~2 times increase in photocatalytic activity,compared with the activity of Pt/PbW O4. The crystal structure and high crystallinity of PbW O4 resulted in its favorable photocatalytic property,and the SPR effect of the Pt NPs promoted visible light harvesting. The Pt NPs also enhanced the separation of photo-generated electrons and holes,which further promoted the photocatalytic reaction.展开更多
A new anion receptor bearing phenolic hydroxy group based on 3,5- ditertbutylsalicylaldehyde-p-nitrophenylhydrazone （1） was designed and synthesized. Upon addition of AcO- and F-, the receptor exhibited visible colo...A new anion receptor bearing phenolic hydroxy group based on 3,5- ditertbutylsalicylaldehyde-p-nitrophenylhydrazone （1） was designed and synthesized. Upon addition of AcO- and F-, the receptor exhibited visible color changes from deep yellow to purple. However, no obvious color changes were observed on addition of the other anions tested （H2PO4-, Cl-, Br-, I-）. The binding properties of the receptor with anions such as AcO and F- were investigated by UV-Vis and fluorescent titrations. The result indicated that the receptor 1 had a higher affinity to AcO- and F- and a 1：1 host-guest complex was formed through H-bond interactions between 1 and anions.展开更多
Spectrum analysis of the plasma has over the years been growing both in methods and instrument, which makes it become a widely used non-contact detection method, without disturbing the arc plasma itself. With noticeab...Spectrum analysis of the plasma has over the years been growing both in methods and instrument, which makes it become a widely used non-contact detection method, without disturbing the arc plasma itself. With noticeable developments in the industry application of the method, a need for careful analysis of the plasma with both time and space identification is desirable. Therefore, a spectral measurement system is developed in this paper for diagnosing arc plasma with time and space identification. With a new hollow probe scanning method, the instrument can be used to provide information like energy distribution of plasma, temperature within the arc plasma, which are of great significance with the requirement of space identification. Furthermore, the system can also be used to capture the instant state of the arc plasma with the synchronic triggering system, which uses high speed photo and electrical signal as the time criterion. The industry applications prove that the system works well for online detection of the arc plasma.展开更多
A novel solvent extraction process for extraction and separation of copper from other base metal ions using a bifunctional ionic liquid (IL) (trioctylmethylammonium/2,4,4-trimethylpentyl phosphinate, [A336/Cy272]) in ...A novel solvent extraction process for extraction and separation of copper from other base metal ions using a bifunctional ionic liquid (IL) (trioctylmethylammonium/2,4,4-trimethylpentyl phosphinate, [A336/Cy272]) in kerosene was reported. This IL was found to extract copper more efficiently than the individual extractants Aliquat 336 or Cyanex 272. Formation of an octahedral copper-IL complex was characterized by UV-Visible spectra and metal ligand interaction was confirmed by FTIR spectra. The loading capacity of 0.1 mol/L [A336/Cy272] was found to be 1.71 g/L. Stripping studies reported that 0.298 g/L copper ions were efficiently stripped using 0.1 mol/L sulfuric acid from 0.05 mol/L loaded IL. The selectivity of copper against nickel, cadmium and iron was investigated from their equimolar binary mixtures using 0.05 mol/L [A336/Cy272] in kerosene. The highest separation factorβCu/Cd=8.41 was obtained at pH 3.56. Copper can be effectively separated from nickel over the pH range studied. The IL extracts preferentially iron over copper and the highest separation factorβFe/Cuwas 3246 at pH 2.4. The extraction rate of metal ions from a synthetic solution containing copper with other metal impurities was in the order of Fe>Zn>Cu>Cd>Co>Ni.展开更多
Nitrogen and phosphorus co-doped graphene quantum dot-modified Bi5O7 I(NPG/Bi5O7 I)nanorods were fabricated via a simple solvothermal method.The morphology,structure,and optical properties of the as-prepared samples w...Nitrogen and phosphorus co-doped graphene quantum dot-modified Bi5O7 I(NPG/Bi5O7 I)nanorods were fabricated via a simple solvothermal method.The morphology,structure,and optical properties of the as-prepared samples were investigated by X-ray diffraction,scanning electron microscopy,high-resolution transmission electron microscopy,X-ray photoelectron spectroscopy(XPS),and diffused reflectance spectroscopy.The photocatalytic performance was estimated by degrading the broad-spectrum antibiotics tetracycline and enrofloxacin under visible light irradiation.The photodegradation activity of Bi5O7 I improved after its surface was modified with NPGs,which was attributed to an increase in the photogenerated charge transport rate and a decrease in the electron-hole pair recombination efficiency.From the electron spin resonance spectra,XPS valence band data,and free radical trapping experiment results,the main active substances involved in the photocatalytic degradation process were determined to be photogenerated holes and superoxide radicals.A possible photocatalytic degradation mechanism for NPG/Bi5O7 I nanorods was proposed.展开更多
In this work grand canonical Monte Carlo simulations were performed to study gas separation in three pairs of isoreticular metal-organic frameworks (IRMOFs) with and without catenation at room temperature.Mixture comp...In this work grand canonical Monte Carlo simulations were performed to study gas separation in three pairs of isoreticular metal-organic frameworks (IRMOFs) with and without catenation at room temperature.Mixture composed of CO2 and H2 was selected as the model system to separate.The results show that CO2 selectivity in catenated MOFs with multi-porous frameworks is much higher than their non-catenated counterparts.The simulations also show that the electrostatic interactions are very important for the selectivity,and the contributions of different electrostatic interactions are different,depending on pore size,pressure and mixture composition.In fact,changing the electrostatic interactions can even qualitatively change the adsorption behavior.A general conclusion is that the electrostatic interactions between adsorbate molecules and the framework atoms play a dominant role at low pressures,and these interactions in catenated MOFs have much more pronounced effects than those in their non-catenated counterparts,while the electrostatic interactions between adsorbate molecules become evident with increasing pressure,and eventually dominant.展开更多
An efficient and environmentally friendly procedure was described for easy product isolation for the oxidation of cyclohexane with tert-butyl-hydroperoxide catalyzed by titanium silicalite 1 （TS-1） in ambient-temper...An efficient and environmentally friendly procedure was described for easy product isolation for the oxidation of cyclohexane with tert-butyl-hydroperoxide catalyzed by titanium silicalite 1 （TS-1） in ambient-temperature ionic liquid [emim]BF4. Good yield and higher selectivity of products were found in the ionic liquid compared with in molecular solvent. The research results showed 13.2% conversion of cyclohexane, 97.6% cyclohexanol and cyclohexanone selectivity were obtained in ionic liquid under mild conditions of 90℃.展开更多
文摘The microstructures and thermodynamic properties of mixed systems comprising pyridinium ionic liquid[HPy][BF_(4)]and acetonitrile at different mole fractions were studied using molecular dynamics simulation in this work.The following properties were determined:density,self-diffusion coefficient,excess molar volume,and radial distribution function.The results show that with an increase in the mole fraction of[HPy][BF_(4)],the self-diffusion coefficient decreases.Additionally,the excess molar volume initially decreases,reaches a minimum,and then increases.The rules of radial distribution functions(RDFs)of characteristic atoms are different.With increasing the mole fraction of[HPy][BF_(4)],the first peak of the RDFs of HA1-F decreases,while that of CT6-CT6 rises at first and then decreases.This indicates that the solvent molecules affect the polar and non-polar regions of[HPy][BF_(4)]differently.
基金supported by the National Natural Science Foundation of China(No.21501015)the Hunan Provincial Natural Science Foundation,China(No.2022JJ30604)Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation,China(No.2022CL01)。
文摘A composite solid electrolyte comprising a Cu-Al bimetallic metal-organic framework(CAB),lithium salt(LiTFSI)and polyethylene oxide(PEO)was fabricated through molecular grafting to enhance the ionic conductivity of the PEO-based electrolytes.Experimental and molecular dynamics simulation results indicated that the electrolyte with 10 wt.%CAB(PL-CAB-10%)exhibits high ionic conductivity(8.42×10~(-4)S/cm at 60℃),high Li+transference number(0.46),wide electrochemical window(4.91 V),good thermal stability,and outstanding mechanical properties.Furthermore,PL-CAB-10%exhibits excellent cycle stability in both Li-Li symmetric battery and Li/PL-CAB-10%/LiFePO4 asymmetric battery setups.These enhanced performances are primarily attributable to the introduction of the versatile CAB.The abundant metal sites in CAB can react with TFSI~-and PEO through Lewis acid-base interactions,promoting LiTFSI dissociation and improving ionic conductivity.Additionally,regular pores in CAB provide uniformly distributed sites for cation plating during cycling.
文摘Thispaper has investigated the coordination and supramolecular assemblies of alkali metal ions,cucurbit[5]uril(Q[5]),and[CdCl_(4)]^(2-)to confirm whether[CdCl_(4)]^(2-)can produce the“honeycomb effect”,induce coordination of alkali metal ions to Q[5],and form linear coordination polymers.In this work,the effect of alkali metal ions on the construction of Q[5]-Cd^(2+)ion system under acidic conditions was investigated.Five complexes were successfully obtained by solvent evaporation method.Among the five crystal structures obtained,it can be observed that the presence of[CdCl_(4)]^(2-)did not result in the complexation of alkali metal ions by the Q[5]molecule.Instead,a bowl-like Cd^(2+)@Q[5]complex was formed.Indeed,[CdCl_(4)]^(2-)did not produce the honeycomb effect but led to the formation of Q[5]-based honeycomb frameworks with hexagonal cellsoccupied by[CdCl_(4)]^(2-).The experimental results show that cadmium ion showed stronger ability to coordinate to Q[5]in HCl solution.
基金supported by the National Natural Science Foundation of China(2106700421567008+5 种基金21263005)Project of Jiangxi Province Natural Science Foundation China(20133BAB21003)Training Programs of Innovation and Entrepreneurship for Undergraduates of Jiangxi Province(201310407046)The Landing Project of Science and Technology of Colleges and Universities in Jiangxi Province(KJLD14046)Young Scientist Training Project of Jiangxi Province(20122BCB23015)Yuanhang Engineering of Jiangxi Province~~
文摘Rod-shaped PbW O4 microcrystals of length 1 μm were fabricated by a hydrothermal route and subsequent calcination. Pt nanoparticles（NPs） of different contents（0.5 wt%,1 wt% and 2 wt%） were subsequently deposited on the PbW O4 microcrystals,producing robust Pt/PbW O4 composite microcrystals. The PbW O4 microcrystals and Pt/PbW O4 photocatalysts were characterized by X-ray diffraction,N2 sorption measurements,scanning electron microscopy,transmission electron microscopy,and X-ray photoelectron,photoluminescence,Fourier-transform infrared,and ultraviolet-visible diffuse reflectance spectroscopies. The photocatalytic performances of the catalysts were evaluated by the consecutive photocatalytic degradation of acid orange II dye. The Pt/PbW O4 composite microcrystals exhibited high photocatalytic activity and stability. The deposition of Pt NPs produced surface plasmon resonance（SPR）,which induced a large visible light absorption. A Pt NP content of 1-2 wt% resulted in an ~2 times increase in photocatalytic activity,compared with the activity of Pt/PbW O4. The crystal structure and high crystallinity of PbW O4 resulted in its favorable photocatalytic property,and the SPR effect of the Pt NPs promoted visible light harvesting. The Pt NPs also enhanced the separation of photo-generated electrons and holes,which further promoted the photocatalytic reaction.
基金This work was supported by the Natural Science Foundation of Universities of Inner Mongolia Autonomous Region （No.NG09168 and NG10239）.
文摘A new anion receptor bearing phenolic hydroxy group based on 3,5- ditertbutylsalicylaldehyde-p-nitrophenylhydrazone （1） was designed and synthesized. Upon addition of AcO- and F-, the receptor exhibited visible color changes from deep yellow to purple. However, no obvious color changes were observed on addition of the other anions tested （H2PO4-, Cl-, Br-, I-）. The binding properties of the receptor with anions such as AcO and F- were investigated by UV-Vis and fluorescent titrations. The result indicated that the receptor 1 had a higher affinity to AcO- and F- and a 1：1 host-guest complex was formed through H-bond interactions between 1 and anions.
基金Research Project Supported by Shanxi Scholarship Council of China(No.2012-69)Selected Research Project by Department of Human Resources and Social Security of Shanxi
文摘Spectrum analysis of the plasma has over the years been growing both in methods and instrument, which makes it become a widely used non-contact detection method, without disturbing the arc plasma itself. With noticeable developments in the industry application of the method, a need for careful analysis of the plasma with both time and space identification is desirable. Therefore, a spectral measurement system is developed in this paper for diagnosing arc plasma with time and space identification. With a new hollow probe scanning method, the instrument can be used to provide information like energy distribution of plasma, temperature within the arc plasma, which are of great significance with the requirement of space identification. Furthermore, the system can also be used to capture the instant state of the arc plasma with the synchronic triggering system, which uses high speed photo and electrical signal as the time criterion. The industry applications prove that the system works well for online detection of the arc plasma.
基金support of the authorities of Siksha ‘O’Anusandhan University
文摘A novel solvent extraction process for extraction and separation of copper from other base metal ions using a bifunctional ionic liquid (IL) (trioctylmethylammonium/2,4,4-trimethylpentyl phosphinate, [A336/Cy272]) in kerosene was reported. This IL was found to extract copper more efficiently than the individual extractants Aliquat 336 or Cyanex 272. Formation of an octahedral copper-IL complex was characterized by UV-Visible spectra and metal ligand interaction was confirmed by FTIR spectra. The loading capacity of 0.1 mol/L [A336/Cy272] was found to be 1.71 g/L. Stripping studies reported that 0.298 g/L copper ions were efficiently stripped using 0.1 mol/L sulfuric acid from 0.05 mol/L loaded IL. The selectivity of copper against nickel, cadmium and iron was investigated from their equimolar binary mixtures using 0.05 mol/L [A336/Cy272] in kerosene. The highest separation factorβCu/Cd=8.41 was obtained at pH 3.56. Copper can be effectively separated from nickel over the pH range studied. The IL extracts preferentially iron over copper and the highest separation factorβFe/Cuwas 3246 at pH 2.4. The extraction rate of metal ions from a synthetic solution containing copper with other metal impurities was in the order of Fe>Zn>Cu>Cd>Co>Ni.
文摘Nitrogen and phosphorus co-doped graphene quantum dot-modified Bi5O7 I(NPG/Bi5O7 I)nanorods were fabricated via a simple solvothermal method.The morphology,structure,and optical properties of the as-prepared samples were investigated by X-ray diffraction,scanning electron microscopy,high-resolution transmission electron microscopy,X-ray photoelectron spectroscopy(XPS),and diffused reflectance spectroscopy.The photocatalytic performance was estimated by degrading the broad-spectrum antibiotics tetracycline and enrofloxacin under visible light irradiation.The photodegradation activity of Bi5O7 I improved after its surface was modified with NPGs,which was attributed to an increase in the photogenerated charge transport rate and a decrease in the electron-hole pair recombination efficiency.From the electron spin resonance spectra,XPS valence band data,and free radical trapping experiment results,the main active substances involved in the photocatalytic degradation process were determined to be photogenerated holes and superoxide radicals.A possible photocatalytic degradation mechanism for NPG/Bi5O7 I nanorods was proposed.
基金Supported by the National Natural Science Foundation of China （20725622, 20706002, and 20876006）, Beijing Nova Program （2008B15） and the Dutch STW/CW Separation Technology Program （700.56.655-DPC.6243）.
文摘In this work grand canonical Monte Carlo simulations were performed to study gas separation in three pairs of isoreticular metal-organic frameworks (IRMOFs) with and without catenation at room temperature.Mixture composed of CO2 and H2 was selected as the model system to separate.The results show that CO2 selectivity in catenated MOFs with multi-porous frameworks is much higher than their non-catenated counterparts.The simulations also show that the electrostatic interactions are very important for the selectivity,and the contributions of different electrostatic interactions are different,depending on pore size,pressure and mixture composition.In fact,changing the electrostatic interactions can even qualitatively change the adsorption behavior.A general conclusion is that the electrostatic interactions between adsorbate molecules and the framework atoms play a dominant role at low pressures,and these interactions in catenated MOFs have much more pronounced effects than those in their non-catenated counterparts,while the electrostatic interactions between adsorbate molecules become evident with increasing pressure,and eventually dominant.
基金Supported by the National Natural Science Foundation of China （20776037）.
文摘An efficient and environmentally friendly procedure was described for easy product isolation for the oxidation of cyclohexane with tert-butyl-hydroperoxide catalyzed by titanium silicalite 1 （TS-1） in ambient-temperature ionic liquid [emim]BF4. Good yield and higher selectivity of products were found in the ionic liquid compared with in molecular solvent. The research results showed 13.2% conversion of cyclohexane, 97.6% cyclohexanol and cyclohexanone selectivity were obtained in ionic liquid under mild conditions of 90℃.
