The preparation of Cu nanoparticles by the aqueous solution reduction method was investigated. The effects of different reaction parameters on the preparation of Cu nanoparticles were studied. The optimum conditions f...The preparation of Cu nanoparticles by the aqueous solution reduction method was investigated. The effects of different reaction parameters on the preparation of Cu nanoparticles were studied. The optimum conditions for preparing well-dispersed nanoparticles were found as follows: 0.4 mol/L NaBH4 was added into solution containing 0.2 mol/L Cu2+, 1.0% gelatin dispersant in mass fraction, and 1.2 mol/L NH3?H2O at pH 12 and 313 K. In addition, a series of experiments were performed to discover the reaction process. NH3?H2O was found to be able to modulate the reaction process. At pH=10, Cu2+ was transformed to Cu(NH3)42+ as precursor after the addition of NH3?H2O, and then Cu(NH3)42+ was reduced by NaBH4 solution. At pH=12, Cu2+ was transformed to Cu(OH)2 as precursor after the addition of NH3?H2O, and Cu(OH)2 was then reduced by NaBH4 solution.展开更多
Ionic liquids （ILs） have been regarded as the potential novel solvents for improved analytical- and process-scale separation methods.The development of methods for the recovery of ILs from aqueous solutions to escap...Ionic liquids （ILs） have been regarded as the potential novel solvents for improved analytical- and process-scale separation methods.The development of methods for the recovery of ILs from aqueous solutions to escape contamination and recycle samples will ultimately govern the viability of ILs in the future industrial applications. Therefore, in this paper a new method for separation of ILs from their dilute aqueous solutions and simultaneously purification of water was proposed on the basis of the CO2 hydrate formation. For illustration, the dilute aqueous solutions with concentrations of ILs ranging from 2× 10^-3 mol% to 2×10^-1 mol% were concentrated. The results show that the separation efficiency is very impressive and that the new method is applicable to aqueous solutions of both hydrophobic and hydrophilic ILs. Compared to the literature separation method based on the supercritical CO2, the new method is applicable to lower concentrations, and more importantly, its operation condition is mild.展开更多
Carbonate-bearing fluids widely exist in different geological settings,and play important roles in transporting some elements such as the rare earth elements.They may be trapped as large or small fluid inclusions(with...Carbonate-bearing fluids widely exist in different geological settings,and play important roles in transporting some elements such as the rare earth elements.They may be trapped as large or small fluid inclusions(with the size down to<1μm sometimes),and record critical physical-chemical signals for the formations of their host minerals.Spectroscopic methods like Raman spectroscopy and infrared spectroscopy have been proposed as effective methods to quantify the carbonate concentrations of these fluid inclusions.Although they have some great technical advantages over the conventional microthermometry method,there are still some technical difficulties to overcome before they can be routinely used to solve relevant geological problems.The typical limitations include their interlaboratory difference and poor performance on micro fluid inclusions.This study prepared standard ion-distilled water and K_(2)CO_(3)aqueous solutions at different molarities(from 0.5 to 5.5 mol/L),measured densities,collected Raman and infrared spectra,and explored correlations between the K_(2)CO_(3)molarity and the spectroscopic features at ambient P-T conditions.The result confirms that the Raman O-H stretching mode can be used as an internal standard to determine the carbonate concentrations despite some significant differences among the correlations,established in different laboratories,between the relative Raman intensity of the C-O symmetric stretching mode and that of the O-H stretching mode.It further reveals that the interlaboratory difference can be readily removed by performing one high-quality calibration experiment,provided that later quantifying analyses are conducted using the same Raman spectrometer with the same analytical conditions.Our infrared absorption data were collected from thin fluid films(thickness less than~2μm)formed by pressing the prepared solutions in a Microcompression Cell with two diamond-II plates.The data show that both the O-H stretching mode and the O-H bending mode can be used as internal standards to determine the carbonate concentrations.Since the IR signals of the C-O antisymmetric stretching vibration of the CO32ion,and the O-H stretching and bending vibrations from our thin films are very strong,their relative IR absorbance intensity,if well calibrated,can be used to investigate the micron-sized carbonate-bearing aqueous fluid inclusions.This study establishes the first calibration of this kind,which may have some applications.Additionally,our spectroscopic data suggest that as the K_(2)CO_(3)concentration increases the aqueous solution forms more large water molecule clusters via more intense hydrogen-bonding.This process may significantly alter the physical and chemical behavior of the fluids.展开更多
In this work,an air-blast atomizing column was used to study the CO2 capture performance with aqueous MEA(mono-ethanol-amine)and Na OH solutions.The effects of gas flow rate,the liquid to gas ratio(L/G),the CO2 concen...In this work,an air-blast atomizing column was used to study the CO2 capture performance with aqueous MEA(mono-ethanol-amine)and Na OH solutions.The effects of gas flow rate,the liquid to gas ratio(L/G),the CO2 concentration on the CO2 removal efficiency(η)and the volumetric overall mass transfer coefficient(KGav)were investigated.The air-blast atomizing column was also compared with the pressure spray tower on the studies of the CO2 capture performance.For the aqueous MEA and Na OH solutions,the experimental results show that theηdecreases with increasing gas flow rate and CO2 concentration while it increases with increasing L/G.The effects on KGavare more complicated than those forη.When the CO2 concentration is low(3 vol%),KGavincreases with increasing gas flow rate while decreases with increasing L/G.However,when the CO2 concentration is high(9.5 vol%),as the gas flow rate and L/G increases,KGavincreases first and then decreases.The aqueous MEA solution achieves higherηand KGavthan the aqueous Na OH solution.The air-blast atomizing column shows a good performance on CO2 capture.展开更多
Agglomeration-free nanosized ZrO2-HfO2-Y2O3-Sc2O3 composite powders were successfully synthesized by Sol-Gel technique in heated aqueous solution of alcohol, using analytically pure ZrOCl2 · 8H2O, HfOCl2·8H2...Agglomeration-free nanosized ZrO2-HfO2-Y2O3-Sc2O3 composite powders were successfully synthesized by Sol-Gel technique in heated aqueous solution of alcohol, using analytically pure ZrOCl2 · 8H2O, HfOCl2·8H2O, Y（NO3）3·6H2O, and Sc2O3 as raw materials. The effect of synthesis condition on the size and dispersity of the composite powders was investigated by means of XRD, TEM, and TG-DSC techniques. The results showed that well-dispersed predecessor of ZrO2-HfO2-Y2O3-Sc2O3 composite nanopowders could be obtained. The optional condition ： PEG6000 as dispersant was 1%, alcohol/H2O ratio was 5/1, metallic ion concentration in whole solution was 0.5 mol·L^-1 and the pH value of the solution was 12. After calcined at 620 ℃, the powder obtained was in uniform cubic structure, and its average particle size was about 13 nm, which was good for producing nanocrystalline solid electrolyte.展开更多
All-atom molecular dynamic simulations and 2D-NOESY spectra were used to study the conformations and hydrogen bonds of ACE inhibitory tripeptide Ile-Ile-Pro(IIP) in aqueous and DMSO solutions. RMSD, Dis, Rg and SASA w...All-atom molecular dynamic simulations and 2D-NOESY spectra were used to study the conformations and hydrogen bonds of ACE inhibitory tripeptide Ile-Ile-Pro(IIP) in aqueous and DMSO solutions. RMSD, Dis, Rg and SASA were adopted to characterize the properties of tripeptide Ile-Ile-Pro in the MD simulations. Interestingly, the tripeptide molecule IIP exhibited different behaviors in aqueous and DMSO solutions. In aqueous solution, IIP was very flexible. The conformation could shift between extended and folded states very quickly. However,in DMSO solution, more folded conformations were observed. The interesting phenomena were proved by 2D-NOESY spectra.展开更多
A novel aqueous Sn-S complex solution was applied as precursor to fabricate SnO2 electron selective layers (ESLs) for the hybrid perovskite solar cells (PSCs).The tin and sulfur powder were directly dissolved in a (NH...A novel aqueous Sn-S complex solution was applied as precursor to fabricate SnO2 electron selective layers (ESLs) for the hybrid perovskite solar cells (PSCs).The tin and sulfur powder were directly dissolved in a (NH4)2S water solution to form Sn-S precursor.After depositon and annealing,the SnO2 film was formed,presenting as a low cost and enviromental friendly method for preparation of ESL.The films showed excellent transmittance at visible wavelength range.Moreover,the method exhibited high compatibility for doping using Cu,Cd,Li,and Zn elements.Zn doping (0.05 M) in the as-prepared SnO2 ESL significantly improved perovskite solar cells (PSCs) performance.The highest PCE of 13.17% was achived with 15% enhancement compared to that of undoped SnO2 ESL samples.TiCl4 modifications on SnO2 film improved photovoltaic performance to 14.45%,but resulted in the poor long-term stability,around 80% more degredation than that of PSCs based on Zn-doped SnO2 films.展开更多
The exploration of efficient lead-free perovskite photoelectric active materials to develop high-performance photoelectrochemical(PEC)systems in aqueous solution is crucial to expand their PEC applications.Herein,we s...The exploration of efficient lead-free perovskite photoelectric active materials to develop high-performance photoelectrochemical(PEC)systems in aqueous solution is crucial to expand their PEC applications.Herein,we successfully constructed a high-performance PEC platform using ligand-free perovskite Cs2PdBr6 microcrystals(MCs)as the photoactive substance.The Cs2PdBr6 MCs showed narrow bandgap,wide absorption range,high electronic mobility and good stability in aqueous solutions.Particularly,the Cs2PdBr6 MCs exhibited an excellent photoresponse,the photocurrent density could reach as high as 98μA/cm^(2)under 10.18 mW/cm^(2)light irradiation in the absence of other electron acceptors.In addition of the extremely wide range of response wavelength,wide pH range and accelerated interfacial carrier transfer,the Cs2PdBr6 MCs demonstrated the significant potential of photocathode active material for applications in PEC sensors and optoelectronic devices.Therefore,this work indicates that Cs2PdBr6 MCs design is a highly efficient way to solve the intrinsic issues of perovskite material,predicting a promising strategy for high performance PEC application in aqueous ambience.展开更多
Selectively electrochemical conversion of CO2 into organic fuel using renewable electricity is one of the most sought-after processes.In this paper,we report the electrochemical reduction of CO2(CO2RR)on the nanoporou...Selectively electrochemical conversion of CO2 into organic fuel using renewable electricity is one of the most sought-after processes.In this paper,we report the electrochemical reduction of CO2(CO2RR)on the nanoporous Ag electrodes made of compacted Ag nanoparticles(AgNPs),which were prepared by one-step reduction in the water phase with or without the surfactant sodium dodecyl sulfate(SDS).The scanning electron microscope(SEM)characterizations show that the compacted Ag electrodes have the nanoporous morphology formed by stacking AgNPs.Compared with the nanoporous Ag electrode without SDS modification(C-AgNPs),the SDS-modified AgNPs electrode(C-AgNPs-SDS)is highly effective in improving selective CO production in a wide range of potentials(-0.69 V--1.19 V,vs.RHE),with a Faradaic efficiency of 92.2% and a current density of -8.23 mA·cm^-2 for CO production at -0.79 V(vs.RHE).C-AgNPs-SDS is also catalytically stable with only less than 7% deactivation after 8 h of continuous electrolysis.展开更多
To investigate the effects of salt concentration and freeze-thaw (FT) on the first hydration shell of Zn2+ ions in Zn(NO_3)_2 aqueous solutions, extended X-ray absorption fine structure (EXAFS) spectroscopy was used t...To investigate the effects of salt concentration and freeze-thaw (FT) on the first hydration shell of Zn2+ ions in Zn(NO_3)_2 aqueous solutions, extended X-ray absorption fine structure (EXAFS) spectroscopy was used to examine Zn K-edge EXAFS spectra of Zn(NO_3)_2 aqueous solutions with various concentrations before and after FT treatment. The influences of salt concentration and freeze-thaw on the structural parameters of the first hydration shell of Zn2+ ions, including hydration number, Zn-O distance and thermal disorder, were analyzed. The results show that Zn2+ ions have 3.2―6.8 nearest oxygen neighbors with the Zn-O distance being 0.202―0.207 nm. In highly concen-trated solutions, Zn2+ ions are hydrated with four water molecules in a tetrahedral form. The dilution of Zn(NO_3)_2 aqueous solutions increases the number of water molecules in the first hydration shell of Zn2+ ions to six with their octahedral arrangement. Both the hydration number in the first hydration shell of Zn2+ ions and the degree of thermal disorder increase when the FT treatment is operated in Zn(NO_3)_2 aqueous solutions.展开更多
In this study, biologically inspired silk fibroin grafted polyacrylonitrile(SF-g-PAN) filtration membrane was prepared using ZnCl_2 aqueous solution as solvent, avoiding the use of organic solvents. Phase inversion oc...In this study, biologically inspired silk fibroin grafted polyacrylonitrile(SF-g-PAN) filtration membrane was prepared using ZnCl_2 aqueous solution as solvent, avoiding the use of organic solvents. Phase inversion occurred when Zn^(2+)and Cl-ions gradually diffused into water, creating a well-connected ion channel network and the SF-g-PAN filtration membrane was obtained. The membranes were observed by SEM and 3D ultra-depth microscope. The hydrophilic property, pore size distribution and dye rejection of the membrane were investigated. Results showed that the membrane has no finger hole formation because ZnCl_2 aqueous solution has a lower curing rate parameter compared with organic solvents. SF-gPAN membrane possessed good anti-fouling properties and pH sensitivity. The pore size distribution of the SF-g-PAN membrane was 0.25–1.04 nm. The rejection of direct yellow 27(Mw = 662.6) and amaranth(Mw = 604.5) was 96.51% and 30.63%, with the flux of 72.32 L m^(-2) h^(-1) and 73.83 L m^(-2) h^(-1) respectively at0.1 MPa. The SF-g-PAN membrane has a wide range of applications prospect in fine separation, dye desalination, waste water treatment and biomedical fields.展开更多
The surface tension of carbonated monoethanolamine aqueous solutions from 293.15 to 323.15 K was measured by using an automatic surface tension-meter.A model applicable for the surface tension of MEA-CO2-water mixture...The surface tension of carbonated monoethanolamine aqueous solutions from 293.15 to 323.15 K was measured by using an automatic surface tension-meter.A model applicable for the surface tension of MEA-CO2-water mixtures was proposed and the calculated results agreed well with the experiments.The influences of temperature,MEA concentration and CO2 loading were demonstrated on the basis of experiments and calculations.展开更多
A sensitive fluorescent probe, 2,2＇-bisbenzimidazole （L）, for CN has been developed. This structurally simple receptor displays great selectivity for the cyanide anion over other common inorganic anions in an aqueo...A sensitive fluorescent probe, 2,2＇-bisbenzimidazole （L）, for CN has been developed. This structurally simple receptor displays great selectivity for the cyanide anion over other common inorganic anions in an aqueous environment. In addition, further study demonstrates the lower detection of the fluorescence response of the sensor to CN is in 10 9 mol/L range. Thus, the present probe should be applicable as a practical system for the monitoring of cyanide concentrations in aqueous samples.展开更多
文摘The preparation of Cu nanoparticles by the aqueous solution reduction method was investigated. The effects of different reaction parameters on the preparation of Cu nanoparticles were studied. The optimum conditions for preparing well-dispersed nanoparticles were found as follows: 0.4 mol/L NaBH4 was added into solution containing 0.2 mol/L Cu2+, 1.0% gelatin dispersant in mass fraction, and 1.2 mol/L NH3?H2O at pH 12 and 313 K. In addition, a series of experiments were performed to discover the reaction process. NH3?H2O was found to be able to modulate the reaction process. At pH=10, Cu2+ was transformed to Cu(NH3)42+ as precursor after the addition of NH3?H2O, and then Cu(NH3)42+ was reduced by NaBH4 solution. At pH=12, Cu2+ was transformed to Cu(OH)2 as precursor after the addition of NH3?H2O, and Cu(OH)2 was then reduced by NaBH4 solution.
基金supported by the National Natural Science Foundation of China (40673043 and 20576073)the Program for New Century Excellent Talents in University of Ministry of Education of China (NCET-06-0088)
文摘Ionic liquids （ILs） have been regarded as the potential novel solvents for improved analytical- and process-scale separation methods.The development of methods for the recovery of ILs from aqueous solutions to escape contamination and recycle samples will ultimately govern the viability of ILs in the future industrial applications. Therefore, in this paper a new method for separation of ILs from their dilute aqueous solutions and simultaneously purification of water was proposed on the basis of the CO2 hydrate formation. For illustration, the dilute aqueous solutions with concentrations of ILs ranging from 2× 10^-3 mol% to 2×10^-1 mol% were concentrated. The results show that the separation efficiency is very impressive and that the new method is applicable to aqueous solutions of both hydrophobic and hydrophilic ILs. Compared to the literature separation method based on the supercritical CO2, the new method is applicable to lower concentrations, and more importantly, its operation condition is mild.
基金the DREAM project of MOST,China(Grant No.2016YFC0600408)the Strategic Priority Research Program(B)of Chinese Academy of Sciences(Grant No.XDB18000000)the Program of the National Mineral Rock and Fossil Specimens Resource Center from MOST,China.
文摘Carbonate-bearing fluids widely exist in different geological settings,and play important roles in transporting some elements such as the rare earth elements.They may be trapped as large or small fluid inclusions(with the size down to<1μm sometimes),and record critical physical-chemical signals for the formations of their host minerals.Spectroscopic methods like Raman spectroscopy and infrared spectroscopy have been proposed as effective methods to quantify the carbonate concentrations of these fluid inclusions.Although they have some great technical advantages over the conventional microthermometry method,there are still some technical difficulties to overcome before they can be routinely used to solve relevant geological problems.The typical limitations include their interlaboratory difference and poor performance on micro fluid inclusions.This study prepared standard ion-distilled water and K_(2)CO_(3)aqueous solutions at different molarities(from 0.5 to 5.5 mol/L),measured densities,collected Raman and infrared spectra,and explored correlations between the K_(2)CO_(3)molarity and the spectroscopic features at ambient P-T conditions.The result confirms that the Raman O-H stretching mode can be used as an internal standard to determine the carbonate concentrations despite some significant differences among the correlations,established in different laboratories,between the relative Raman intensity of the C-O symmetric stretching mode and that of the O-H stretching mode.It further reveals that the interlaboratory difference can be readily removed by performing one high-quality calibration experiment,provided that later quantifying analyses are conducted using the same Raman spectrometer with the same analytical conditions.Our infrared absorption data were collected from thin fluid films(thickness less than~2μm)formed by pressing the prepared solutions in a Microcompression Cell with two diamond-II plates.The data show that both the O-H stretching mode and the O-H bending mode can be used as internal standards to determine the carbonate concentrations.Since the IR signals of the C-O antisymmetric stretching vibration of the CO32ion,and the O-H stretching and bending vibrations from our thin films are very strong,their relative IR absorbance intensity,if well calibrated,can be used to investigate the micron-sized carbonate-bearing aqueous fluid inclusions.This study establishes the first calibration of this kind,which may have some applications.Additionally,our spectroscopic data suggest that as the K_(2)CO_(3)concentration increases the aqueous solution forms more large water molecule clusters via more intense hydrogen-bonding.This process may significantly alter the physical and chemical behavior of the fluids.
基金Supported by the National Natural Science Foundation of China(21729601,21776123)the Doctoral Program of Higher Education(20133221110001)+1 种基金the Project of Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the Kempe Foundations,and Swedish Energy Agency(P40548-1).
文摘In this work,an air-blast atomizing column was used to study the CO2 capture performance with aqueous MEA(mono-ethanol-amine)and Na OH solutions.The effects of gas flow rate,the liquid to gas ratio(L/G),the CO2 concentration on the CO2 removal efficiency(η)and the volumetric overall mass transfer coefficient(KGav)were investigated.The air-blast atomizing column was also compared with the pressure spray tower on the studies of the CO2 capture performance.For the aqueous MEA and Na OH solutions,the experimental results show that theηdecreases with increasing gas flow rate and CO2 concentration while it increases with increasing L/G.The effects on KGavare more complicated than those forη.When the CO2 concentration is low(3 vol%),KGavincreases with increasing gas flow rate while decreases with increasing L/G.However,when the CO2 concentration is high(9.5 vol%),as the gas flow rate and L/G increases,KGavincreases first and then decreases.The aqueous MEA solution achieves higherηand KGavthan the aqueous Na OH solution.The air-blast atomizing column shows a good performance on CO2 capture.
基金Project supported by the National Natural Science Foundation of China (20101006)Nano Technology Special Foundationof Shanghai Science and Technology Committee (0452nm073) and Shanghai Education Committee
文摘Agglomeration-free nanosized ZrO2-HfO2-Y2O3-Sc2O3 composite powders were successfully synthesized by Sol-Gel technique in heated aqueous solution of alcohol, using analytically pure ZrOCl2 · 8H2O, HfOCl2·8H2O, Y（NO3）3·6H2O, and Sc2O3 as raw materials. The effect of synthesis condition on the size and dispersity of the composite powders was investigated by means of XRD, TEM, and TG-DSC techniques. The results showed that well-dispersed predecessor of ZrO2-HfO2-Y2O3-Sc2O3 composite nanopowders could be obtained. The optional condition ： PEG6000 as dispersant was 1%, alcohol/H2O ratio was 5/1, metallic ion concentration in whole solution was 0.5 mol·L^-1 and the pH value of the solution was 12. After calcined at 620 ℃, the powder obtained was in uniform cubic structure, and its average particle size was about 13 nm, which was good for producing nanocrystalline solid electrolyte.
基金Supported by the National Natural Science Foundation of China(No.20903026)the Talents Introduction Foundation for Universities of Guangdong Province(2011)Scientific Research Foundation of the Natural Science Foundation of Guangdong Province(No.S2011010002483)
文摘All-atom molecular dynamic simulations and 2D-NOESY spectra were used to study the conformations and hydrogen bonds of ACE inhibitory tripeptide Ile-Ile-Pro(IIP) in aqueous and DMSO solutions. RMSD, Dis, Rg and SASA were adopted to characterize the properties of tripeptide Ile-Ile-Pro in the MD simulations. Interestingly, the tripeptide molecule IIP exhibited different behaviors in aqueous and DMSO solutions. In aqueous solution, IIP was very flexible. The conformation could shift between extended and folded states very quickly. However,in DMSO solution, more folded conformations were observed. The interesting phenomena were proved by 2D-NOESY spectra.
基金the National Key Research and Development Plan(2017YFE0131900)the Hubei Provincial Natural Science Foundation of China(2016CFB464)+2 种基金the Fundamental Research Funds for the Central Universities(WUT:2016IVA089,2016III030)the Hubei Key Laboratory of Low Dimensional Optoelectronic Material and Devices(HLOM151002)“Chutian Scholar Program”of Hubei Province,China。
文摘A novel aqueous Sn-S complex solution was applied as precursor to fabricate SnO2 electron selective layers (ESLs) for the hybrid perovskite solar cells (PSCs).The tin and sulfur powder were directly dissolved in a (NH4)2S water solution to form Sn-S precursor.After depositon and annealing,the SnO2 film was formed,presenting as a low cost and enviromental friendly method for preparation of ESL.The films showed excellent transmittance at visible wavelength range.Moreover,the method exhibited high compatibility for doping using Cu,Cd,Li,and Zn elements.Zn doping (0.05 M) in the as-prepared SnO2 ESL significantly improved perovskite solar cells (PSCs) performance.The highest PCE of 13.17% was achived with 15% enhancement compared to that of undoped SnO2 ESL samples.TiCl4 modifications on SnO2 film improved photovoltaic performance to 14.45%,but resulted in the poor long-term stability,around 80% more degredation than that of PSCs based on Zn-doped SnO2 films.
基金funded by the National Natural Science Foundation of China(22374021)the Joint Funds for the Innovation of Science and Technology of Fujian Province(2021Y9010)+2 种基金Zong Lian Plan Talent Support Project of the Fujian Medical University(XN240006)Program for Fujian Youth Talent Support Project(2019B016)Program for Fujian Top-notch Innovative Personnel(Fujian Commission Talent[2018]No.5).
文摘The exploration of efficient lead-free perovskite photoelectric active materials to develop high-performance photoelectrochemical(PEC)systems in aqueous solution is crucial to expand their PEC applications.Herein,we successfully constructed a high-performance PEC platform using ligand-free perovskite Cs2PdBr6 microcrystals(MCs)as the photoactive substance.The Cs2PdBr6 MCs showed narrow bandgap,wide absorption range,high electronic mobility and good stability in aqueous solutions.Particularly,the Cs2PdBr6 MCs exhibited an excellent photoresponse,the photocurrent density could reach as high as 98μA/cm^(2)under 10.18 mW/cm^(2)light irradiation in the absence of other electron acceptors.In addition of the extremely wide range of response wavelength,wide pH range and accelerated interfacial carrier transfer,the Cs2PdBr6 MCs demonstrated the significant potential of photocathode active material for applications in PEC sensors and optoelectronic devices.Therefore,this work indicates that Cs2PdBr6 MCs design is a highly efficient way to solve the intrinsic issues of perovskite material,predicting a promising strategy for high performance PEC application in aqueous ambience.
文摘Selectively electrochemical conversion of CO2 into organic fuel using renewable electricity is one of the most sought-after processes.In this paper,we report the electrochemical reduction of CO2(CO2RR)on the nanoporous Ag electrodes made of compacted Ag nanoparticles(AgNPs),which were prepared by one-step reduction in the water phase with or without the surfactant sodium dodecyl sulfate(SDS).The scanning electron microscope(SEM)characterizations show that the compacted Ag electrodes have the nanoporous morphology formed by stacking AgNPs.Compared with the nanoporous Ag electrode without SDS modification(C-AgNPs),the SDS-modified AgNPs electrode(C-AgNPs-SDS)is highly effective in improving selective CO production in a wide range of potentials(-0.69 V--1.19 V,vs.RHE),with a Faradaic efficiency of 92.2% and a current density of -8.23 mA·cm^-2 for CO production at -0.79 V(vs.RHE).C-AgNPs-SDS is also catalytically stable with only less than 7% deactivation after 8 h of continuous electrolysis.
基金Supported by National Natural Science Foundation of China(No. 20776096)National Synchrotron Radiation Laboratory, China(No. 20081005G)
文摘To investigate the effects of salt concentration and freeze-thaw (FT) on the first hydration shell of Zn2+ ions in Zn(NO_3)_2 aqueous solutions, extended X-ray absorption fine structure (EXAFS) spectroscopy was used to examine Zn K-edge EXAFS spectra of Zn(NO_3)_2 aqueous solutions with various concentrations before and after FT treatment. The influences of salt concentration and freeze-thaw on the structural parameters of the first hydration shell of Zn2+ ions, including hydration number, Zn-O distance and thermal disorder, were analyzed. The results show that Zn2+ ions have 3.2―6.8 nearest oxygen neighbors with the Zn-O distance being 0.202―0.207 nm. In highly concen-trated solutions, Zn2+ ions are hydrated with four water molecules in a tetrahedral form. The dilution of Zn(NO_3)_2 aqueous solutions increases the number of water molecules in the first hydration shell of Zn2+ ions to six with their octahedral arrangement. Both the hydration number in the first hydration shell of Zn2+ ions and the degree of thermal disorder increase when the FT treatment is operated in Zn(NO_3)_2 aqueous solutions.
基金supported by the National Natural Science Foundation of China (Nos. 51678409, 145 708407, 21476172)Tianjin Science Technology Research Funds of China (Nos. 16JCZDJC37500, 15JCZDJC38300)+1 种基金Program for Innovative Research Team in University of Tianjin (No. TD13-5042)Science Foundation for the Youth Teachers of Peking Union Medical College (No. 2014ZLGC0754)
文摘In this study, biologically inspired silk fibroin grafted polyacrylonitrile(SF-g-PAN) filtration membrane was prepared using ZnCl_2 aqueous solution as solvent, avoiding the use of organic solvents. Phase inversion occurred when Zn^(2+)and Cl-ions gradually diffused into water, creating a well-connected ion channel network and the SF-g-PAN filtration membrane was obtained. The membranes were observed by SEM and 3D ultra-depth microscope. The hydrophilic property, pore size distribution and dye rejection of the membrane were investigated. Results showed that the membrane has no finger hole formation because ZnCl_2 aqueous solution has a lower curing rate parameter compared with organic solvents. SF-gPAN membrane possessed good anti-fouling properties and pH sensitivity. The pore size distribution of the SF-g-PAN membrane was 0.25–1.04 nm. The rejection of direct yellow 27(Mw = 662.6) and amaranth(Mw = 604.5) was 96.51% and 30.63%, with the flux of 72.32 L m^(-2) h^(-1) and 73.83 L m^(-2) h^(-1) respectively at0.1 MPa. The SF-g-PAN membrane has a wide range of applications prospect in fine separation, dye desalination, waste water treatment and biomedical fields.
基金support from the National Natural Science Foundation of China (21076070)the Natural Science Funds for Distinguished Young Scholar of Hebei Province (B2012502076)+1 种基金Fundamental Research Funds for the Central Universities (11ZG10)the 111 project (B12034)
文摘The surface tension of carbonated monoethanolamine aqueous solutions from 293.15 to 323.15 K was measured by using an automatic surface tension-meter.A model applicable for the surface tension of MEA-CO2-water mixtures was proposed and the calculated results agreed well with the experiments.The influences of temperature,MEA concentration and CO2 loading were demonstrated on the basis of experiments and calculations.
基金supported by the National Natural Science Foundation of China(Nos.21064006,21262032 and 21161018)the Program for Changjiang Scholars and Innovative Research Team in University of Ministry of Education of China(No.IRT1177)+2 种基金the Natural Science Foundation of Gansu Province(No.1010RJZA018)the Youth Foundation of Gansu Province(No.2011GS04735)NWNU-LKQN-11-32
文摘A sensitive fluorescent probe, 2,2＇-bisbenzimidazole （L）, for CN has been developed. This structurally simple receptor displays great selectivity for the cyanide anion over other common inorganic anions in an aqueous environment. In addition, further study demonstrates the lower detection of the fluorescence response of the sensor to CN is in 10 9 mol/L range. Thus, the present probe should be applicable as a practical system for the monitoring of cyanide concentrations in aqueous samples.
