Cu/SiO2 catalysts prepared by a convenient and efficient method using the urea hydrolysis deposition-precipitation （UHDP） technique have been proposed focusing on the effect of copper loading.The texture,structure a...Cu/SiO2 catalysts prepared by a convenient and efficient method using the urea hydrolysis deposition-precipitation （UHDP） technique have been proposed focusing on the effect of copper loading.The texture,structure and composition are systematically characterized by ICP,FTIR,N 2-physisorption,N2O chemisorption,TPR,XRD and XPS.The formation of copper phyllosilicate is observed in Cu/SiO2 catalyst by adopting UHDP method,and the amount of copper phyllosilicate is related to copper loading.It is found the structure properties and catalytic performance is profoundly affected by the amount of copper phyllosilicate.The excellent catalytic activity is attributed to the synergetic effect between Cu0 and Cu ＋.DMO conversion and EG selectivity are determined by the amount of Cu0 and Cu＋,respectively.The proper copper loading （30 wt%） provides with the highest ratio of Cu ＋ /Cu0,giving rise to the highest EG yield of 95% under the reaction conditions of p=2.0 MPa,T=473 K,H2/DMO=80 and LHSV=1.0h-1.展开更多
Cu（OH）2 nano-fibers were prepared by chemical precipitation with CuSO4·5H2O and NaOH as raw materials. The Cu（OH）2 nano-fibers have a diameter of 10-30 nm and a length of 1-6 μm. The reaction conditions were...Cu（OH）2 nano-fibers were prepared by chemical precipitation with CuSO4·5H2O and NaOH as raw materials. The Cu（OH）2 nano-fibers have a diameter of 10-30 nm and a length of 1-6 μm. The reaction conditions were as follows： the concentration of CuSO4 solution was 0.1 mol·L^-1,NaOH solution 4 mol·L^-1,the dropping rate of the NaOH solution 50 mL·min^-1,the reaction temperature 20℃the pH value of the reaction terminal 13,and the stirring rate 1200 r·min^-1. The chain nano-CuO grains were obtained through the microwave radiation of the Cu（OH）2 nano-fibers.展开更多
To determine the environmental free metal ion activity was a recent hot issue. A method to measure low-level free cupric ion activity in soil solution extracted with 0.01 mol/L KNO3 was developed by using cupric ion-s...To determine the environmental free metal ion activity was a recent hot issue. A method to measure low-level free cupric ion activity in soil solution extracted with 0.01 mol/L KNO3 was developed by using cupric ion-selective electrode （ISE） and calibrating with Cu-buffer solution. Three copper buffers including iminodiacetic acid （IDA）, ethylenediamine （EN）, and glycine （Gly） were compared for calibrating the Cu-ISE curves in the range of free cupric ions （pCu^2＋） 7-13. The Cu-EN buffer showed the best electrode response and thus was applied as the calibration buffer. The pCu^2＋ of 39 contaminated agricultural soils around a copper mine was measured, ranging from 5.03 to 9.20. Most Cu in the soil solutions was found to be complexed with dissolved soil organic matters, averaging 98.1%. The proportion of free Cu^2＋ ions in the soil solutions decreased with the increasing of solution pH. Soluble Cu and free Cu^2＋ ions concentrations were analyzed by multiple linear regressions to evaluate the effects of soil properties on metal levels and speciation. The results showed that soil solution pH was the most significant factor influencing pCu^2＋ （with R^2 value of 0.76）, while not important for the soluble Cu concentration.展开更多
Objective To compare the cupric ion releasing in vitro o.f the three IUDs. Methods The stability o.f cupric ion releasing o.f IUDs including TCu 380.4 IUD （TCu 380A）, Multiload Cu375 IUD （MCu 375） and Yuangong 365...Objective To compare the cupric ion releasing in vitro o.f the three IUDs. Methods The stability o.f cupric ion releasing o.f IUDs including TCu 380.4 IUD （TCu 380A）, Multiload Cu375 IUD （MCu 375） and Yuangong 365 copper-bearing indomethacin-releasing IUD （Yuangong 365） by the determination of cupric ion releasing in simulated uterine fluid. The simulated uterine fluid was used for releasing media. Copper ion was determined by flame atomic absorption spectrometer. Results The cupric ion releasing of three IUDs were instable at the beginning and tend to be stable gradually. In the stable phase, the average level of cupric ion releasing of TCu380A, MCu375 and Yuangong 365 were 4.25±2.71-7.62±6.42 μg, 4.92±1.23 -8.62±3.08 μg and 2.19±0.40-4.68±1.66 μg, respectively. TCu380A had higher instable releasing level than those of Yuangong 365 （P〈0. 05）. Conclusion TCu 380.4 and MCu 375 showed a ＂burst release＂ during the first few days and the.former was of great significance（P〈0.05）. The initial cupric ion releasing of Yuangong 365 appeared to be the lowest, followed by MCu375 and TCu380A in a releasing order展开更多
Antibacterial activity of AISI420 stainless steel (SS) implanted by copper was investigated. Ions extracted from a metal vapor vacuum arc (MEVVA) are sourced with 100keV energy and a dose range from 0.2×1017 to 2...Antibacterial activity of AISI420 stainless steel (SS) implanted by copper was investigated. Ions extracted from a metal vapor vacuum arc (MEVVA) are sourced with 100keV energy and a dose range from 0.2×1017 to 2.0×1017ions·cm-2. The saturation dose of Cu implantation in AISI420 SS and Cu surface concentration were calculated at the energy of 100keV. The effect of dose on the antibacterial activity was analyzed. Results of antibacterial test show that the saturation dose is the optimum implantation dose for best antibacterial activity, which is above 99% against both Escherichia coli and Staphylococcus aureus. Novel phases such as Fe4Cu3 and Cu9.9Fe0.1 were found in the implanted layer by glancing angle X-ray diffraction (GXRD). The antibacterial activity of AISI420 SS attributes to Cu-contained phase.展开更多
Two binuclear copper(I) complexes with novel structures and novel bonding,Cu_2(Ph_2PCH_2PPh_2)Cl_2 (Ph_2PCH_2PPh_2=dppm) and Cu_2(Ph_2P-CH_2CH_2PPh_2)Cl_2 (Ph_2PCH_2CH_2PPh_2=dppe), were prepared and characterized thr...Two binuclear copper(I) complexes with novel structures and novel bonding,Cu_2(Ph_2PCH_2PPh_2)Cl_2 (Ph_2PCH_2PPh_2=dppm) and Cu_2(Ph_2P-CH_2CH_2PPh_2)Cl_2 (Ph_2PCH_2CH_2PPh_2=dppe), were prepared and characterized through elemental analyses, ICP, IR(4000-200 cm^(-1), CsI disc.), ^(31)P-NMR spectra. Their electronic conductivities, oxidation and reduction potentials were measured. Preliminary studies show that both of the two complexes have chlorobridging and phosphorus-bridging structures.展开更多
Binuclear Cu(Ⅰ) complex [Cu(dppm)(NO_3)]2 (dppm=Ph_2PCH_2PPh_2) and mononuclear Cu(Ⅰ) complex [Cu(dppe)(NO_3)] (dppe=Ph_2PCH_2CH_2PPh_2) have been synthesized by the ligand-reduction reaction of cupric nitrate with ...Binuclear Cu(Ⅰ) complex [Cu(dppm)(NO_3)]2 (dppm=Ph_2PCH_2PPh_2) and mononuclear Cu(Ⅰ) complex [Cu(dppe)(NO_3)] (dppe=Ph_2PCH_2CH_2PPh_2) have been synthesized by the ligand-reduction reaction of cupric nitrate with dppm and dppe in methanol and characterized by means of ICP, elemental analyses, molecular weight determination, TG, ^(31)P-NMR, IR and Raman spectra; their electronic conductivities and CV waves have also been measured. Results show that dppm coordinates to the Cu(Ⅰ) atoms as a bridging bidentate ligand and dppe as a chelating bidentate ligand, (NO_3)^(-1) behaves as a chelating bidentate ligand in both of the newly prepared complexes.展开更多
In conditions of monochromatic excitation (λexc=337.1), the spectral dependence of the efficiency of fluorescence quenching αλ of humic acids samples by Cd2+ and Cu2+ ions was studied. The difference of αλ depend...In conditions of monochromatic excitation (λexc=337.1), the spectral dependence of the efficiency of fluorescence quenching αλ of humic acids samples by Cd2+ and Cu2+ ions was studied. The difference of αλ dependencies for these ions was established. In the spectral range 350 - 650 nm, changes of the αλ for Cd2+ ion are markedly different from the magnitude for changes αλ, which occur for ion Cu2+. The interpretation of mismatch dependences obtained αλ ions Cd2+ and Cu2+ is carried out within the concept of the availability of different sites, due to the difference in ionic radii (0.108 nm and 0.08 nm for Cd2+ and Cu2+, respectively).展开更多
A new near-infrared fluorophore 2-(2-Aminoethyl) pyridine-tricarbocyanine (1) was rationally designed and synthe-sized as a fluorescent probe for detection of Cu2+ with high selectivity. The response of Probe 1 is bas...A new near-infrared fluorophore 2-(2-Aminoethyl) pyridine-tricarbocyanine (1) was rationally designed and synthe-sized as a fluorescent probe for detection of Cu2+ with high selectivity. The response of Probe 1 is based on the fluorescence quenching upon binding to Cu2+. The sensing performance of the proposed Cu2+-sensitive Probe 1 was then investigated. The probe can be applied to the quantification detection of Cu2+ with a linear concentration range covering from 4.8 × 10-7 to 1.6 × 10-4 mol/L and a detection limit of 9.3 × 10-8 mol/L. The experimental results showed that the response of 1 to Cu2+ was independent of pH in medium condition (pH 6.0-8.0), and exhibited excellent selectivity towards Cu2+ over other common metal cations.展开更多
Cu2ZnSnS4 (CZTS) thin films were successfully prepared by sulfurization of ion bean sputtered precursors on soda-lime glass substrate. The single phase of stannite-type structure CZTS films were obtained as revealed i...Cu2ZnSnS4 (CZTS) thin films were successfully prepared by sulfurization of ion bean sputtered precursors on soda-lime glass substrate. The single phase of stannite-type structure CZTS films were obtained as revealed in EDS and XRD analysis when the ratios of the constituents of CZTS thin films are close to stoichiometric by optimizing the conditions of precursor preparation and sulfurization. A low sheet resistivity as about 0.156 Ω·cm and a high absorption coefficient as 1×104 cm-1 were achieved in this method by Hall effect measurements and UV-VIS spectrophotometer. The optical band-gap energy of the CZTS sample is about 1.51 eV, which is very close to the optimum value for a solar-cell absorber.展开更多
Highly oxidation. SEM analysis ordered anatase titania nanotube method was used to characterize arrays （TINT） were fabricated by anodic the morphology of the prepared samples. TiNT samples doped with Cu ions were pr...Highly oxidation. SEM analysis ordered anatase titania nanotube method was used to characterize arrays （TINT） were fabricated by anodic the morphology of the prepared samples. TiNT samples doped with Cu ions were prepared by home-made Metal Vapor Vacuum Arc ions sources （MEVVA, BNU, China） implanter. Photo-electric response and methyl orange decomposition ability of implanted samples under UV and visible light were tested, and the results indicated that the performance of Cu/TiNT enhanced significantly under visible light; it was noteworthy that the photocurrent density of A-Cu/TiNT was 0.102 mA/cm^2, which was 115 times that of pure TINT, and degradation ability of TiNT also strongly enhanced under visible light. In a word, the absorption spectrum of implanted anatase titania shifted to a longer wavelength region. Theoretic study on Cu-doped anatase based on density functional theory was carried out in this paper to validate the experiment results. The calculation results are depicted as follows： Intermittent energy band appeared around the Fermi energy after doping with Cu metal, the width of which was 0.35 eV and the location of valence and conduction bands shifted to the lower energy level by 0.22 eV; more excitation and jump routes were opened for the electrons. The narrowed band gaps allowed the photons with lower energy （at longer wavelength, such as visible light） to be absorbed, which accorded well with the experimental results.展开更多
In this paper, we report photoelectrochemical（PEC） conversion of carbon dioxide（CO_2） using photocathodes based on Cu_2O nanowires（NWs） overcoated with Cu~＋-incorporated crystalline TiO_2（TiO_2–Cu~＋ ）shell....In this paper, we report photoelectrochemical（PEC） conversion of carbon dioxide（CO_2） using photocathodes based on Cu_2O nanowires（NWs） overcoated with Cu~＋-incorporated crystalline TiO_2（TiO_2–Cu~＋ ）shell. Cu_2O NW photocathodes show remanent photocurrent of 5.3% after 30 min of PEC reduction of CO_2.After coating Cu_2O with TiO_2–Cu~＋ overlayer, the remanent photocurrent is 27.6%, which is an increase by5.2 fold. The charge transfer resistance of Cu_2O/TiO_2–Cu~＋ is 0.423 k/cm2, whereas Cu_2O photocathode shows resistivity of 0.781 k/cm2 under irradiation. Mott–Schottky analysis reveals that Cu~＋ species embedded in TiO_2 layer is responsible for enhanced adsorption of CO_2 on TiO_2 surface, as evidenced by the decrease of capacitance in the Helmholtz layer. On account of these electrochemical and electronic effects by the Cu~＋ species, the Faradaic efficiency（FE） of photocathodes reaches as high as 56.5% when TiO_2–Cu~＋ is added to Cu_2O, showing drastic increase from 23.6% by bare Cu_2O photocathodes.展开更多
A novel thermally induced graft polymerization technique was used to modify a polyvinylidene fluoride （PVDF） hollow fibre microfiltration membrane. An artificial neural network （ANN） was applied to optimize the pr...A novel thermally induced graft polymerization technique was used to modify a polyvinylidene fluoride （PVDF） hollow fibre microfiltration membrane. An artificial neural network （ANN） was applied to optimize the prepared condition of the membrane. The optimized dosing of acrylic acid （AA）, acrylamide （AM）, N, N＇- methylenebisacrylamide （NMBA） and potassium persulphate （KSP） designed by ANN was that AA was 40.63 ml/L; AM acted as 6.25 g/L; NMBA was 1.72 g/L and KSP was 1.5 g/L, respectively. The thermal stability of the PVDF modified hollow fibre membrane （PVDF-PAA） was investigated by thermogravimetric （TG） and differential scanning calorimetry （DSC） analysis. The polycrystallinity of the PVDF-PAA membrane was evaluated by X-ray diffraction （XRD） analysis. The complex formation of the modified membrane was ascertained by Fourier transform infrared spectroscopy （FTIR）. The morphology of the PVDF-PAA membrane was studied by environmental scanning electron microscopy （ESEM）. The surface compositions of the membrane were analyzed by X-ray photoelectron spectroscopy （XPS）. The adsorption capacity of Cu^2＋ ion on the PVDF-PAA hollow fibre membrane was also investigated.展开更多
1 INTRODUCTIONKnowledge of the basic transport phenomena of ions in an ion exchange membrane isimportant for the application of such a membrane.Various studies on the developmentof mathematical models for predicting a...1 INTRODUCTIONKnowledge of the basic transport phenomena of ions in an ion exchange membrane isimportant for the application of such a membrane.Various studies on the developmentof mathematical models for predicting and correlating membrane transport rate havebeen published in recent years.More exact estimation of the diffusion coefficientshas been the subject of chief concern in many of these papers.For a bi-ionic systemwith the same valence,Sato et al.gave a method for estimating diffusion coefficients展开更多
文摘Cu/SiO2 catalysts prepared by a convenient and efficient method using the urea hydrolysis deposition-precipitation （UHDP） technique have been proposed focusing on the effect of copper loading.The texture,structure and composition are systematically characterized by ICP,FTIR,N 2-physisorption,N2O chemisorption,TPR,XRD and XPS.The formation of copper phyllosilicate is observed in Cu/SiO2 catalyst by adopting UHDP method,and the amount of copper phyllosilicate is related to copper loading.It is found the structure properties and catalytic performance is profoundly affected by the amount of copper phyllosilicate.The excellent catalytic activity is attributed to the synergetic effect between Cu0 and Cu ＋.DMO conversion and EG selectivity are determined by the amount of Cu0 and Cu＋,respectively.The proper copper loading （30 wt%） provides with the highest ratio of Cu ＋ /Cu0,giving rise to the highest EG yield of 95% under the reaction conditions of p=2.0 MPa,T=473 K,H2/DMO=80 and LHSV=1.0h-1.
文摘Cu（OH）2 nano-fibers were prepared by chemical precipitation with CuSO4·5H2O and NaOH as raw materials. The Cu（OH）2 nano-fibers have a diameter of 10-30 nm and a length of 1-6 μm. The reaction conditions were as follows： the concentration of CuSO4 solution was 0.1 mol·L^-1,NaOH solution 4 mol·L^-1,the dropping rate of the NaOH solution 50 mL·min^-1,the reaction temperature 20℃the pH value of the reaction terminal 13,and the stirring rate 1200 r·min^-1. The chain nano-CuO grains were obtained through the microwave radiation of the Cu（OH）2 nano-fibers.
基金The National Key Basic Research Program (973) of China (No. 2002CB410808) and CAS Research Program on Soil Biosystems andAgro-Product Safety (No. CXTD-Z2005-4-1)
文摘To determine the environmental free metal ion activity was a recent hot issue. A method to measure low-level free cupric ion activity in soil solution extracted with 0.01 mol/L KNO3 was developed by using cupric ion-selective electrode （ISE） and calibrating with Cu-buffer solution. Three copper buffers including iminodiacetic acid （IDA）, ethylenediamine （EN）, and glycine （Gly） were compared for calibrating the Cu-ISE curves in the range of free cupric ions （pCu^2＋） 7-13. The Cu-EN buffer showed the best electrode response and thus was applied as the calibration buffer. The pCu^2＋ of 39 contaminated agricultural soils around a copper mine was measured, ranging from 5.03 to 9.20. Most Cu in the soil solutions was found to be complexed with dissolved soil organic matters, averaging 98.1%. The proportion of free Cu^2＋ ions in the soil solutions decreased with the increasing of solution pH. Soluble Cu and free Cu^2＋ ions concentrations were analyzed by multiple linear regressions to evaluate the effects of soil properties on metal levels and speciation. The results showed that soil solution pH was the most significant factor influencing pCu^2＋ （with R^2 value of 0.76）, while not important for the soluble Cu concentration.
基金This study was supported by National Key Scientific and Technological Project(2004BA720A32)
文摘Objective To compare the cupric ion releasing in vitro o.f the three IUDs. Methods The stability o.f cupric ion releasing o.f IUDs including TCu 380.4 IUD （TCu 380A）, Multiload Cu375 IUD （MCu 375） and Yuangong 365 copper-bearing indomethacin-releasing IUD （Yuangong 365） by the determination of cupric ion releasing in simulated uterine fluid. The simulated uterine fluid was used for releasing media. Copper ion was determined by flame atomic absorption spectrometer. Results The cupric ion releasing of three IUDs were instable at the beginning and tend to be stable gradually. In the stable phase, the average level of cupric ion releasing of TCu380A, MCu375 and Yuangong 365 were 4.25±2.71-7.62±6.42 μg, 4.92±1.23 -8.62±3.08 μg and 2.19±0.40-4.68±1.66 μg, respectively. TCu380A had higher instable releasing level than those of Yuangong 365 （P〈0. 05）. Conclusion TCu 380.4 and MCu 375 showed a ＂burst release＂ during the first few days and the.former was of great significance（P〈0.05）. The initial cupric ion releasing of Yuangong 365 appeared to be the lowest, followed by MCu375 and TCu380A in a releasing order
基金This work was supported by the National Natural Science Foundation of China(No.50101009)
文摘Antibacterial activity of AISI420 stainless steel (SS) implanted by copper was investigated. Ions extracted from a metal vapor vacuum arc (MEVVA) are sourced with 100keV energy and a dose range from 0.2×1017 to 2.0×1017ions·cm-2. The saturation dose of Cu implantation in AISI420 SS and Cu surface concentration were calculated at the energy of 100keV. The effect of dose on the antibacterial activity was analyzed. Results of antibacterial test show that the saturation dose is the optimum implantation dose for best antibacterial activity, which is above 99% against both Escherichia coli and Staphylococcus aureus. Novel phases such as Fe4Cu3 and Cu9.9Fe0.1 were found in the implanted layer by glancing angle X-ray diffraction (GXRD). The antibacterial activity of AISI420 SS attributes to Cu-contained phase.
文摘Two binuclear copper(I) complexes with novel structures and novel bonding,Cu_2(Ph_2PCH_2PPh_2)Cl_2 (Ph_2PCH_2PPh_2=dppm) and Cu_2(Ph_2P-CH_2CH_2PPh_2)Cl_2 (Ph_2PCH_2CH_2PPh_2=dppe), were prepared and characterized through elemental analyses, ICP, IR(4000-200 cm^(-1), CsI disc.), ^(31)P-NMR spectra. Their electronic conductivities, oxidation and reduction potentials were measured. Preliminary studies show that both of the two complexes have chlorobridging and phosphorus-bridging structures.
基金This work was supported by National Key Lab of Coordination Chemistry at Nanjing University Henan Natural Science Foundation.
文摘Binuclear Cu(Ⅰ) complex [Cu(dppm)(NO_3)]2 (dppm=Ph_2PCH_2PPh_2) and mononuclear Cu(Ⅰ) complex [Cu(dppe)(NO_3)] (dppe=Ph_2PCH_2CH_2PPh_2) have been synthesized by the ligand-reduction reaction of cupric nitrate with dppm and dppe in methanol and characterized by means of ICP, elemental analyses, molecular weight determination, TG, ^(31)P-NMR, IR and Raman spectra; their electronic conductivities and CV waves have also been measured. Results show that dppm coordinates to the Cu(Ⅰ) atoms as a bridging bidentate ligand and dppe as a chelating bidentate ligand, (NO_3)^(-1) behaves as a chelating bidentate ligand in both of the newly prepared complexes.
文摘In conditions of monochromatic excitation (λexc=337.1), the spectral dependence of the efficiency of fluorescence quenching αλ of humic acids samples by Cd2+ and Cu2+ ions was studied. The difference of αλ dependencies for these ions was established. In the spectral range 350 - 650 nm, changes of the αλ for Cd2+ ion are markedly different from the magnitude for changes αλ, which occur for ion Cu2+. The interpretation of mismatch dependences obtained αλ ions Cd2+ and Cu2+ is carried out within the concept of the availability of different sites, due to the difference in ionic radii (0.108 nm and 0.08 nm for Cd2+ and Cu2+, respectively).
文摘A new near-infrared fluorophore 2-(2-Aminoethyl) pyridine-tricarbocyanine (1) was rationally designed and synthe-sized as a fluorescent probe for detection of Cu2+ with high selectivity. The response of Probe 1 is based on the fluorescence quenching upon binding to Cu2+. The sensing performance of the proposed Cu2+-sensitive Probe 1 was then investigated. The probe can be applied to the quantification detection of Cu2+ with a linear concentration range covering from 4.8 × 10-7 to 1.6 × 10-4 mol/L and a detection limit of 9.3 × 10-8 mol/L. The experimental results showed that the response of 1 to Cu2+ was independent of pH in medium condition (pH 6.0-8.0), and exhibited excellent selectivity towards Cu2+ over other common metal cations.
基金This work was financially supported by the National Natural Science Foundation (No.10574106), the Science & Technology Plan of Guangdong Province (No.2003C105005) and the Scientific Research Foundation for the Returned Overseas Chinese Scholars of Chinese State Education Ministry (No.(2004)176).
文摘Cu2ZnSnS4 (CZTS) thin films were successfully prepared by sulfurization of ion bean sputtered precursors on soda-lime glass substrate. The single phase of stannite-type structure CZTS films were obtained as revealed in EDS and XRD analysis when the ratios of the constituents of CZTS thin films are close to stoichiometric by optimizing the conditions of precursor preparation and sulfurization. A low sheet resistivity as about 0.156 Ω·cm and a high absorption coefficient as 1×104 cm-1 were achieved in this method by Hall effect measurements and UV-VIS spectrophotometer. The optical band-gap energy of the CZTS sample is about 1.51 eV, which is very close to the optimum value for a solar-cell absorber.
基金Project(2004CB619205)supported by the National Basic Research Program of ChinaProject(50674102)supported by the National Natural Science Foundation of ChinaProject(2007AA060902)supported by High-tech Research and Development Program of China
基金Supported by the National Natural Science Foundation of China (No. 10975020)Key Laboratory of BeamTechnology and Material Modification of Ministry of Education, Beijing Normal University
文摘Highly oxidation. SEM analysis ordered anatase titania nanotube method was used to characterize arrays （TINT） were fabricated by anodic the morphology of the prepared samples. TiNT samples doped with Cu ions were prepared by home-made Metal Vapor Vacuum Arc ions sources （MEVVA, BNU, China） implanter. Photo-electric response and methyl orange decomposition ability of implanted samples under UV and visible light were tested, and the results indicated that the performance of Cu/TiNT enhanced significantly under visible light; it was noteworthy that the photocurrent density of A-Cu/TiNT was 0.102 mA/cm^2, which was 115 times that of pure TINT, and degradation ability of TiNT also strongly enhanced under visible light. In a word, the absorption spectrum of implanted anatase titania shifted to a longer wavelength region. Theoretic study on Cu-doped anatase based on density functional theory was carried out in this paper to validate the experiment results. The calculation results are depicted as follows： Intermittent energy band appeared around the Fermi energy after doping with Cu metal, the width of which was 0.35 eV and the location of valence and conduction bands shifted to the lower energy level by 0.22 eV; more excitation and jump routes were opened for the electrons. The narrowed band gaps allowed the photons with lower energy （at longer wavelength, such as visible light） to be absorbed, which accorded well with the experimental results.
基金supported by the National Research Foundation (NRF) grants funded by the Korean government (no.NRF-20110030256, NRF-2017R1A2B2011066 and NRF-2016M3A7B4910618)funded by the Saudi Aramco-KAIST CO2 Management Center
文摘In this paper, we report photoelectrochemical（PEC） conversion of carbon dioxide（CO_2） using photocathodes based on Cu_2O nanowires（NWs） overcoated with Cu~＋-incorporated crystalline TiO_2（TiO_2–Cu~＋ ）shell. Cu_2O NW photocathodes show remanent photocurrent of 5.3% after 30 min of PEC reduction of CO_2.After coating Cu_2O with TiO_2–Cu~＋ overlayer, the remanent photocurrent is 27.6%, which is an increase by5.2 fold. The charge transfer resistance of Cu_2O/TiO_2–Cu~＋ is 0.423 k/cm2, whereas Cu_2O photocathode shows resistivity of 0.781 k/cm2 under irradiation. Mott–Schottky analysis reveals that Cu~＋ species embedded in TiO_2 layer is responsible for enhanced adsorption of CO_2 on TiO_2 surface, as evidenced by the decrease of capacitance in the Helmholtz layer. On account of these electrochemical and electronic effects by the Cu~＋ species, the Faradaic efficiency（FE） of photocathodes reaches as high as 56.5% when TiO_2–Cu~＋ is added to Cu_2O, showing drastic increase from 23.6% by bare Cu_2O photocathodes.
文摘A novel thermally induced graft polymerization technique was used to modify a polyvinylidene fluoride （PVDF） hollow fibre microfiltration membrane. An artificial neural network （ANN） was applied to optimize the prepared condition of the membrane. The optimized dosing of acrylic acid （AA）, acrylamide （AM）, N, N＇- methylenebisacrylamide （NMBA） and potassium persulphate （KSP） designed by ANN was that AA was 40.63 ml/L; AM acted as 6.25 g/L; NMBA was 1.72 g/L and KSP was 1.5 g/L, respectively. The thermal stability of the PVDF modified hollow fibre membrane （PVDF-PAA） was investigated by thermogravimetric （TG） and differential scanning calorimetry （DSC） analysis. The polycrystallinity of the PVDF-PAA membrane was evaluated by X-ray diffraction （XRD） analysis. The complex formation of the modified membrane was ascertained by Fourier transform infrared spectroscopy （FTIR）. The morphology of the PVDF-PAA membrane was studied by environmental scanning electron microscopy （ESEM）. The surface compositions of the membrane were analyzed by X-ray photoelectron spectroscopy （XPS）. The adsorption capacity of Cu^2＋ ion on the PVDF-PAA hollow fibre membrane was also investigated.
基金Supported by the Post-doctoral Foundation of China
文摘1 INTRODUCTIONKnowledge of the basic transport phenomena of ions in an ion exchange membrane isimportant for the application of such a membrane.Various studies on the developmentof mathematical models for predicting and correlating membrane transport rate havebeen published in recent years.More exact estimation of the diffusion coefficientshas been the subject of chief concern in many of these papers.For a bi-ionic systemwith the same valence,Sato et al.gave a method for estimating diffusion coefficients
