From the measured phase diagram data and experimental thermochemical properties, the DyCl3-KCl and DyCl3-CaCl2 phase diagrams were optimized and calculated by the CALPHAD technique. The Gibbs energies of liquid phase ...From the measured phase diagram data and experimental thermochemical properties, the DyCl3-KCl and DyCl3-CaCl2 phase diagrams were optimized and calculated by the CALPHAD technique. The Gibbs energies of liquid phase in the two systems has been optimized and calculated by new modified quasi-chemical model in the pair-approximation for short-range ordering, and a series of thermodynamic functions has also been optimized based on an interactive computer-assisted analysis. The results showed that the calculated phase diagrams and thermodynamic data were serf-consistent.展开更多
It was found that silver nanoparticles could strongly enhance the chemiluminescence (CL) of the luminol-KIO4 system in the presence of Co2+. The most intensive CL signals were obtained with silver nanoparticles in dia...It was found that silver nanoparticles could strongly enhance the chemiluminescence (CL) of the luminol-KIO4 system in the presence of Co2+. The most intensive CL signals were obtained with silver nanoparticles in diameter of 22 nm. The studies of UV-visible spectra and CL spectra were carried out to explore the possible CL enhancement mechanism. Moreover, the influences of 17 amino acids and 25 organic compounds on the luminol-KIO4-Co2+-Ag NPs CL system were studied by a flow injection procedure, which led to an effective method to detect these compounds.展开更多
The water-soluble CdS nanoparticles were synthesized in aqueous solution. A novel fluorescence resonance energy transfer （FP, ET） system with CdS nanoparticles as energy donors and 3,3＇-diethyl-oxadicarbocyanine io...The water-soluble CdS nanoparticles were synthesized in aqueous solution. A novel fluorescence resonance energy transfer （FP, ET） system with CdS nanoparticles as energy donors and 3,3＇-diethyl-oxadicarbocyanine iodide （DOCAI） dyes as energy accepter has been developed.展开更多
A soluble, poly（ethylene glycol）-supported piperazine catalyst was prepared. This soluble catalyst efficiently catalyzes the Knoevenagel condensation of various aromatic aldehydes with diethyl malonate or ethyl acet...A soluble, poly（ethylene glycol）-supported piperazine catalyst was prepared. This soluble catalyst efficiently catalyzes the Knoevenagel condensation of various aromatic aldehydes with diethyl malonate or ethyl acetoacetate in a homogeneous phase to afford the desired alkenes in good purity and yield with a facile work-up process. It was found that the polymer reagent could be repeatedly used at least four times without the too much loss of activity. The catalyst has shown a good activity, stability, and recycling capability.展开更多
Inorganic anions such as phosphates and carbonates are essential in the natural system and it is important for the detec-tion of such species.In this work,the fluorescence sensing capacity of Zr(IV)framework with an a...Inorganic anions such as phosphates and carbonates are essential in the natural system and it is important for the detec-tion of such species.In this work,the fluorescence sensing capacity of Zr(IV)framework with an amino-functional group,namely UiO-66-NH_(2),towards specific inorganic anions was investigated in aqueous media.The results revealed that the fluorescence emission intensity of UiO-66-NH2 could be strongly enhanced by phosphate and carbonate anions including HPO_(4)^(2-),H_(2)PO_(4)^(-),PO_(4)^(3-),P_(2)O_(7)^(4-),HCO_(3)^(-)and CO_(3)^(2-),implying its sensing capacity towards phosphate and carbonate anions.Furthermore,fluorescence titration experiments exhibit that the emission intensity enhancement ratio depends linearly on the concentration of anions,suggesting the possibility of quantitative detection of these anions.Further studies suggest that the sensing of UiO-66-NH,towards HPO_(4)^(2-)/PO_(4)^(3-)/P_(2)O_(4)^(-)/HCO_(3)^(-)/CO_(2)-could be ascribed to the collapse of the framework,while that for H_(2)PO_(4)-could be attributed to the adsorption of H,PO4-by UiO-66-NH2 with hydrogen bonding interactions between H,PO4-and the amino group of UiO-66-NH_(2) supported by the different fluorescence response of UiO-66 and UiO-66-NH,towards the anions.展开更多
Zn（OH）F microbesoms have been synthesized on a large scale by a facile solution-based method using polymer as crystal growth modifier. The obtained products were characterized by X-ray powder diffraction （XRD）, X-...Zn（OH）F microbesoms have been synthesized on a large scale by a facile solution-based method using polymer as crystal growth modifier. The obtained products were characterized by X-ray powder diffraction （XRD）, X-ray photoelectron spectroscopy （XPS）, and scanning electron microscopy （SEM）. The effects of modifier polyacryla- mide （PAM）, reaction time, concentrations of NaF on the morphology and size of the product were studied. The resuits revealed that the Zn（OH）F microbesom had orthorhombic structures. Experimental conditions had all influence on the shape and size of the final products, but polymer PAM played the key role in formation of the Zn（OH）F microbesom. This novel structures exhibited good UV photocatalytic abilities,展开更多
The treatment ofwastewater that includes toxic organic pollutants such as dyes, phenoaniline, phenols and their derivatives is still a challenge due to their biorecalcitrant and acute toxicity to the widespread accept...The treatment ofwastewater that includes toxic organic pollutants such as dyes, phenoaniline, phenols and their derivatives is still a challenge due to their biorecalcitrant and acute toxicity to the widespread acceptance of water recycling. Three-dimensional （3D） Bi2WO6 microsphere was synthesized by the hydrothermal method using Bi（NO3）3 and Na2WO4 as raw materials. This structure exhibits high photocatalytic activity for the dyes, toxic organic compounds. The degradation of methlyene blue is 100% in 30 min, 4-nitrylphenol is 95% in 60min and p-nitrylphenol is 95% in 75min in ultraviolet （UV） light irradiation. 3D Bi2WO6 microsphere is also a good photocatalyst to treat the printing and dyeing sewage, and exhibits high repeatability. After being used the 20th time, Bi2WO6 still has high activity to degrade the printing and dyeing sewage, which is very important for a photocatalyst to be used in industry. This study will pave a new way to treat industry wastewater.展开更多
A novel flow injection procedure has been developed for the determination of gallic acid based on the en- hancement function for luminol-AgNO3-Ag NPs chemiluminescence （CL） system by gallic acid. The enhancement mec...A novel flow injection procedure has been developed for the determination of gallic acid based on the en- hancement function for luminol-AgNO3-Ag NPs chemiluminescence （CL） system by gallic acid. The enhancement mechanism was proposed for the reinforcing effect of the gallic acid on the CL system. The UV-vis absorption spectrum and CL emission spectrum were applied to confirm the mechanism. The method is simple, rapid and sen- sitive with a detection limit of 5 × 10^-10 g.mL-l and a linear range of 8.0 × 10^-10- 1.0 × 10-7 g.mL-1. The relative standard deviation （RSD） is 1.3% for eleven measurements of 5 × 10^-8 g-mL-1 gallic acid. The method has been successfully applied to the determination of gallic acid in Chinese proprietary medicine--Jianmin Yanhou tablets and synthesized samples.展开更多
A practical and efficient liquid-phase synthesis of 1,2,3-triazoles using poly（ethylene glycol） as support in aqueous solution was described. The title compounds, 1,2,3-triazoles 5 were obtained by a one-pot three-c...A practical and efficient liquid-phase synthesis of 1,2,3-triazoles using poly（ethylene glycol） as support in aqueous solution was described. The title compounds, 1,2,3-triazoles 5 were obtained by a one-pot three-component 1,3-dipolar cycloaddition reaction in middle yields. In addition, a series of unexpected products 7 of Sonogashira reaction were also formed under the same condition.展开更多
1,2-（1-Acridin-10＇-yl-2-aza-2-methylprop-1,3-ylene）fullerene was synthesized firstly and characterized by UV-Vis, ^1H NMR, ^13C NMR and electrospray ionization mass spectroscopy, which is capable of forming a stabl...1,2-（1-Acridin-10＇-yl-2-aza-2-methylprop-1,3-ylene）fullerene was synthesized firstly and characterized by UV-Vis, ^1H NMR, ^13C NMR and electrospray ionization mass spectroscopy, which is capable of forming a stable complex with zinc tetraphenylporphyrin via the axial ligation. The steady state fluorescence studies show efficient quenching of the zinc tetraphenylporphyrin emission upon axial coordination of acridine attached to C60.展开更多
The preparation of a glassy carbon electrode modified by CeO2 nanoparticles was described, which was characterized by cyclic voltammetry and electrochemical impedance spectroscopy. In pH 6.0 buffer, the CeO2 nanoparti...The preparation of a glassy carbon electrode modified by CeO2 nanoparticles was described, which was characterized by cyclic voltammetry and electrochemical impedance spectroscopy. In pH 6.0 buffer, the CeO2 nanoparticle modified electrode （CeO2 NP/GC） gave an excellent electrocatalytic activity for the oxidation of uric acid （UA）. The catalytic current of UA versus its concentration had a good linear relation in the range of 2.0 × 10^-7-5.0 × 10^- 4 mol/L, with the correlation coefficient of 0.9986 and detection limit of 1.0 ×10^-7 mol/L. The modified electrode can be used for the determination of UA in urine, which can tolerate the interference of ascorbic acid up to 1000-fold. The method was simple, quick and sensitive.展开更多
Vesicular lithium vanadium phosphate/carbon hollow mesoporous microspheres were fabricated using a facile polyvinylpyrrolidone-assisted aerosol-spray-assisted method and subsequent heat-treatment. While changing the c...Vesicular lithium vanadium phosphate/carbon hollow mesoporous microspheres were fabricated using a facile polyvinylpyrrolidone-assisted aerosol-spray-assisted method and subsequent heat-treatment. While changing the content of polyvinylpyrrolidone, we found that carbon content was adjustable on the surface of lithium vanadium phosphate. By optimizing the carbon content among the composites, the electrochemical performance can be enhanced significantly. The results of electrochemical performance tests suggested that the samples exhibited good cycle performance and high discharge capability in the voltages between 3.0-4.8 V. The observed excellent electrochemical performances could be attributed to the proper content of carbon coating and the vesicular hollow mesoporous microsphere structure, increasing the transmission rate of lithium ions and reducing the structural change during charging and discharging effectively.展开更多
Porous hollow Co3O4 microspheres have been synthesized from a mixed cobalt nitrate and urea solution through spray pyrolysis followed by calcination at 600 ℃ in air. This porous hollow Co3O4 is assembled by nanoparti...Porous hollow Co3O4 microspheres have been synthesized from a mixed cobalt nitrate and urea solution through spray pyrolysis followed by calcination at 600 ℃ in air. This porous hollow Co3O4 is assembled by nanoparticles and exhibits variable porosity depending on the amount of gas in the system. In pyrolysis process, urea continuously decomposes into gaseous components, which act as a template to control the porous structure. The amount of gas escaping from precursor droplets can directly influence the porosity of the microspheres and the size of the nanoparticles controlled by the ratio of urea to cobalt nitrate. Electrochemical measurements show that the performance of the porous hollow Co3O4 microspheres is related to the porosity and size of the nanopartides. The sample with optimal porosity delivers a high first charge capacity of 1,417.9 mAh·g^-1 at 0.2C （1C = 890 mA·g^-1）, and superior charge cycle performance of 1,012.7 mAh.g-1 after 100 cycles. In addition, the optimized material displays satisfactory rate performance of 1,012.4 mAh.g-1 at 1C after 50 cycles and 881.3 mAh·g^-1 at 2C after 300 cycles. Superior charge/discharge capacity, excellent rate performance and high yield achieved in this study is promising for the development of high-performance Co3O4 anode materials for lithium-ion batteries.展开更多
Bi2WO6 microstructures were synthesized through hydrothermal process and Ag@Bi2WO6 composites were synthesized by simple UV light irradiation for 5 rain using Bi2WO6 and AgNO3 as raw materials. Ag@BizWO6 composites we...Bi2WO6 microstructures were synthesized through hydrothermal process and Ag@Bi2WO6 composites were synthesized by simple UV light irradiation for 5 rain using Bi2WO6 and AgNO3 as raw materials. Ag@BizWO6 composites were characterized by X-ray powder diffraction （XRD）, field-emission scanning electron microscopy （FE-SEM）, and UV-Vis absorption spectrum （UV-Vis）. Few Ag deposited on the Bi2WO6 leads to an increase in photocatalytic activity, which clearly indicates that the recombination of photogenerated charge carrier between the hybrid orbital of Bi6s and O2p （valence band） to the empty W5d orbital is inhibited greatly in the Ag@Bi2WO6 composite. In addition, a few H2O2 will greatly enhance photocatalytic activity of Ag@BizWO6, and the proper reason is discussed.展开更多
Multicolor luminescent rare-earth ion-doped Y2O3 nanocrystals （NCs） were prepared by a solvethermal method. The as-synthesized NCs yielded nanosheets, nanowires （NWs） and nanorods （NRs） with the increase of alka...Multicolor luminescent rare-earth ion-doped Y2O3 nanocrystals （NCs） were prepared by a solvethermal method. The as-synthesized NCs yielded nanosheets, nanowires （NWs） and nanorods （NRs） with the increase of alkali （NaOH） in oleic acid system. Moreover, Y203 nanowires with controllable size have also been obtained. After sintering, the PL intensity of Y2O3：Ln3＋ nanocrystals increased with the changed morphology of the precursor, that is, Y（OH）3 nanocrystals. Both downconversion （red emission for Y2O3：Eu3＋ and green emission for Y2O3：Tb3＋） and upconversion （red emission for Y2O3：Yb/Er3＋） luminescence of the as-prepared nanocrystals have been demonstrated in this work. We also found that the PL intensity of Y2O3：Ln3＋ NCs dispersed in polar solvent was stronger than that in nonpolar solvent. Their up/downconversion fluorescence and controllable morphology might promise further fundamental research and biochemistry such as nanoscale optoelectronics, nanolasers, and ultrasensitive multicolor biolables.展开更多
Ni（OH）2 nanoflowers were synthesized by a simple and energy-efficient wet chemistry method. The product was characterized by scanning electron microscopy （SEM） and X-ray powder diffraction （XRD）. Then Ni（OH）2 ...Ni（OH）2 nanoflowers were synthesized by a simple and energy-efficient wet chemistry method. The product was characterized by scanning electron microscopy （SEM） and X-ray powder diffraction （XRD）. Then Ni（OH）2 nanoflowers attached multi-walled carbon nanotubes （MWCNTs） modified glassy carbon electrodes （GCE） were proposed （MWCNTs/Ni（OH）2/GCE） to use as electrochemical sensor to detect hydrogen peroxide. The results showed that the synergistic effect was obtained on the MWCNTs/Ni（OH）2/GCE whose sensitivity was better than that of Ni（OH）2/GCE. The linear range is from 0.2 to 22 mmol/L, the detection limit is 0.066 mmol/L, and the re- sponse time is 〈5 s. Satisfyingly, the MWCNTs/Ni（OH）2/GCE was not only successfully employed to eliminate the interferences from uric acid （UA）, acid ascorbic （AA）, dopamine （DA）, glucose （GO） but also NO2 during the detection. The MWCNTs/Ni（OH）z/GCE allows highly sensitive, excellently selective and fast amperometric sensing of hydrogen peroxide and thus is promising for the future development of hydrogen peroxide sensors.展开更多
基金Project supported by Key Item Faundation of Anhui MunicipalCommission of Education (Grant No .2005KJ016ZD)
文摘From the measured phase diagram data and experimental thermochemical properties, the DyCl3-KCl and DyCl3-CaCl2 phase diagrams were optimized and calculated by the CALPHAD technique. The Gibbs energies of liquid phase in the two systems has been optimized and calculated by new modified quasi-chemical model in the pair-approximation for short-range ordering, and a series of thermodynamic functions has also been optimized based on an interactive computer-assisted analysis. The results showed that the calculated phase diagrams and thermodynamic data were serf-consistent.
文摘It was found that silver nanoparticles could strongly enhance the chemiluminescence (CL) of the luminol-KIO4 system in the presence of Co2+. The most intensive CL signals were obtained with silver nanoparticles in diameter of 22 nm. The studies of UV-visible spectra and CL spectra were carried out to explore the possible CL enhancement mechanism. Moreover, the influences of 17 amino acids and 25 organic compounds on the luminol-KIO4-Co2+-Ag NPs CL system were studied by a flow injection procedure, which led to an effective method to detect these compounds.
基金This work was supported by the National Natural Science Foundation of China(No.20575001)the Fund of the Education Department of Anhui Province(No.2006KJ006TD)+1 种基金the education Commission Natural Science Foundation of Anhui Province(No.2005KJ017ZD)the Science Foundation of the Education Department of Anhui Province for Young Teacher(No.2006jq1050zd).
文摘The water-soluble CdS nanoparticles were synthesized in aqueous solution. A novel fluorescence resonance energy transfer （FP, ET） system with CdS nanoparticles as energy donors and 3,3＇-diethyl-oxadicarbocyanine iodide （DOCAI） dyes as energy accepter has been developed.
基金Supported by the National Natural Science Foundation of China(No.20872001)the Natural Science Foundation of Education Administration of Anhui Province,China(No.KJ2008A064)
文摘A soluble, poly（ethylene glycol）-supported piperazine catalyst was prepared. This soluble catalyst efficiently catalyzes the Knoevenagel condensation of various aromatic aldehydes with diethyl malonate or ethyl acetoacetate in a homogeneous phase to afford the desired alkenes in good purity and yield with a facile work-up process. It was found that the polymer reagent could be repeatedly used at least four times without the too much loss of activity. The catalyst has shown a good activity, stability, and recycling capability.
基金the National Natural Science Foundation of China (grant No.22171131) for financial support of this worksupported by a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Inorganic anions such as phosphates and carbonates are essential in the natural system and it is important for the detec-tion of such species.In this work,the fluorescence sensing capacity of Zr(IV)framework with an amino-functional group,namely UiO-66-NH_(2),towards specific inorganic anions was investigated in aqueous media.The results revealed that the fluorescence emission intensity of UiO-66-NH2 could be strongly enhanced by phosphate and carbonate anions including HPO_(4)^(2-),H_(2)PO_(4)^(-),PO_(4)^(3-),P_(2)O_(7)^(4-),HCO_(3)^(-)and CO_(3)^(2-),implying its sensing capacity towards phosphate and carbonate anions.Furthermore,fluorescence titration experiments exhibit that the emission intensity enhancement ratio depends linearly on the concentration of anions,suggesting the possibility of quantitative detection of these anions.Further studies suggest that the sensing of UiO-66-NH,towards HPO_(4)^(2-)/PO_(4)^(3-)/P_(2)O_(4)^(-)/HCO_(3)^(-)/CO_(2)-could be ascribed to the collapse of the framework,while that for H_(2)PO_(4)-could be attributed to the adsorption of H,PO4-by UiO-66-NH2 with hydrogen bonding interactions between H,PO4-and the amino group of UiO-66-NH_(2) supported by the different fluorescence response of UiO-66 and UiO-66-NH,towards the anions.
基金Project supported by the National Natural Science Foundation of China （No. 20671002） and Science and Technological Fund of Anhui Province for Outstanding Youth （No. 08040106834）.
文摘Zn（OH）F microbesoms have been synthesized on a large scale by a facile solution-based method using polymer as crystal growth modifier. The obtained products were characterized by X-ray powder diffraction （XRD）, X-ray photoelectron spectroscopy （XPS）, and scanning electron microscopy （SEM）. The effects of modifier polyacryla- mide （PAM）, reaction time, concentrations of NaF on the morphology and size of the product were studied. The resuits revealed that the Zn（OH）F microbesom had orthorhombic structures. Experimental conditions had all influence on the shape and size of the final products, but polymer PAM played the key role in formation of the Zn（OH）F microbesom. This novel structures exhibited good UV photocatalytic abilities,
文摘The treatment ofwastewater that includes toxic organic pollutants such as dyes, phenoaniline, phenols and their derivatives is still a challenge due to their biorecalcitrant and acute toxicity to the widespread acceptance of water recycling. Three-dimensional （3D） Bi2WO6 microsphere was synthesized by the hydrothermal method using Bi（NO3）3 and Na2WO4 as raw materials. This structure exhibits high photocatalytic activity for the dyes, toxic organic compounds. The degradation of methlyene blue is 100% in 30 min, 4-nitrylphenol is 95% in 60min and p-nitrylphenol is 95% in 75min in ultraviolet （UV） light irradiation. 3D Bi2WO6 microsphere is also a good photocatalyst to treat the printing and dyeing sewage, and exhibits high repeatability. After being used the 20th time, Bi2WO6 still has high activity to degrade the printing and dyeing sewage, which is very important for a photocatalyst to be used in industry. This study will pave a new way to treat industry wastewater.
文摘A novel flow injection procedure has been developed for the determination of gallic acid based on the en- hancement function for luminol-AgNO3-Ag NPs chemiluminescence （CL） system by gallic acid. The enhancement mechanism was proposed for the reinforcing effect of the gallic acid on the CL system. The UV-vis absorption spectrum and CL emission spectrum were applied to confirm the mechanism. The method is simple, rapid and sen- sitive with a detection limit of 5 × 10^-10 g.mL-l and a linear range of 8.0 × 10^-10- 1.0 × 10-7 g.mL-1. The relative standard deviation （RSD） is 1.3% for eleven measurements of 5 × 10^-8 g-mL-1 gallic acid. The method has been successfully applied to the determination of gallic acid in Chinese proprietary medicine--Jianmin Yanhou tablets and synthesized samples.
文摘A practical and efficient liquid-phase synthesis of 1,2,3-triazoles using poly（ethylene glycol） as support in aqueous solution was described. The title compounds, 1,2,3-triazoles 5 were obtained by a one-pot three-component 1,3-dipolar cycloaddition reaction in middle yields. In addition, a series of unexpected products 7 of Sonogashira reaction were also formed under the same condition.
基金Project supported by the National Natural Science Foundation of China （Nos. 20271002, 20490217）, Excellent Young Scholar Foundation （No. 04046065） and the Natural Science Foundation of Anhui Province （No. 00045122）, the Scientific Research Foundation for the Returned 0verseas Chinese Scholars and Excellent Young Teachers Program of the Ministry of Education of China, and the Education Department of Anhui Province （Nos. 2001KJ 115ZD, 2006KJ006TD）.Acknowledgement The authors wish to thank Hu Ji-Ping and Yang Gao- Sheng for their assistance with NMR.
文摘1,2-（1-Acridin-10＇-yl-2-aza-2-methylprop-1,3-ylene）fullerene was synthesized firstly and characterized by UV-Vis, ^1H NMR, ^13C NMR and electrospray ionization mass spectroscopy, which is capable of forming a stable complex with zinc tetraphenylporphyrin via the axial ligation. The steady state fluorescence studies show efficient quenching of the zinc tetraphenylporphyrin emission upon axial coordination of acridine attached to C60.
基金Project supported by the National Natural Science Foundation of China （No. 20675001）, Anhui Provincial Natural Science Foundation （No. 050460301） and the Science Foundation of Education 0ffice of Anhui Province （Nos. 2006kj145B and 2006kj119B）.
文摘The preparation of a glassy carbon electrode modified by CeO2 nanoparticles was described, which was characterized by cyclic voltammetry and electrochemical impedance spectroscopy. In pH 6.0 buffer, the CeO2 nanoparticle modified electrode （CeO2 NP/GC） gave an excellent electrocatalytic activity for the oxidation of uric acid （UA）. The catalytic current of UA versus its concentration had a good linear relation in the range of 2.0 × 10^-7-5.0 × 10^- 4 mol/L, with the correlation coefficient of 0.9986 and detection limit of 1.0 ×10^-7 mol/L. The modified electrode can be used for the determination of UA in urine, which can tolerate the interference of ascorbic acid up to 1000-fold. The method was simple, quick and sensitive.
基金supported by the National Natural Science Foundation of China (Nos.21871005 and 21471006)the Recruitment Program for Leading Talent Team of Anhui Province, the Program for Innovative Research Team of Anhui Education Committee, the Research Foundation for Science and Technology Leaders and Candidates of Anhui Province, the programs for Science and Technology Development of Anhui Province (No.1501021019)Anhui Normal University talent training program (No.2014rcpyl2).
文摘Vesicular lithium vanadium phosphate/carbon hollow mesoporous microspheres were fabricated using a facile polyvinylpyrrolidone-assisted aerosol-spray-assisted method and subsequent heat-treatment. While changing the content of polyvinylpyrrolidone, we found that carbon content was adjustable on the surface of lithium vanadium phosphate. By optimizing the carbon content among the composites, the electrochemical performance can be enhanced significantly. The results of electrochemical performance tests suggested that the samples exhibited good cycle performance and high discharge capability in the voltages between 3.0-4.8 V. The observed excellent electrochemical performances could be attributed to the proper content of carbon coating and the vesicular hollow mesoporous microsphere structure, increasing the transmission rate of lithium ions and reducing the structural change during charging and discharging effectively.
基金This work was supported by the National Natural Science Foundation of China （NSFC） （Nos. 21471006 and 21271009）, the Programs for Science and Technology Development of Anhui Province （No. 1501021019）, the Recruitment Program for Leading Talent Team of Anhui Province, the Program for Innova- tive Research Team of Anhui Education Committee, and the Research Foundation for Science and Technology Leaders and Candidates of Anhui Province.
文摘Porous hollow Co3O4 microspheres have been synthesized from a mixed cobalt nitrate and urea solution through spray pyrolysis followed by calcination at 600 ℃ in air. This porous hollow Co3O4 is assembled by nanoparticles and exhibits variable porosity depending on the amount of gas in the system. In pyrolysis process, urea continuously decomposes into gaseous components, which act as a template to control the porous structure. The amount of gas escaping from precursor droplets can directly influence the porosity of the microspheres and the size of the nanoparticles controlled by the ratio of urea to cobalt nitrate. Electrochemical measurements show that the performance of the porous hollow Co3O4 microspheres is related to the porosity and size of the nanopartides. The sample with optimal porosity delivers a high first charge capacity of 1,417.9 mAh·g^-1 at 0.2C （1C = 890 mA·g^-1）, and superior charge cycle performance of 1,012.7 mAh.g-1 after 100 cycles. In addition, the optimized material displays satisfactory rate performance of 1,012.4 mAh.g-1 at 1C after 50 cycles and 881.3 mAh·g^-1 at 2C after 300 cycles. Superior charge/discharge capacity, excellent rate performance and high yield achieved in this study is promising for the development of high-performance Co3O4 anode materials for lithium-ion batteries.
文摘Bi2WO6 microstructures were synthesized through hydrothermal process and Ag@Bi2WO6 composites were synthesized by simple UV light irradiation for 5 rain using Bi2WO6 and AgNO3 as raw materials. Ag@BizWO6 composites were characterized by X-ray powder diffraction （XRD）, field-emission scanning electron microscopy （FE-SEM）, and UV-Vis absorption spectrum （UV-Vis）. Few Ag deposited on the Bi2WO6 leads to an increase in photocatalytic activity, which clearly indicates that the recombination of photogenerated charge carrier between the hybrid orbital of Bi6s and O2p （valence band） to the empty W5d orbital is inhibited greatly in the Ag@Bi2WO6 composite. In addition, a few H2O2 will greatly enhance photocatalytic activity of Ag@BizWO6, and the proper reason is discussed.
文摘Multicolor luminescent rare-earth ion-doped Y2O3 nanocrystals （NCs） were prepared by a solvethermal method. The as-synthesized NCs yielded nanosheets, nanowires （NWs） and nanorods （NRs） with the increase of alkali （NaOH） in oleic acid system. Moreover, Y203 nanowires with controllable size have also been obtained. After sintering, the PL intensity of Y2O3：Ln3＋ nanocrystals increased with the changed morphology of the precursor, that is, Y（OH）3 nanocrystals. Both downconversion （red emission for Y2O3：Eu3＋ and green emission for Y2O3：Tb3＋） and upconversion （red emission for Y2O3：Yb/Er3＋） luminescence of the as-prepared nanocrystals have been demonstrated in this work. We also found that the PL intensity of Y2O3：Ln3＋ NCs dispersed in polar solvent was stronger than that in nonpolar solvent. Their up/downconversion fluorescence and controllable morphology might promise further fundamental research and biochemistry such as nanoscale optoelectronics, nanolasers, and ultrasensitive multicolor biolables.
文摘Ni（OH）2 nanoflowers were synthesized by a simple and energy-efficient wet chemistry method. The product was characterized by scanning electron microscopy （SEM） and X-ray powder diffraction （XRD）. Then Ni（OH）2 nanoflowers attached multi-walled carbon nanotubes （MWCNTs） modified glassy carbon electrodes （GCE） were proposed （MWCNTs/Ni（OH）2/GCE） to use as electrochemical sensor to detect hydrogen peroxide. The results showed that the synergistic effect was obtained on the MWCNTs/Ni（OH）2/GCE whose sensitivity was better than that of Ni（OH）2/GCE. The linear range is from 0.2 to 22 mmol/L, the detection limit is 0.066 mmol/L, and the re- sponse time is 〈5 s. Satisfyingly, the MWCNTs/Ni（OH）2/GCE was not only successfully employed to eliminate the interferences from uric acid （UA）, acid ascorbic （AA）, dopamine （DA）, glucose （GO） but also NO2 during the detection. The MWCNTs/Ni（OH）z/GCE allows highly sensitive, excellently selective and fast amperometric sensing of hydrogen peroxide and thus is promising for the future development of hydrogen peroxide sensors.
