Herein,a one-pot chemical reduction method was reported to prepare folic acid(FA)-stabilized silver nanoclusters(FA@Ag NCs),in which FA,hydrazine hydrate,and silver nitrate were used as capping agent,reducing agent,an...Herein,a one-pot chemical reduction method was reported to prepare folic acid(FA)-stabilized silver nanoclusters(FA@Ag NCs),in which FA,hydrazine hydrate,and silver nitrate were used as capping agent,reducing agent,and precursor,respectively.Several technologies were employed to investigate the structures and optical properties of FA@Ag NCs,including transmission electron microscopy(TEM),X-ray photoelectron spectrometer(XPS),Fourier transform infrared spectrometer(FTIR),X-ray diffractometer(XRD),fluorescence spectrometer,and ultraviolet visible absorption spectrometer.FA@Ag NCs were suggested to be highly dispersed and spherical with a size of around 2.8 nm.Moreover,the maximum excitation and emission wavelengths of FA@Ag NCs were 370 and 447 nm,respectively.Under the optimal detection conditions,FA@Ag NCs could be used to effectively detect malachite green with the linear detection range of 0.5-200μmol·L^(-1).The detection limit was 0.084μmol·L^(-1).The fluorescence-quenching mechanism was ascribed to the static quenching.The detection system based on FA@AgNCs was successfully used for the detection of malachite green in actual samples with good accuracy and reproducibility.展开更多
In order to explore a novel and potential method using carbon nanotubes （CNTs） for controlling blue-green algal blooms efficiently in future, effects of single-walled carbon nanotubes （SWCNTs） on Microcystis aerug...In order to explore a novel and potential method using carbon nanotubes （CNTs） for controlling blue-green algal blooms efficiently in future, effects of single-walled carbon nanotubes （SWCNTs） on Microcystis aeruginosa growth control were investigated under lab cultured conditions. Related physiological changes were tested involving several important enzyme of antioxidant defense system （superoxide dismutase （SOD）, peroxidase （POD）, catalase （CAT）, malondiadehyde （MDA）, photosynthetic pigments, protein, soluble sugar and extracellular microcystin toxins （MC-LR））. Algal cell density was significantly inhibited by SWCNTs at high concentration （〉5.00 mg/L）, and the inhibition rate was dose-dependent. For treatment with 100 mg/L SWCNTs, the inhibitory rates even reached above 90%. 96 h IC50 was determined as 22 mg/L. Antioxidant enzyme activities were dramatically dropped with increasing lipid peroxidation at higher SWCNTs concentration, indicating intracellular generation of reactive oxygen species （ROS） and oxidative stress damage in algae. Reduction of photosynthetic pigments, soluble sugar and protein contents suggested that SWCNTs may severely ruin algal photosynthesis system, destroy the metabolism-related structure of cell, and thus lead to negative physiological status in M. aeruginosa. Besides, SWCNTs can effectively decrease the amount of extracellular microcystins in culture medium.展开更多
Ultrafine cube-shape Ce2Sn2O7 nanoparticles crystallized in pure pyrochlore phase with a size of about 10 nm have been successfully synthesized by a facile hydrothermal method.Conditional experiments have been conduct...Ultrafine cube-shape Ce2Sn2O7 nanoparticles crystallized in pure pyrochlore phase with a size of about 10 nm have been successfully synthesized by a facile hydrothermal method.Conditional experiments have been conducted to optimize the processing parameters including temperature,pH,reaction duration,precipitator types to obtain phase-pure Ce2Sn2O7.The crystal structure,morphology and sizes and specific surface area have been characterized by X-ray diffractometer(XRD),Raman spectrum,transmission electron microscope(TEM),high resolution transmission electron microscope(HRTEM),and Brunauer-Emmett-Teller(BET).The as-synthesized Ce2Sn2O7 ultrafine nanocubes have been evaluated as electrode materials for pseudo-capacitors and lithium ion batteries.When testing as supercapacitors,a high specific capacitance of 222 F/g at 0.1 A/g and a good cycling stability with a capacitance retention of higher than 86%after 5000 cycle have been achieved.When targeted for anode material for lithium ion batteries,the nanocubes deliver a high specific reversible capacity of more than 900 mA·h/g at 0.05C rate.The rate capability and cycling performance is also very promising as compared with the traditional graphite anode.展开更多
文摘Herein,a one-pot chemical reduction method was reported to prepare folic acid(FA)-stabilized silver nanoclusters(FA@Ag NCs),in which FA,hydrazine hydrate,and silver nitrate were used as capping agent,reducing agent,and precursor,respectively.Several technologies were employed to investigate the structures and optical properties of FA@Ag NCs,including transmission electron microscopy(TEM),X-ray photoelectron spectrometer(XPS),Fourier transform infrared spectrometer(FTIR),X-ray diffractometer(XRD),fluorescence spectrometer,and ultraviolet visible absorption spectrometer.FA@Ag NCs were suggested to be highly dispersed and spherical with a size of around 2.8 nm.Moreover,the maximum excitation and emission wavelengths of FA@Ag NCs were 370 and 447 nm,respectively.Under the optimal detection conditions,FA@Ag NCs could be used to effectively detect malachite green with the linear detection range of 0.5-200μmol·L^(-1).The detection limit was 0.084μmol·L^(-1).The fluorescence-quenching mechanism was ascribed to the static quenching.The detection system based on FA@AgNCs was successfully used for the detection of malachite green in actual samples with good accuracy and reproducibility.
基金Project(035703011) supported by the Scientific Research Double Support Program of SICAU,China
文摘In order to explore a novel and potential method using carbon nanotubes （CNTs） for controlling blue-green algal blooms efficiently in future, effects of single-walled carbon nanotubes （SWCNTs） on Microcystis aeruginosa growth control were investigated under lab cultured conditions. Related physiological changes were tested involving several important enzyme of antioxidant defense system （superoxide dismutase （SOD）, peroxidase （POD）, catalase （CAT）, malondiadehyde （MDA）, photosynthetic pigments, protein, soluble sugar and extracellular microcystin toxins （MC-LR））. Algal cell density was significantly inhibited by SWCNTs at high concentration （〉5.00 mg/L）, and the inhibition rate was dose-dependent. For treatment with 100 mg/L SWCNTs, the inhibitory rates even reached above 90%. 96 h IC50 was determined as 22 mg/L. Antioxidant enzyme activities were dramatically dropped with increasing lipid peroxidation at higher SWCNTs concentration, indicating intracellular generation of reactive oxygen species （ROS） and oxidative stress damage in algae. Reduction of photosynthetic pigments, soluble sugar and protein contents suggested that SWCNTs may severely ruin algal photosynthesis system, destroy the metabolism-related structure of cell, and thus lead to negative physiological status in M. aeruginosa. Besides, SWCNTs can effectively decrease the amount of extracellular microcystins in culture medium.
基金Project(JCYJ20170817110251498)supported by the Basic Research Project of the Science and Technology Innovation Commission of Shenzhen,ChinaProject(2016TQ03C919)supported by the Guangdong Special Support for the Science and Technology Leading Young Scientist,ChinaProjects(21603094,21703096)supported by the National Natural Science Foundation of China
文摘Ultrafine cube-shape Ce2Sn2O7 nanoparticles crystallized in pure pyrochlore phase with a size of about 10 nm have been successfully synthesized by a facile hydrothermal method.Conditional experiments have been conducted to optimize the processing parameters including temperature,pH,reaction duration,precipitator types to obtain phase-pure Ce2Sn2O7.The crystal structure,morphology and sizes and specific surface area have been characterized by X-ray diffractometer(XRD),Raman spectrum,transmission electron microscope(TEM),high resolution transmission electron microscope(HRTEM),and Brunauer-Emmett-Teller(BET).The as-synthesized Ce2Sn2O7 ultrafine nanocubes have been evaluated as electrode materials for pseudo-capacitors and lithium ion batteries.When testing as supercapacitors,a high specific capacitance of 222 F/g at 0.1 A/g and a good cycling stability with a capacitance retention of higher than 86%after 5000 cycle have been achieved.When targeted for anode material for lithium ion batteries,the nanocubes deliver a high specific reversible capacity of more than 900 mA·h/g at 0.05C rate.The rate capability and cycling performance is also very promising as compared with the traditional graphite anode.
