本文利用双色–光发射电子显微镜(Photoemission Electron Microscopy, PEEM)成像了电子束加工的金纳米环样品的等离激元近场分布。利用双色的实验方法有效地打开了双色量子通道,从而导致发射电子的非线性阶次从3.80降低到1.85,并且光...本文利用双色–光发射电子显微镜(Photoemission Electron Microscopy, PEEM)成像了电子束加工的金纳米环样品的等离激元近场分布。利用双色的实验方法有效地打开了双色量子通道,从而导致发射电子的非线性阶次从3.80降低到1.85,并且光辐射电子的产额显著增加。通过近场PEEM图像表明,由于存在缺陷激发的强烈干扰,掩盖了结构的场分布信息。进一步分析缺陷位置处电子非线性阶次,发现纳米环缺陷位置处电子的非线性阶次下降程度显著低于非缺陷处。双色PEEM成像的技术对于等离激元近场成像等相关研究的发展起到推动作用。展开更多
The graphene-gold nanoparticles composite film modified glassy carbon electrode （EG- AuNPs/GCE） was prepared by one-step coelectrodeposition and employed for determination of trace mercury in environmental water wit...The graphene-gold nanoparticles composite film modified glassy carbon electrode （EG- AuNPs/GCE） was prepared by one-step coelectrodeposition and employed for determination of trace mercury in environmental water with differential pulse stripping voltammetry. Such a nanostructured composite film combined with the advantages of gold nanoparticles and graphene, can greatly promote the electron-transfer process and increase accumulation abil-ity for Hg（Ⅱ）, leading to a remarkably improved sensitivity. The linear calibration curve ranged from 0.2 μg/L to 30 μg/L for Hg（Ⅱ） and the detection limit （S/N=3） was found to be 0.03 μg/L at a deposition time of 300 s. Moreover, the stablity of the as-prepared electrode and interferences from other substances were evaluated. The modified electrode was successfully applied to the direct detection of Hg（Ⅱ） in real water samples.展开更多
The synthesis of gold nanoparticles caped with visible light-responsible TiO2 nanoparticles. was prepared by using electrochemical Oxidation-Reduction Cycles （ORC） in 0.1 M HCI aqueous solution containing 60 mM visi...The synthesis of gold nanoparticles caped with visible light-responsible TiO2 nanoparticles. was prepared by using electrochemical Oxidation-Reduction Cycles （ORC） in 0.1 M HCI aqueous solution containing 60 mM visible light-responsible TiO2 nanoparticles. Firstly, an Au substrate was cycled in a deoxygenated aqueous solution containing 0.1 M HCI and 60 mM anatase TiO2 nanoparticles from -0.28 to ＋1.22 V vs Ag/AgCI at 500 mV/s with 25 scans. The durations at the cathodic and anodic vertexes are 10 and 5 s, respectively. After this process, Au-and TiO2-containing complexes were left in the solution. Then a Pt electrode immediately replaced the Au working electrode, and a cathodic overpotential of 0.6 V from the Open Circuit Potential （OCP） was applied under sonification to synthesize Au nanoparticles. Encouragingly, the prepared Au nanoparticles caped with visible light-responsible TiO2 nanoparticles are more active for the decomposition of formaldehyde than pure visible light-responsible TiO2 nanoparticles are in the same condition. After 5 days testing, the formaldehyde was decomposed ca. 35% in containing Au nanoparticles caped with visible light-responsible TiO2 nanoparticles, but the formaldehyde was decomposed only ca. 25% in containing pure visible light-responsible TiO2 nanoparticles.展开更多
This review summarizes the utilization of supported noble metal nanoparticles (such as Au/TiO2, Au/ZrO2, Ag/AgCl) as efficient photo/sono-catalysts for the selective synthesis of chemicals and degradation of environme...This review summarizes the utilization of supported noble metal nanoparticles (such as Au/TiO2, Au/ZrO2, Ag/AgCl) as efficient photo/sono-catalysts for the selective synthesis of chemicals and degradation of environmental pollutants. Supported noble metal nanoparticles could efficiently catalyze the conversion of solar energy into chemical energy. Under UV/visible light irradiation, important chemical transformations such as the oxidation of alcohols to carbonyl compounds, the oxidation of thiol to disulfide, the oxidation of benzene to phenol, and the reduction of nitroaromatic compounds to form aromatic azo compounds, are effectively achieved by supported noble metal nanoparticles. Under ultrasound irradiation, supported noble metal nanoparticles could efficiently catalyze the production of hydrogen from water. Moreover, various pollutants, including aldehydes, alcohols, acids, phenolic compounds, and dyes, can be effectively decomposed over supported noble metal nanoparticles under UV/visible light irradiation. Under ultrasound irradiation, pollutant molecules can also be completely degraded with supported noble metal nanoparticles as catalysts.展开更多
We have theoretically investigated the effect of the dielectric core and the dielectric embedding medium separately on the transmission spectra and plasmonic properties of coupled metallic nanotube arrays.It is found ...We have theoretically investigated the effect of the dielectric core and the dielectric embedding medium separately on the transmission spectra and plasmonic properties of coupled metallic nanotube arrays.It is found that the plasmonic properties of the nanotube arrays are strongly influenced by the presence of the dielectric which induces additional screening charges.We show that instead of one single photonic bandgap for the hollow nanotube arrays placed in air,an additional photonic bandgap arises from the presence of dielectric media in the transmission spectra.Based on the localized nature of the electric field distributions,we also clearly show the presence of the local plasmonic resonant modes that originate from multipolar plasmon polaritons in the cross section of these nanotube arrays,and that a large amount of opposing surface charges are built up in the gap between adjacent nanotubes.展开更多
Malignant tumors are complex organs consisting of tumor cells and their microenvironment. Increasing evidence has shown that the tumor microenvironment is critical to the initiation and progression of tumors. Rational...Malignant tumors are complex organs consisting of tumor cells and their microenvironment. Increasing evidence has shown that the tumor microenvironment is critical to the initiation and progression of tumors. Rational design of tumor therapies via targeting the tumor microenvironment to inhibit tumor growth is thus becoming a consensus strategy. Gd@C 82 (OH) 22 nanoparticles, as novel endohedral hydroxylated metallofullerenes, have been demonstrated to be a potent antitumor nanomedicine via targeting multiple factors in the tumor microenvironment. Gd@C 82 (OH) 22 nanoparticles possess excellent biocompatibility and remarkable antineoplastic activity, as a result not of direct tumor cytotoxicity but of their diverse biological effects, including antioxidation, immune activation, angiogenesis inhibition, imprisoning cancer cells, and reversal of drug-resistance. In this article, we summarize the unique nanoscale physiochemical properties and the antineoplastic activities of Gd@C 82 (OH) 22 nanoparticles, and focus on the mechanisms underlying their regulation of the tumor microenvironment.展开更多
文摘本文利用双色–光发射电子显微镜(Photoemission Electron Microscopy, PEEM)成像了电子束加工的金纳米环样品的等离激元近场分布。利用双色的实验方法有效地打开了双色量子通道,从而导致发射电子的非线性阶次从3.80降低到1.85,并且光辐射电子的产额显著增加。通过近场PEEM图像表明,由于存在缺陷激发的强烈干扰,掩盖了结构的场分布信息。进一步分析缺陷位置处电子非线性阶次,发现纳米环缺陷位置处电子的非线性阶次下降程度显著低于非缺陷处。双色PEEM成像的技术对于等离激元近场成像等相关研究的发展起到推动作用。
文摘The graphene-gold nanoparticles composite film modified glassy carbon electrode （EG- AuNPs/GCE） was prepared by one-step coelectrodeposition and employed for determination of trace mercury in environmental water with differential pulse stripping voltammetry. Such a nanostructured composite film combined with the advantages of gold nanoparticles and graphene, can greatly promote the electron-transfer process and increase accumulation abil-ity for Hg（Ⅱ）, leading to a remarkably improved sensitivity. The linear calibration curve ranged from 0.2 μg/L to 30 μg/L for Hg（Ⅱ） and the detection limit （S/N=3） was found to be 0.03 μg/L at a deposition time of 300 s. Moreover, the stablity of the as-prepared electrode and interferences from other substances were evaluated. The modified electrode was successfully applied to the direct detection of Hg（Ⅱ） in real water samples.
文摘The synthesis of gold nanoparticles caped with visible light-responsible TiO2 nanoparticles. was prepared by using electrochemical Oxidation-Reduction Cycles （ORC） in 0.1 M HCI aqueous solution containing 60 mM visible light-responsible TiO2 nanoparticles. Firstly, an Au substrate was cycled in a deoxygenated aqueous solution containing 0.1 M HCI and 60 mM anatase TiO2 nanoparticles from -0.28 to ＋1.22 V vs Ag/AgCI at 500 mV/s with 25 scans. The durations at the cathodic and anodic vertexes are 10 and 5 s, respectively. After this process, Au-and TiO2-containing complexes were left in the solution. Then a Pt electrode immediately replaced the Au working electrode, and a cathodic overpotential of 0.6 V from the Open Circuit Potential （OCP） was applied under sonification to synthesize Au nanoparticles. Encouragingly, the prepared Au nanoparticles caped with visible light-responsible TiO2 nanoparticles are more active for the decomposition of formaldehyde than pure visible light-responsible TiO2 nanoparticles are in the same condition. After 5 days testing, the formaldehyde was decomposed ca. 35% in containing Au nanoparticles caped with visible light-responsible TiO2 nanoparticles, but the formaldehyde was decomposed only ca. 25% in containing pure visible light-responsible TiO2 nanoparticles.
文摘This review summarizes the utilization of supported noble metal nanoparticles (such as Au/TiO2, Au/ZrO2, Ag/AgCl) as efficient photo/sono-catalysts for the selective synthesis of chemicals and degradation of environmental pollutants. Supported noble metal nanoparticles could efficiently catalyze the conversion of solar energy into chemical energy. Under UV/visible light irradiation, important chemical transformations such as the oxidation of alcohols to carbonyl compounds, the oxidation of thiol to disulfide, the oxidation of benzene to phenol, and the reduction of nitroaromatic compounds to form aromatic azo compounds, are effectively achieved by supported noble metal nanoparticles. Under ultrasound irradiation, supported noble metal nanoparticles could efficiently catalyze the production of hydrogen from water. Moreover, various pollutants, including aldehydes, alcohols, acids, phenolic compounds, and dyes, can be effectively decomposed over supported noble metal nanoparticles under UV/visible light irradiation. Under ultrasound irradiation, pollutant molecules can also be completely degraded with supported noble metal nanoparticles as catalysts.
基金the Excellent Doctorate Dissertation Foundation of Central South University (Grant No.2008yb039)the Postgraduate Innovative Project of Hunan Province (Grant No.CX2009B029)
文摘We have theoretically investigated the effect of the dielectric core and the dielectric embedding medium separately on the transmission spectra and plasmonic properties of coupled metallic nanotube arrays.It is found that the plasmonic properties of the nanotube arrays are strongly influenced by the presence of the dielectric which induces additional screening charges.We show that instead of one single photonic bandgap for the hollow nanotube arrays placed in air,an additional photonic bandgap arises from the presence of dielectric media in the transmission spectra.Based on the localized nature of the electric field distributions,we also clearly show the presence of the local plasmonic resonant modes that originate from multipolar plasmon polaritons in the cross section of these nanotube arrays,and that a large amount of opposing surface charges are built up in the gap between adjacent nanotubes.
文摘Malignant tumors are complex organs consisting of tumor cells and their microenvironment. Increasing evidence has shown that the tumor microenvironment is critical to the initiation and progression of tumors. Rational design of tumor therapies via targeting the tumor microenvironment to inhibit tumor growth is thus becoming a consensus strategy. Gd@C 82 (OH) 22 nanoparticles, as novel endohedral hydroxylated metallofullerenes, have been demonstrated to be a potent antitumor nanomedicine via targeting multiple factors in the tumor microenvironment. Gd@C 82 (OH) 22 nanoparticles possess excellent biocompatibility and remarkable antineoplastic activity, as a result not of direct tumor cytotoxicity but of their diverse biological effects, including antioxidation, immune activation, angiogenesis inhibition, imprisoning cancer cells, and reversal of drug-resistance. In this article, we summarize the unique nanoscale physiochemical properties and the antineoplastic activities of Gd@C 82 (OH) 22 nanoparticles, and focus on the mechanisms underlying their regulation of the tumor microenvironment.
