| 1. |
- Chen, Hui, et al.
(author)
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Characterization of insolubilized humic acid and its sorption behaviors
- 2009
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In: Environmental Geology. - : Springer Science and Business Media LLC. - 0943-0105 .- 1432-0495. ; 57:8, s. 1847-1853
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Journal article (peer-reviewed)abstract
- Insolubilized humic acid (IHA) was prepared in the laboratory by heating approach. Through the comparison between the endothermic peaks, optimal heating temperature was determined to be 330A degrees C. The modified IHA then was characterized by TG-DTA, SEM, FTIR, element analysis, and nitrogen adsorption-desorption isotherms. The removal efficiency of p-nitrophenol from the aqueous solution by adsorption onto solid IHA surfaces was shown to be a function of pH, reaction temperature, and p-nitrophenol concentration. Adsorption equilibrium data satisfactorily fitted the Langmuir adsorption isotherm. Under a certain concentration range, the removal rate of p-nitrophenol at pH 3.5 could reach 24, 29, and 35 mg/g at a temperature of 25, 35, and 45 +/- 0.1A degrees C. The results suggest that IHA could play a role as a potential efficient absorbent to remove organic contaminants, e.g., utilized to purify water contaminated by organic compounds.
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| 2. |
- Cui, Jinxing, et al.
(author)
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Structural Deformation of Sm@C88under High Pressure
- 2015
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In: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 5
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Journal article (peer-reviewed)abstract
- We have studied the structural transformation of Sm@C88 under pressure up to 18 GPa by infraredspectroscopy combined with theoretical simulations. The infrared-active vibrational modes of Sm@C88 at ambient conditions have been assigned for the first time. Pressure-induced blue and red shiftsof the corresponding vibrational modes indicate an anisotropic deformation of the carbon cage uponcompression. We propose that the carbon cage changes from ellipsoidal to approximately sphericalaround 7 GPa. A smaller deformation of the carbon bonds in the area close to the Sm atom in thecage suggests that the trapped Sm atom plays a role in minimizing the compression of the adjacentbonds. Pressure induced a significant reduction of the band gap of the crystal. The HOMO-LUMOgap of the Sm@C88 molecule decreases remarkably at 7 GPa as the carbon cage is deformed. Also,compression enhances intermolecular interactions and causes a widening of the energy bands. Botheffects decrease the band gap of the sample. The carbon cage deforms significantly above 7 GPa,from spherical to a peanut-like shape and collapses at 18 GPa.
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| 3. |
- Cui, Wen, et al.
(author)
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Reversible pressure-induced polymerization of Fe(C5H5)(2) doped C-70
- 2013
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In: Carbon. - : Pergamon-Elsevier Science. - 0008-6223 .- 1873-3891. ; 62, s. 447-454
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Journal article (peer-reviewed)abstract
- High pressure Raman, IR and X-ray diffraction (XRD) studies have been carried out on C-70(Fe(C5H5)(2))(2) (hereafter, "C-70(Fc)(2)") sheets. Theoretical calculation is further used to analyze the Electron Localization Function (ELF) and charge transfer in the crystal and thus to understand the transformation of C-70(Fc)(2) under pressure. Our results show that even at room temperature dimeric phase and one dimensional (1D) polymer phase of C-70 molecules can be formed at about 3 and 8 GPa, respectively. The polymerization is found to be reversible Upon decompression and the reversibility is related to the pressure-tuned charge transfer, as well as the overridden steric repulsion of counter ions. According to the layered structure of the intercalated ferrocene molecules formed in the crystal, we suggest that ferrocene acts as not only a spacer to restrict the polymerization of C-70 molecules within a layer, but also as charge reservoir to tune the polymerization process. This supplies a possible way for us to design the polymerization of fullerenes at suitable conditions.
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| 4. |
- Wang, Lin, et al.
(author)
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Highly Enhanced Luminescence from Single-Crystalline C60·1m-xylene Nanorods
- 2006
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In: Chemistry of Materials. - : American Chemical Society (ACS). - 0897-4756 .- 1520-5002. ; 18:17, s. 4190-4194
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Journal article (peer-reviewed)abstract
- Single-crystalline C60â1m-xylene nanorods with a hexagonal structure were successfully synthesizedby evaporating a C60 solution in m-xylene at room temperature. The ratio of the length to the diameterof the nanorods can be controlled in the range of 10 to over 1000 for different applications. Thephotoluminescence (PL) intensity of the nanorods is about 2 orders of magnitude higher than that forpristine C60 crystals in air. Both UV and Raman results indicate that there is no charge transfer betweenC60 and m-xylene. It was found that the interaction between C60 and m-xylene molecules is of the vander Waals type. This interaction reduces the icosahedral symmetry of C60 molecule and induces strongPL from the solvate nanorods.
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