Xiaoqiang Sun

Changzhou University, Wujin, Jiangsu Sheng, China

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Publications (61)98.32 Total impact

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    ABSTRACT: The title compound, C17H17NO3, prepared by the condensation reaction of 2-(1,3-dioxan-2-yl)aniline and salicyl-aldehyde, has an E conformation about the C=N bond. The six-membered O-heterocycle adopts a chair conformation, with the bond to the aromatic ring located at its equatorial position. The dihedral angle between the aromatic rings is 36.54 (9)°. There is an intra-molecular N-H⋯O hydrogen bond forming an S(6) ring motif. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds, forming chains along the a-axis direction. Within the chains, there are C-H⋯π inter-actions involving adjacent mol-ecules.
    05/2015; 71(5):o357-o358. DOI:10.1107/S2056989015008051
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    ABSTRACT: The title compound, C26H22N4O5 (systematic name: methyl 2-eth-oxy-1-{4-[2-(5-oxo-4,5-di-hydro-1,2,4-oxa-diazol-3-yl)phenyl]benz-yl}-1H-1,3-benzo-diazole-7-carboxyl-ate ethyl acetate hemisolvate), was obtained via cyclization of methyl (Z)-2-eth-oxy-1-{(2'-(N'-hy-droxy-carbamimido-yl)-[1,1'-biphen-yl]-4-yl)meth-yl}-1H-benzo[d]imidazole-7-carboxyl-ate with diphen-yl carbonate. There are two independent mol-ecules (A and B) with different conformations and an ethyl acetate solvent mol-ecule in the asymmetric unit. In mol-ecule A, the dihedral angle between the benzene ring and its attached oxa-diazole ring is 59.36 (17); the dihedral angle between the benzene rings is 43.89 (15) and that between the benzene ring and its attached imidazole ring system is 80.06 (11)°. The corres-ponding dihedral angles in mol-ecule B are 58.45 (18), 50.73 (16) and 85.37 (10)°, respectively. The C-O-C-Cm (m = meth-yl) torsion angles for the eth-oxy side chains attached to the imidazole rings in mol-ecules A and B are 93.9 (3) and -174.6 (3)°, respectively. In the crystal, the components are linked by N-H⋯N and C-H⋯O hydrogen bonds, generating a three-dimensional network. Aromatic π-π stacking inter-actions [shortest centroid-centroid separation = 3.536 (3)Å] are also observed.
    02/2015; 71(Pt 2):o84-5. DOI:10.1107/S2056989014028023
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    ABSTRACT: The title compound, C19H16F4O4, was prepared by the condensation reaction of 2,6-di­fluoro­benzaldehyde and penta­erythritol. The whole mol­ecule is generated by twofold rotational symmetry. The two six-membered O-heterocycles adopt chair conformations through a shared spiro-carbon atom that is located on the crystallographic twofold rotation axis. In this conformation, the two aromatic rings are located at the equatorial positions of the O-heterocycles. The conformation of this doubly substituted tetra­oxa­spiro system is chiral. In the crystal, mol­ecules are linked by C-HO hydrogen bonds, forming layers parallel to (100). These layers are linked by C-HF hydrogen bonds into a three-dimensional structure.
    02/2015; 71(2):o127-o128. DOI:10.1107/S2056989015001206
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    ABSTRACT: We report a stable palladium/graphene (Pd/G) nanocomposite with differing Pd content for use in the catalytic hydrogenation of nitrophenols and nitrotoluenes. Various microscopic and spectroscopic techniques were employed to characterize the as-prepared catalysts. Catalytic hydrogenation reactions of nitrophenols were conducted in aqueous solution by adding NaBH4, while the nitrotoluene hydrogenation was carried out in methanol in the presence of H2 because of the poor solubility in water. The Pd/G hybrids exhibited much higher activity and higher stability than the commercial Pd/C. Due to the presence of a large excess of NaBH4 compared to p-nitrophenol, the kinetic data can be explained by the assumption of a pseudo-first-order reaction with regard to p-nitrophenol. The resulting high catalytic activity can be attributed to the graphene sheets’ strong dispersion effect for Pd nanoparticles and good adsorption ability for nitrobenzene derivatives via π-π stacking interactions. A plausible mechanism is proposed. Considering inductive and conjugation effects that may affect the reactions, the reactivity of nitrophenols in this study is expected to follow the order m-NP > o-NP > p-NP > 2,4-DNP > 2,4,6-TNP, which is in good agreement with the experimental results.
    Catalysis Science & Technology 01/2014; 4(6):1742. DOI:10.1039/c4cy00048j · 4.76 Impact Factor
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    ABSTRACT: Ultrafine Pt nanoparticles with an average diameter of only 1.7 nm are uniformly dispersed onto MnO2-functionalized graphene sheets by a facile and cost-effective method. In such a ternary Pt/MnO2/graphene sheets (Pt/MnO2/GS) nanohybrid, each component provides unique and critical function to achieve optimized utilization of metallic platinum, allowing it to express ultrahigh electrocatalytic activity ability in methanol oxidation (the forward anodic peak current density is up to 1224 mA mg(-1)) in comparison with Pt/graphene sheets (Pt/GS), Pt/Vulcan XC-72 (Pt/XC-72) and Pt/MnO2/XC-72 catalysts. This work could provide new insights into the fabrication of the next generation high-performance electrocatalyst and promote their practical application in fuel-cell technologies.
    Journal of Power Sources 10/2013; 239:189-195. DOI:10.1016/j.jpowsour.2013.03.133 · 6.22 Impact Factor
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    ABSTRACT: We designed the reduced graphene oxide (RGO)-based Ag@Ag3PO4 hetero-photocatalyst by coprecipitation and photoreduction. The graphene sheets are fully coated with Ag@Ag3PO4 nanocrystals with an average diameter of 200 nm. Ag@Ag3PO4/RGO hetero-photocatalyst showed strong absorbance in the visible region and low recombination rate of holes and electrons. Compared with Ag@Ag3PO4, Ag3PO4 and Ag3PO4/GO, Ag@Ag3PO4/RGO hetero-photocatalyst exhibited greatly enhanced photocatalytic activity under visible-light irradiation for the photodegradation of not only cationic dye (rhodamine B) but also anionic dye (methyl orange), which is usually difficult to be degraded over other catalysts. Moreover, the hetero-photocatalyst can be used repetitively with a high photocatalytic activity. The mechanism was explored and confirmed, showing that the improvements are attributed to the effective charge transfer from Ag3PO4 nanocrystals to RGO through Ag nanoparticles, which hinders the recombination of electron/hole pairs and the photocorrosion of Ag3PO4. This study could provide new insights in the design and fabrication of highly efficient visible-light-driven novel photocatalysts for solving energy and environmental problems.
    Powder Technology 09/2013; 246:278–283. DOI:10.1016/j.powtec.2013.05.034 · 2.27 Impact Factor
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    ABSTRACT: A straightforward strategy is designed for the fabrication of magnetically recyclable ternary titania–cobalt ferrite–polyaniline (P25-CoFe2O4-PANI) photocatalysts with differing P25/CoFe2O4 ratio. The pseudo-second-order and Langmuir models are found to be most suitable for describing the adsorption of methyl orange (MO) onto the photocatalysts. The photocatalytic activity of P25-CoFe2O4-PANI is evaluated by the degradation of various dyes under visible light irradiation, and the results show that the ternary P25-CoFe2O4-PANI photocatalyst exhibits high photocatalytic activity due to the good adsorption capacity of the hybrid and the introduction of P25, which can further improve the separation of the light-induced electron–hole pairs. The degradation of anionic dyes is much more effective than that of cationic dyes due to the negatively charged groups of anionic dyes undergo electrostatic attraction with the positively charged backbone of PANI, and such an effective adsorption helps in promoting the degradation.
    Industrial & Engineering Chemistry Research 07/2013; 52(30):10105–10113. DOI:10.1021/ie400739e · 2.24 Impact Factor
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    ABSTRACT: NiCo2O4 nanowires-loaded reduced graphene oxide composite (NiCo2O4@RGO) was prepared by a facile hydrothermal method without any surfactant. Hexamethylenetetramine was introduced as a structure directing and assembling agent to the synthesis of NiCo2O4 nanowires. NiCo2O4 nanowires with an average size of 80×10 nm2 are uniformly and densely dispersed on the graphene sheets. Cyclic voltammetry and galvanostatic charge–discharge measurements on NiCo2O4@RGO indicated a high specific capacitance of 737 F g−1 at a current density of 1 A g−1 and only 6% loss of the initial specific capacitance after 3000 charge/discharge cycles at 4 A g−1 in 2 M KOH electrolyte, which is valuable for practical application in supercapacitors.
    Materials Letters 05/2013; 98:164–167. DOI:10.1016/j.matlet.2013.02.035 · 2.27 Impact Factor
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    ABSTRACT: We reported a facile co-precipitation method to prepare a highly active Fe3O4@graphene oxide (Fe3O4@GO) composite catalyst, which was fully characterized by means of X-ray diffraction (XRD), Fourier transformed infrared (FTIR) spectroscopy, transmission electron microscopy (TEM) and N2 adsorption–desorption measurements. The results demonstrated that the Fe3O4 nanoparticles (Fe3O4 NPs) with a small diameter of around 12 nm were densely and evenly deposited on the graphene oxide (GO) sheets. The as-prepared Fe3O4@GO composite was explored as a catalyst to reduce a series of nitroarenes for the first time, which exhibited a great activity with a turnover frequency (TOF) of 3.63 min−1, forty five times that of the commercial Fe3O4 NPs. The dosages of catalyst and hydrazine hydrate are both less than those reported. Furthermore, the composite catalyst can be easily recovered due to its magnetic separability and high stability.
    Materials Research Bulletin 05/2013; 48(5):1885–1890. DOI:10.1016/j.materresbull.2013.01.038 · 2.29 Impact Factor
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    ABSTRACT: Multiple valence silver nanoparticles with irregular shape were anchored on reduced graphene oxide sheets by light irradiation. The characterization analysis revealed silver nanoparticles with different valences were uniformly attached on the surface of reduced graphene oxide sheets and mostly in the size of 30 nm. The antibacterial activities of the as-obtained nanocomposite against gram-negative bacteria E. coli and gram-positive bacteria S. aureus were investigated. Moreover, stability of the nanocomposite was measured by silver ion release. It was found that the nanocomposite has enhanced antibacterial activity and outstanding stability, which makes it a potential antibacterial agent.
    Synthesis and Reactivity in Inorganic Metal-Organic and Nano-Metal Chemistry 04/2013; 43(4). DOI:10.1080/15533174.2012.740750 · 0.52 Impact Factor
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    ABSTRACT: Nucleophilic phosphine catalysis has proven to be a practical and powerful synthetic strategy in organic chemistry, which can provide easy access to five-, six-, seven-, and eight-membered nitrogen heterocyclic compounds. The reaction topologies can be controlled by a proper choice of the phosphine catalysts, as well as the functionalization of the reaction substrates. In many cases, the reactions take place smoothly at room temperature, with high efficiency and atom economy. This mini-review presents the recent advances in nucleophilic phosphine catalysis for the synthesis of drug-like nitrogen heterocylic compounds. The nitrogen heterocyclic compounds with significant biological activities derived from the library based on nucleophilic phosphine-catalyzed annulation reactions are also highlighted.
    Mini Reviews in Medicinal Chemistry 04/2013; 13(6). DOI:10.1002/chin.201339238 · 3.19 Impact Factor
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    ABSTRACT: A switchable three-station rotaxane based molecular shuttle with phosphine oxide, dibenzylammonium, and urea functional groups has been developed, where the macrocycle can be easily switched between three different binding sites along the rotaxane thread by addition of acid/base or anions resulting in three stable states. Phosphine oxide is shown to be a potential recognition unit for rotaxane based molecular shuttles and plays an important role as one of three “stations”, allowing the design of a new class of molecular shuttles.
    Chemical Science 03/2013; 4(4):1701-1706. DOI:10.1039/C3SC22048F · 8.60 Impact Factor
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    ABSTRACT: BI-167107 is a new long-acting β2-adrenergic receptor (β2-AR) agonist, and has important application in determining the critical structures of receptor/ligand proteins complex of G-protein-coupled receptor (GPCR). By employing 2-nitroresorcinol as starting material, a practical synthetic route for BI-167107 has been developed, involving 7-step reactions. The structure of the target molecule has been confirmed by 1H NMR, 13C NMR and MS techniques. The advantages of the synthetic route include avoiding use of toxic reagents and being suitable for scale up preparation of BI-167107 and other benzoxazine derivatives.
    Chinese Journal of Organic Chemistry 03/2013; 33(3):634-639. DOI:10.6023/cjoc201211015 · 0.86 Impact Factor
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    ABSTRACT: The title compound, CHO, was obtained formyl-ation of 25,26,27,28-tetra-propoxycalix[4]arene with dichloro-methyl methyl ether and tin tetra-chloride. It adopts a pinched cone conformation, which leads to an open cavity. The two opposite aromatic rings bearing formyl groups are almost parallel, making a dihedral angle of 29.1 (2)°. The other pair of opposite rings are close to being perpendicular, making a dihedral angle of 73.6 (1)°. Adjacent rings are almost perpendicular, making dihedral angles of 78.8 (2), 81.6 (1), 78.2 (1) and 74.7 (1)°.
    Acta Crystallographica Section E Structure Reports Online 03/2013; 69(Pt 3):o424. DOI:10.1107/S1600536813004625 · 0.35 Impact Factor
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    ABSTRACT: The reaction of anilines of type (I) with small amounts of FeCl3·6H2O allows a new and facile access to substituted 1,2-dihydroquinolines.
    ChemInform 02/2013; 44(6). DOI:10.1002/chin.201306100
  • Chinese Journal of Organic Chemistry 01/2013; 33(6):1309. DOI:10.6023/cjoc201302021 · 0.86 Impact Factor
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    ABSTRACT: A straightforward strategy is designed for the fabrication of a magnetically separable P25/CoFe2O4/graphene photocatalyst with differing P25 contents via a facile one step hydrothermal approach. TEM observations show that graphene sheets are exfoliated and decorated with well-dispersed TiO2 and CoFe2O4 nanoparticles. The adsorption capacity and visible-light-driven photocatalytic activity are evaluated in terms of the efficiencies of adsorption and photodegradation of various dyes, including methylene blue (MB), methyl orange (MO) and neutral dark yellow (DY). The evaluation results demonstrate that the P25/CoFe2O4/graphene photocatalyst exhibits the best performance among P25/CoFe2O4/graphene (PCG), CoFe2O4/graphene (CG), P25/CoFe2O4 (PC) and P25/graphene (PG) photocatalysts, not only in the adsorption progress, but also in the photocatalytic degradation. The significant enhancement after combination can be attributed to the synergistic effect among individual components. Furthermore, CoFe2O4 nanoparticles themselves have excellent magnetic properties, which are largely maintained in the composite, and therefore, it is no longer necessary to introduce additional magnetic supports for magnetic separation in a suspension system.
    RSC Advances 01/2013; 3(44):22490. DOI:10.1039/c3ra43416h · 3.71 Impact Factor
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    ABSTRACT: A facile chemical strategy was developed to anchor MnO2 nanoparticles on the surface of graphene sheet. Compared with literature, this approach requires neither extra pretreatment of acid functionalization of graphite nor any post-treatment for the conductivity compensation. Graphene sheet serves as both the nucleation center of the MnO2 nanoparticles and high-efficiency miniature current collectors, endowing an effective rise in electrochemical performance of the overall system. Meanwhile, few layers graphene restrain the aggregation of MnO2 nanoparticles and act as template for the "sandwich structure," which boosts accessible surface areas for the high rates charge and discharge processes. The internal resistance drops of the electrode were small, which is propitious to the high discharge delivery. And the nanocomposite with the unique structure displayed a specific capacitance as high as 340.5 F g(-1). Moreover, the capacitance decrease was only 3.7% after 1000 cycles.
    Journal of Nanoscience and Nanotechnology 01/2013; 13(1):487-92. DOI:10.1166/jnn.2013.6902 · 1.34 Impact Factor
  • Yongsheng Fu, Haiqun Chen, Xiaoqiang Sun, Xin Wang
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    ABSTRACT: A straightforward strategy is designed for the fabrication of a magnetically separable NiFe2O4-graphene photocatalyst with different graphene content. It is very interesting that the combination of NiFe2O4 nanoparticles with graphene sheets results in a dramatic conversion of the inert NiFe2O4 into a highly active catalyst for the degradation of methylene blue (MB) under visible light irradiation. The significant enhancement in photoactivity under visible light irradiation can be ascribed to the reduction of GO, because the photogenerated electrons of NiFe2O4 can transfer easily from the conduction band to the reduced GO, effectively preventing a direct recombination of electrons and holes. The results of the kinetic study indicated that the rate-determining stage is the adsorption process of MB molecules. NiFe2O4 nanoparticles themselves have a strong magnetic property, which can be used for magnetic separation in a suspension system, and, therefore, the introduction of additional magnetic supports is no longer necessary. © 2011 American Institute of Chemical Engineers AIChE J, 2012
    AIChE Journal 11/2012; 58(11). DOI:10.1002/aic.13716 · 2.58 Impact Factor
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    ABSTRACT: Co3O4@graphene nanocomposite (Co3O4@GE) was prepared by a facile hydrothermal route. X-ray diffraction and transmission electron microscope proved Co3O4 nanoparticles with an average size of 5.8 nm were homogeneously dispersed on sonication-exfoliated graphene sheets. X-ray photoelectron spectra indicated a low oxidation degree of graphene in Co3O4@GE. Small amount of functional groups on graphene sheets not only worked as anchor sites for Co3O4 nanoparticles, but also kept the carbon framework with lower defect density. Electrochemical experiments on Co3O4@GE showed high specific capacitance of 415 F/g at a large current density of 3 A/g in 6 M KOH electrolyte, which is valuable for practical application in supercapacitors.
    Materials Letters 09/2012; 82:61–63. DOI:10.1016/j.matlet.2012.05.048 · 2.27 Impact Factor

Publication Stats

317 Citations
98.32 Total Impact Points

Institutions

  • 2010–2015
    • Changzhou University
      Wujin, Jiangsu Sheng, China
  • 2008–2010
    • Jiangsu University
      • School of Chemistry and Chemical Engineering
      Chenkiang, Jiangsu Sheng, China
  • 2003–2009
    • Jiangsu Polytechnic university
      Wujin, Jiangsu Sheng, China
    • Jiangsu Institute of petrochemical Technology
      Wujin, Jiangsu Sheng, China
  • 2000
    • Changzhou Institute of Technology
      Wujin, Jiangsu Sheng, China