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  • Uniform core-shell structured magnetic mesoporous TiO nanospheres as a highly efficient and stable sonocatalyst for the degradation of bisphenol-A

    • 摘要:

      Uniform core-shell structured magnetic mesoporous TiO (FeO@SiO@mTiO) nanospheres were fabricated via a kinetically controlled Stöber method. A silica interlayer with a thickness of ∼25 nm was introduced as a passivation barrier to prevent photodissociation, as well as increase the thermal stability of the core-shell materials. After crystallizing at 600 °C under nitrogen, the resultant nanospheres (FeO@SiO@mTiO-600) possessed well-defined core-shell structures with a high magnetic susceptibility (∼17.0 emu g) and exhibited uniform mesopores (∼5.2 nm), large BET surface area (∼216 m g) and large pore volume (∼0.20 cm g). More importantly, the magnetic mesoporous TiO was demonstrated for the first time as a highly efficient and stable sonocatalyst for the degradation of bisphenol-A. The pseudo first-order-reaction constant of the magnetic mesoporous TiO was measured to be 0.164 min, which is 1.49 and 2.27 times higher than that of P25 and ultrasound alone, respectively. The remarkable performance is attributed to the fast mass diffusion, large adsorption rate and enhanced hydroxyl-radical-production rate of the nanospheres. More importantly, the catalyst can be easily recycled within 2 minutes using an external magnetic field, and a constant catalytic activity is retained even after eight cycles. This study paves a promising way for the design and synthesis of magnetically separable sonocatalysts for the degradation of organic pollutants, which is of significant importance for practical applications from both environmental and industrial points of view. This journal is

    • 作者:

      Qiu Pengpeng    李炜    Thokchom Binota    Park Beomguk    Cui Mingcan    赵东元     Khim Jee Hyeong   

    • 刊名:

      Journal of Materials Chemistry A

    • 在线出版时间:

      2015

  • Lab on upconversion nanoparticles: Optical properties and applications engineering via designed nanostructure

    • 摘要:

      Over the past decade, high-quality lanthanide doped upconverting nanoparticles (UCNPs) have been successfully synthesized with the rapid development of nanotechnology. Due to the unique electron configuration of lanthanide ions, there are rich energy level structures in the near-infrared, visible and ultraviolet spectral range. However, for UCNPs, only a limited number of efficient upconversion excitation and emission have been generated due to the limited number of sensitizer (Yb) and activator (Tm, Er, and Ho) ions, and the application is mainly focused on the bio-imaging by using the upconversion luminescence of UCNPs. Recently, more and more researchers have started to focus on tuning of upconversion optical properties and developing of multi-functional UCNPs by using the combination of sub-lattice mediated energy migration, core@shell structural engineering and UCNPs based nanocomposites which greatly expands the range of applications for lanthanide-doped UCNPs. Therefore, a "nanolab" can be created on UCNPs, where the property modulation can be realized via the designed host-dopants combinations, core@shell nanostructure, energy exchange with "alien species" (organic dyes, quantum dots, etc.), and so on. In this paper, we provide a comprehensive survey of the latest advances made in developing lanthanide-doped UCNPs, which include excitation and emission energy levels guided designing of the UCNP nanostructure, the synthesis techniques to fabricate the nanostructure with optimum energy level structure and optical properties, the fabrication of UCNPs-based nanocomposites to extend the applications by introducing the additional functional components, or integrating the functional moiety into one nanocomposite. This journal is

    • 作者:

      Xiaomin Li    张凡    赵东元    

    • 刊名:

      Chemical Society Reviews

    • 在线出版时间:

      2015

  • Preparation of a mesoporous Cu-Mn/TiO2 composite for the degradation of Acid Red 1

    • 摘要:

      Heterogeneous catalysts which show high catalytic performance, structural stability, and low toxicity, are greatly required to efficiently degenerate organic pollutants in waste water in advanced oxidation processes (AOPs). In this paper, a mesoporous Cu-Mn/TiO2 composite heterogeneous catalyst was successfully prepared, which has a stable crystalline TiO2 mesostructure as the support, and well-dispersed Cu-Mn oxides as the catalytic active sties. Its Cu, Mn content is measured to be 5.7 and 6.0 wt%, and the BET surface area is measured to be 97 m2 g-1 with a pore size of ∼6.0 nm and pore volume of 0.15 cm3 g-1. Using the prepared Cu-Mn/TiO2 composite as an AOPs catalyst for the degeneration of Acid Red 1, it can efficiently (>99%) degenerate the model pollutant in water within only 90 min. Compared with homogeneous catalysts, it can retain its catalytic performance over a wide pH range (3-9) and can be recycled for at least five times while still possessing the decolorization efficiency of 89%. By analyzing the catalytic process, a possible catalytic procedure for the degradation of Acid Red 1 has been proposed. Furthermore, using bulk Cu-Mn oxides, Cu-Mn/P25, and Cu-Mn/SBA-15 as reference catalysts, we propose that the excellent catalytic performance of Cu-Mn/TiO2 could be ascribed to the anatase mesoporous TiO2, which not only offers a stable matrix with high surface area for Cu-Mn catalysts, but also serves as a type of catalytic promoter for the synergistic catalytic degeneration of Acid Red 1.

    • 作者:

      Hongyang Min    Xianqiang Ran    范建伟    Sun Yu    杨建平    Wei Teng    张伟贤    李光明    赵东元    

    • 刊名:

      Journal of Materials Chemistry A

    • 在线出版时间:

      2015

  • Selectivity Enhancement in Dynamic Kinetic Resolution of Secondary Alcohols through Adjusting the Micro-Environment of Metal Complex Confined in Nanochannels: A Promising Strategy for Tandem Reactions

    • 摘要:

      (Figure Presented). Dichloro(η6-p-cymene) (1-butyl-3-cyclohexyl-imidazolin-2-ylidene) ruthenium(II) (RuL) was synthesized and confirmed. Five heterogeneous catalysts with similar ruthenium cores were prepared by chemical immobilization method using various silica-based supports, including mesoporous silica SBA-15 of different pore sizes (Ru/Si-9, Ru/Si-8, and Ru/Si-7), nonporous silica particles (Ru/SiO2), and surface trimethylsilylated SBA-15 (Ru/SiMe). The dynamic kinetic resolution (DKR) of 1-phenylethanol, which includes metal-enzyme bicatalytic racemization in tandem with stereoselective acylation, gave product in 99% yield and 0% ee with homogeneous catalyst RuL, whereas the heterogeneous Ru/Si-8 exhibited high catalytic activity and enantioselectivity (up to 96% yield and 99% ee). The racemization and acylation abilities of different catalysts were analyzed. The influences of pore size and surface properties for heterogeneous catalysts were investigated, and the nanocage effect was found to be the key factor in stereoselectivity. The catalyst Ru/Si-8 performed well in reactions with various substrates and can be reused for at least seven times.

    • 作者:

      Cao Hui    Zhu Xiao-Han    Wang Dong    Zhenkun Sun    邓勇辉    侯秀峰    赵东元    

    • 刊名:

      ACS Catalysis

    • 在线出版时间:

      2015

  • Controllable Synthesis of Mesoporous Peapod-like Co3O4@Carbon Nanotube Arrays for High-Performance Lithium-Ion Batteries

    • 摘要:

      Transition metal oxides are regarded as promising anode materials for lithium-ion batteries because of their high theoretical capacities compared with commercial graphite. Unfortunately, the implementation of such novel anodes is hampered by their large volume changes during the Li+ insertion and extraction process and their low electric conductivities. Herein, we report a specifically designed anode architecture to overcome such problems, that is, mesoporous peapod-like Co3O4@carbon nanotube arrays, which are constructed through a controllable nanocasting process. Co3O4 nanoparticles are confined exclusively in the intratubular pores of the nanotube arrays. The pores between the nanotubes are open, and thus render the Co3O4 nanoparticles accessible for effective electrolyte diffusion. Moreover, the carbon nanotubes act as a conductive network. As a result, the peapod-like Co3O4@carbon nanotube electrode shows a high specific capacity, excellent rate capacity, and very good cycling performance.

    • 作者:

      顾栋    李炜    Fei Wang    Bongard Hans    Spliethoff Bernd    Schmidt Wolfgang    Weidenthaler Claudia    夏永姚    赵东元     Ferdi Schüth   

    • 刊名:

      Angewandte Chemie - International Edition

    • 在线出版时间:

      2015

  • Review on the progress of core-shell structured zeolite molecular sieve materials

    • 摘要:

      The unique zeolite-based core-shell structures showed excellent performance in the coal chemical, petrochemical and fine chemical industries. The synthesis and applications of core-shell structured zeolite composite materials were systematically reviewed. Three core-shell structures for the zeolite composite materials were involved, including zeolite-based crystal as cores, zeolite-based materials as the shells and zeolites@zeolites core-shell structures. The hollow zeolite crystals and the magnetic@zeolites core-shell composites were also mentioned as two kinds of distinguished core-shell structured zeolite composites. The development and application prospects of zeolite-based core-shell structure composite materials were also discussed.

    • 作者:

      Xue Zhaoteng    Tang Xueting    Wang Wenxing    赵东元    

    • 刊名:

      Shiyou Xuebao, Shiyou Jiagong/Acta Petrolei Sinica (Petroleum Processing Section)

    • 在线出版时间:

      2015

  • Controllable Synthesis of Mesoporous Peapod-like Co3O4@Carbon Nanotube Arrays for High-Performance Lithium-Ion Batteries

    • 摘要:

      Abstract Transition metal oxides are regarded as promising anode materials for lithium-ion batteries because of their high theoretical capacities compared with commercial graphite. Unfortunately, the implementation of such novel anodes is hampered by their large volume changes during the Li+ insertion and extraction process and their low electric conductivities. Herein, we report a specifically designed anode architecture to overcome such problems, that is, mesoporous peapod-like Co3O4@carbon nanotube arrays, which are constructed through a controllable nanocasting process. Co3O4 nanoparticles are confined exclusively in the intratubular pores of the nanotube arrays. The pores between the nanotubes are open, and thus render the Co3O4 nanoparticles accessible for effective electrolyte diffusion. Moreover, the carbon nanotubes act as a conductive network. As a result, the peapod-like Co3O4@carbon nanotube electrode shows a high specific capacity, excellent rate capacity, and very good cycling performance.

    • 作者:

      顾栋    李炜    Fei Wang    Bongard Hans    Spliethoff Bernd    Schmidt Wolfgang    Weidenthaler Claudia    夏永姚    赵东元     Ferdi Schüth   

    • 刊名:

      Angewandte Chemie - International Edition

    • 在线出版时间:

      2015

  • Erratum: Single-band upconversion nanoprobes for multiplexed simultaneous in situ molecular mapping of cancer biomarkers (Nature Communications (2015) 6 (6938))

    • 摘要:

    • 作者:

      周磊    Rui Wang    Chi Yao    Xiaomin Li    Wang Chengli    张晓燕    Xu Congjian    Zeng Aijun    赵东元     张凡   

    • 刊名:

      Nature Communications

    • 在线出版时间:

      2015

  • Incorporation of Al3+ ions to promote the stabilization effect of (NH4)2SiF6 treatment on the hydrothermal stability of mesoporous SBA-15 zeolite

    • 摘要:

      This work demonstrates an improved (NH4)2SiF6 treatment to enhance the hydrothermal stability of mesoporous SBA-15 zeolite. In this treatment, Al3+ ions are incorporated into SBA-15 zeolite first, then it is treated with 5% (NH4)2SiF6 solution according to 1% SiO2 of SBA-15 and finally washed with HCl (2 mol/L) to remove the pre-incorporated Al3+ ions. The obtained SBA-15 exhibits higher hydrothermal stability than that without pre-incorporated Al3+. Compared with the latter, the sample maintains a better ordered mesostructure and a larger surface area (271 m2/g) after hydrothermal treatment at 800℃ for 12 h in 100% steam. The results show that incorporating Al3+ ions into SBA-15 zeolite before (NH4)2SiF6 treatment obviously promotes the stabilization effect of (NH4)2SiF6 treatment. The mechanism suggests that the incorporated Al3+ ions can effectively capture F- ions that have been released from (NH4)2SiF6, and thus reduce their etching into the SBA-15 zeolite framework. This ensures that the positive factors of (NH4)2SiF6 treatment, such as silicon insertion and surface hydrophobization by F- ions, play effective roles in the improvement of the hydrothermal stability of SBA-15 zeolite. This promoting effect of the Al3+ ions is closely related to the method that is used to introduce the Al3+ and the SBA-15 zeolite processing temperature.

    • 作者:

      Zou Chenglong    Sha Guanyu    黄曜    牛国兴    赵东元    

    • 刊名:

      Cuihua Xuebao/Chinese Journal of Catalysis

    • 在线出版时间:

      2015

  • A Facile Multi-interface Transformation Approach to Monodisperse Multiple-Shelled Periodic Mesoporous Organosilica Hollow Spheres

    • 摘要:

      The synthesis of well-defined and complex hollow structures via a simple method is still a major challenge. In this work, a facile and controllable "multi-interface transformation" approach for preparation of monodisperse multi-shelled periodic mesoporous organosilica (PMO) hollow spheres has been established by a one-step hydrothermal treatment of successively grown organosilica particles. The multi-shelled PMO hollow spheres have inorganic-organic hybrid frameworks, controllable number (1-4) of shells, high surface area (∼805 m2/g), accessible ordered mesochannels (∼3.2 nm), large pore volume (1.0 cm3/g), and uniform and tunable diameter (300-550 nm), chamber size (4-54 nm), and shell thickness (10-30 nm). In addition, various organic groups (alkyl, aromatic, and heteroelement fragments) are successfully incorporated into the multi-shelled PMO hollow spheres by successively adding different bridged organosilica precursors. Notably, the distribution of different kinds of organic groups in the multi-shelled PMO hollow spheres can be precisely controlled, showing great potential for future applications. We propose that the formation of the multi-shelled PMO hollow structures is ascribed to the creation of multiple highly cross-linked organosilica interfaces, providing a new and interesting fundamental principle for PMO materials. Due to their unique structure and frameworks, triple-shelled ethane-bridged PMO hollow spheres were successfully loaded with an anti-cancer drug doxorubicin and perfluoropentane gas, which present excellent effects in the killing of cancer cells and ultrasound imaging. It is expected that the multi-interface transformation strategy provides a simple, controllable, versatile, and template-free method for preparation of various multifunctional PMOs for different applications. (Figure Presented).

    • 作者:

      Zhaogang Teng    Xiaodan Su    Yuanyi Zheng    Zhang Junjie    Ying Liu    王守巨    Wu Jiang    陈国韬    Wang Jiandong    赵东元     Guangming Lu   

    • 刊名:

      Journal of the American Chemical Society

    • 在线出版时间:

      2015

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