Ordered mesoporous C/TiO composites have been fabricated via an evaporation induced co-assembly method, and demonstrated as a highly efficient sonocatalyst. The effects of the carbon content in the composites and calcination temperature have been investigated thoroughly in this work and optimized for the production of well-defined mesoporous C/TiO materials. The resultant composites possess superior "brick-mortar" frameworks with uniform TiO nanocrystals glued by a carbon matrix, and exhibit highly ordered mesostructures with high surface area (∼200 m g). More importantly, the mesoporous C/TiO composites show a high sonocatalytic degradation rate of Rhodamine B. The maximum pseudo-first-order reaction rate constant obtained with the composites 15C-85TiO-450 (C: 15.2 wt%, TiO: 84.8 wt%, calcined at 450 °C) is 0.178 min, which is 2.7 and 4.8 times higher than that of P25 (0.062 min) and ultrasound (0.037 min) alone, respectively. The excellent sonocatalytic performance is a result of fast mass diffusion, enhanced nucleation rate and rapid surface hydroxyl radical oxidation. In addition, the recycling test shows that the sonocatalytic degradation rate with 15C-85TiO-450 is retained even after five cycles, which is related to the well-retained mesostructure with superior mechanical stability. We believe that the present results provide important insights into the design and synthesis of advanced sonocatalysts. This journal is

Qiu Pengpeng    李炜    Kang Kyounglim    Park Beomguk    Luo Wei    赵东元     Khim Jee Hyeong   

Journal of Materials Chemistry A

2014

Highly stabilized mesoporous core-shell-structured CaO-based spheriform CO2 sorbents are fabricated, for the first time, by a novel repeated impregnation coating process combined with the mesoscopic surfactant-templating method. By adopting our established wet-coating strategy along with a sol-gel process, different mesoporous material-shelled sorbents with various shell thicknesses (1-5 μm) and shell compositions (silica/zirconia or pure zirconia) are synthesized. Cyclic CO2 capture performance is tested in a thermogravimetric analyzer with the core-shell pellet sorbents with a ∼1 μm mesoporous zirconia shell exhibiting an unprecedented CO2 uptake capacity of ∼7.2 moles CO2 per kg decarbonated sorbent and the lowest activity loss of only 30.8% after 20 cycles. This is attributed to the unique core-shell coating strategy in which the thermally stable Zr species prevent the aggregation and overgrowth of CaO crystals and sorbent sintering. When comparing the core-shell sorbents with Si-contained mesoporous shells, zirconia shelled ones exhibit significantly more outstanding performance. An attrition study using an air-jet apparatus under the standard test method reveals that the mesoporous zirconia shelled sorbent exhibits enhanced attrition resistance, which is also attributed to the novel core-shell design, offering protection for the reactive core. This journal is

Zhenkun Sun    Mohammad hashem Sedghkerdar    Saayman Jean    Nader Mahinpey    Naoko Ellis    赵东元     Serge Kaliaguine   

Journal of Materials Chemistry A

2014

赵东元    

Journal of Materials Chemistry B

2014

A novel, simple and template-free strategy was developed for the synthesis of uniform magnetic mesoporous TiO nanospindles. Unlike previous synthetic approaches which mainly involve the strict control of sol-gel processes, templates, or capping agents, our strategy is based on an additional post-hydrolysis route, giving rise to mesoporous TiO with a high surface area (366 m g). After crystallization, the mesoporous TiO nanospindles obtained a high surface area (∼117 m g) and a large pore size (∼5.4 nm), and exhibited a high magnetic susceptibility (∼18.0 emu g), as well as showed a remarkable performance for highly selective and rapid enrichment of phosphopeptides with an unprecedented enrichment capacity of ∼300 mg g. These understandings open up a new way for the preparation of functional mesoporous TiO-based materials with high surface areas in a template-free manner, which is of significant importance for applications from both environmental and industrial points of view.

李炜    Liu Minbo    Shanshan Feng    Xiaomin Li    Jinxiu Wang    Dengke Shen    Yuhui Li    Zhenkun Sun    Ahmed Elzatahry    陆豪杰    赵东元    

Materials Horizons

2014

Magnetic yolk-shell structured anatase-based microspheres were fabricated through successive and facile sol-gel coating on magnetite particles, followed by annealing treatments. Upon loading with gold nanoparticles, the obtained functional magnetic microspheres as heterogeneous catalysts showed superior performance in catalyzing the epoxidation of styrene with extraordinary high conversion (89.5%) and selectivity (90.8%) towards styrene oxide. It is believed that the construction process of these fascinating materials features many implications for creating other functional nanocomposites.

Chun Wang    Junchen Chen    Zhou Xinran    Li Wei    刘勇    Yue Qin    Xue Zhaoteng    Yuhui Li    Ahmed Elzatahry    邓勇辉    赵东元    

Nano Research

2014

Core-shell nanoparticles (CSNs) have attracted considerable attention because of their promising applications in a wide range of fields. Recently, substantial efforts have been focused on the development of facile and versatile methods for preparing CSNs with mesoporous SiO or TiO shells because of their fascinating properties, such as high surface area, large pore channels and high pore volume. This Research News reviews the recent progress in facile, versatile and reproducible approaches which are simply extended from the well-known Stöber method to construct mesoporous SiO and TiO shells for uniform multifunctional core-shell nanostructures. Several strategies, including the surfactant-templating process, the long-chain organosilane-assisted approach, the phase transfer assisted surfactant-templating process, and the kinetics-controlled coating approach, are discussed. In addition, new trends in this field for the creation of multifunctional CSNs and novel nanostructures are highlighted. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

李炜    赵东元    

Advanced Materials

2013

One pot successive layer-by-layer (SLBL) strategy is introduced to fabricate the core/shell upconversion nanoparticles (NPs) for the first time by using high boiling-point Re-OA (rare-earth chlorides dissolved in oleic acid at 140 C) and Na-TFA-OA (sodium trifluoroacetate dissolved in oleic acid at room temperature) as shell precursor solutions. This protocol is flexible to deposit uniform multishell on both hexagonal (β) and cubic (α) phase cores by successive introducing of the shell precursor solutions. Shell thickness of the obtained NPs with narrow size distribution (σ < 10%) can be well controlled from 1 monolayer (∼0.36 nm) to more than 20 monolayers (∼8 nm) by simply tuning the amounts of the shell precursors. Furthermore, the tunable doping positions (core doping and shell doping) can also be achieved by adjusting the species and addition sequence of the shell precursors. As a result of the high quality uniform shell and advanced core/shell structures, the optical properties of the obtained core/shell NPs could be improved in upconversion luminescence efficiency (up to 0.51 ± 0.08%), stability (more resistant to quenching by water) and multicolor luminescence emission. © 2012 American Chemical Society.

Xiaomin Li    Dengke Shen    杨建平    Chi Yao    车仁超    张凡    赵东元    

Chemistry of Materials

2013

We report a new solution deposition method to synthesize an unprecedented type of two-dimensional ordered mesoporous carbon nanosheets via a controlled low-concentration monomicelle close-packing assembly approach. These obtained carbon nanosheets possess only one layer of ordered mesopores on the surface of a substrate, typically the inner walls of anodic aluminum oxide pore channels, and can be further converted into mesoporous graphene nanosheets by carbonization. The atomically flat graphene layers with mesopores provide high surface area for lithium ion adsorption and intercalation, while the ordered mesopores perpendicular to the graphene layer enable efficient ion transport as well as volume expansion flexibility, thus representing a unique orthogonal architecture for excellent lithium ion storage capacity and cycling performance. Lithium ion battery anodes made of the mesoporous graphene nanosheets have exhibited an excellent reversible capacity of 1040 mAh/g at 100 mA/g, and they can retain at 833 mAh/g even after numerous cycles at varied current densities. Even at a large current density of 5 A/g, the reversible capacity is retained around 255 mAh/g, larger than for most other porous carbon-based anodes previously reported, suggesting a remarkably promising candidate for energy storage. © 2013 American Chemical Society.

方寅    Yingying Lv    车仁超    Haoyu Wu    Xuehua Zhang    顾栋    郑耿峰    赵东元    

Journal of the American Chemical Society

2013

Highly ordered mesoporous crystalline MoSe is synthesized using mesoporous silica SBA-15 as a hard template via a nanocasting strategy. Selenium powder and phosphomolybdic acid (HPMoO ) are used as Se and Mo sources, respectively. The obtained products have a highly ordered hexagonal mesostructure and a rod-like particle morphology, analogous to the mother template SBA-15. The UV-vis-NIR spectrum of the material shows a strong light absorption throughout the entire visible wavelength region. The direct bandgap is estimated to be 1.37 eV. The high surface area MoSe mesostructure shows remarkable photocatalytic activity for the degradation of rhodamine B, a model organic dye, in aqueous solution under visible light irradiation. In addition, the synthesized mesoporous MoSe possess a reversible lithium storage capacity of 630 mAh g for at least 35 cycles without any notable decrease. The rate performance of mesoporous MoSe is much better than that of analogously synthesized mesoporous MoS, making it a promising anode for the lithium ion battery. Ordered mesoporous crystalline MoSe is synthesized using mesoporous silica as a hard template via a nanocasting strategy. It shows a strong light absorption throughout the entire visible wavelength region and has remarkable photocatalytic activity for the degradation of rhodamine B under visible light irradiation. The synthesized mesoporous MoSe has a reversible lithium storage capacity of 630 mAh g and better rate performance than the analogously synthesized mesoporous MoS. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

施益峰    Hua Chunxiu    Bin Li    Xiangpeng Fang    Yao Chaohua    Yichi Zhang    胡勇胜    Zhaoxiang Wang    陈立泉    赵东元     Galen Stucky   

Advanced Functional Materials

2013

A new photothermal coupling agent for photothermal ablation (PTA) therapy of tumors is developed based on ultrathin PEGylated WO nanowires. After being injected with the nanowire solution, the in vivo tumors exhibit a rapid temperature rise to 50.0 ± 0.5 °C upon irradiation with NIR laser light at a safe, low intensity (0.72 W cm) for 2 min (left-hand mouse in the figure),), resulting in the efficient PTA of cancer cells in vivo in 10 min. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Zhigang Chen    Qian Wang    Huanli Wang    张丽莎    宋国胜    Song Linlin    胡俊青    王宏志    柳建设    朱美芳    赵东元    

Advanced Materials

2013