Crystalline microporous zeolites are one of the most useful catalysts in industrial processes such as oil refining and organic synthesis owing to their strong catalytic performance, high thermal and hydrothermal stabi...
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Crystalline microporous zeolites are one of the most useful catalysts in industrial processes such as oil refining and organic synthesis owing to their strong catalytic performance, high thermal and hydrothermal stabilities, and well-defined micropores with excellent shape-selectivity in catalysis. However, one disadvantage of these zeolitic catalysts is that their pores are too small to be accessed by bulky reactants, thus hindering their use in the fine chemical and petroleum processing industries. To overcome such drawbacks, we have synthesized hierarchically ordered micro-meso-macroporous solid-acid catalysts via a chemically crystallization process in an improved hydrothermal system. Zeolites, including Silicalite-1, ZSM-5, Beta and TS-1, with hierarchically ordered micro-meso-macroporous structure have been synthesized. It is expected that these hierarchical zeolite materials will exhibit superior catalytic performance owing to the improved mass-transfer properties.
Noble‐metal‐free bimetal‐based electrocatalysts have shown high efficiency for water oxidation. Ni and/or Co in these electrocatalysts are essential to provide a conductive, high‐surface area and a chemically stab...
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Noble‐metal‐free bimetal‐based electrocatalysts have shown high efficiency for water oxidation. Ni and/or Co in these electrocatalysts are essential to provide a conductive, high‐surface area and a chemically stable host. However, the necessity of Ni or Co limits the scope of low‐cost electrocatalysts. Herein, we report a hierarchical hollow FeV composite, which is Ni‐ and Co‐free and highly efficient for electrocatalytic water oxidation with low overpotential 390 mV (10 mA cm −2 catalytic current density), low Tafel slope of 36.7 mV dec −1 , and a considerable durability. This work provides a novel and efficient catalyst, and greatly expands the scope of low‐cost Fe‐based electrocatalysts for water splitting without need of Ni or Co.
Unique walnut-shaped porous MnO2/carbon nanospheres (P-MO/C-NSs) with high monodispersity have been designed and prepared for lithium storage via in situ carbonization of amorphous MnO2 nanospheres. Polyvinylpyrrolido...
Unique walnut-shaped porous MnO2/carbon nanospheres (P-MO/C-NSs) with high monodispersity have been designed and prepared for lithium storage via in situ carbonization of amorphous MnO2 nanospheres. Polyvinylpyrrolidone (PVP) is utilized as both the surfactant for morphology control and carbon source for carbon scaffold formation accompanied with MnO2 crystallization. Such a unique walnut-shaped porous nanostructure with an intimate carbon layer provides a large contact area with the electrolyte, short transport path length for Li+, low resistance for charge transfer and superior structural stability. The P-MO/C-NS electrode demonstrates high lithium storage capacity (1176 mA h g−1 at 100 mA g−1), very good cycling stability (100% capacity retention versus the second cycle) and excellent rate capability (540 mA h g−1 at 1000 mA g−1). We propose that it is the deep oxidation of Mn2+ to Mn3+ in P-MO/C-NSs, which results in an extraordinarily high capacity of 1192 mA h g−1 at a current density of 1000 mA g−1 after a long period of cycling, very close to the maximum theoretical reversible capacity of MnO2 (1230 mA h g−1). This is the highest value ever observed for MnO2-based electrodes at such a rate. The high lithium storage capacity and rate capability can be attributed to the enhanced reaction kinetics owing to the walnut-shaped porous nanostructure with an intimate carbon layer. This work provides a meaningful demonstration of designing porous nanostructures of carbon-coated metal oxides undergoing deep conversion reactions for enhanced electrochemical performances
Recent reports demonstrate that a two‐dimensional (2D) structural characteristic can endow perovskites with both remarkable photoelectric conversion efficiency and high stability, but the synthesis of ultrathin 2D pe...
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Recent reports demonstrate that a two‐dimensional (2D) structural characteristic can endow perovskites with both remarkable photoelectric conversion efficiency and high stability, but the synthesis of ultrathin 2D perovskites with large sizes by facile solution methods is still a challenge. Reported herein is the controlled growth of 2D (C 4 H 9 NH 3 ) 2 PbBr 4 perovskites by a chlorobenzene‐dimethylformide‐acetonitrile ternary solvent method. The critical factors, including solvent volume ratio, crystallization temperature, and solvent polarity on the growth dynamics were systematically studied. Under optimum reaction condition, 2D (C 4 H 9 NH 3 ) 2 PbBr 4 perovskites, with the largest lateral dimension of up to 40 μm and smallest thickness down to a few nanometers, were fabricated. Furthermore, various iodine doped 2D (C 4 H 9 NH 3 ) 2 PbBr x I 4− x perovskites were accessed to tune the optical properties rationally.
The W-Cu composites are widely used as weld-ing electrodes,electronic packaging materials,electric discharge materials and heat sinks becauseof the excellent *** this research,theW-40wt.%Cu composites were prepared th...
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The W-Cu composites are widely used as weld-ing electrodes,electronic packaging materials,electric discharge materials and heat sinks becauseof the excellent *** this research,theW-40wt.%Cu composites were prepared through thevacuum hot-press sintering method,and the effectof sintering temperature on the microstructure
Ultra-long,single crystal,Eu-doped α-Si3N4 nanowires were prepared by a simple approach involving nitriding Eu-doped cryomilled nanocrystalline Si powder in NH3 flow at 1350℃ for 4 ***,chemical composition and micro...
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Ultra-long,single crystal,Eu-doped α-Si3N4 nanowires were prepared by a simple approach involving nitriding Eu-doped cryomilled nanocrystalline Si powder in NH3 flow at 1350℃ for 4 ***,chemical composition and microcosmic feature were tested by X-ray diffraction(XRD),field emission scanning electron microscopy(FESEM),transmission electron mi-
Correction for ‘Enhanced upconversion luminescence and modulated paramagnetic performance in NaGdF4:Yb,Er by Mg2+ tridoping’ by Shuwen Zhao et al., RSC Adv., 2016, 6, 81542–81551.
Correction for ‘Enhanced upconversion luminescence and modulated paramagnetic performance in NaGdF4:Yb,Er by Mg2+ tridoping’ by Shuwen Zhao et al., RSC Adv., 2016, 6, 81542–81551.
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