Publications by authors named "Xiong Wen Lou"

Complex molybdenum-based ternary or multinary sulfides hollow structures are developed via a fast precipitation process, together with a subsequent annealing treatment. Benefiting from the merits of high-curvature surfaces with excellent intrinsic catalytic activity, the obtained unique hollow structures exhibit enhanced performance as electrocatalysts for hydrogen production in acidic media.

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Noble metals such as platinum (Pt) are widely used as catalysts in fuel cells and other heterogeneous catalytic processes. However, there is an urgent need to develop substitutes for pure Pt catalysts to reduce the overall use of precious Pt and at the same time to enhance poisoning resistance. A promising strategy is to design Pt based bi- or trimetallic nanostructures because their unique structures and compositions would enhance their catalytic performance.

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Unusual CoS(2) ellipsoids with anisotropic tube-like cavities have been synthesized from the simultaneous thermal decomposition and sulfidation of a preformed cobalt carbonate precursor. The as-prepared CoS(2) ellipsoids show interesting supercapacitive properties with high capacitance and good cycling performance.

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α-Fe(2)O(3) hollow spheres with sheet-like subunits are synthesized by a facile quasiemulsion-templated method. Glycerol is dispersed in water to form oil-in-water quasiemulsion microdroplets, which serve as soft templates for the deposition of the α-Fe(2)O(3) shell. When tested as anode materials for lithium-ion batteries, these α-Fe(2)O(3) hollow spheres manifest greatly enhanced Li storage properties.

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Yolk/shell or 'rattle-typed' nanomaterials with nanoparticle cores inside hollow shells are interesting among the complex hollow nanostructures. Yolk/shell nanoparticles (YSNs) are promising functional nanomaterials for a variety of applications such as catalysis, delivery, lithium-ion batteries and biosensors due to their tailorability and functionality in both the cores and hollow shells. This feature article provides an overview of advances in this exciting area of YSNs, covering systematic synthesis approaches and key promising applications based on the literature and our own recent work.

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Arrays of CuO nanostructures, including nanorods and nanosheets, supported on a Cu substrate have been rationally fabricated from their morphology-controlled Cu(2)(OH)(3)NO(3) precursors by thermal annealing. The as-prepared CuO samples can be directly used as integrated electrodes for lithium-ion batteries without the addition of other ancillary materials such as carbon black or a binder to enhance electrode conductivity and cycling stability. The unique nanostructural features endower them excellent electrochemical performance as demonstrated by high capacities of 450-650 mAh g(-1) at 0.

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A simple approach was proposed to synthesize three types of ellipsoidal hollow nanostructures whose shells are assembled from anatase TiO(2) nanosheets (NSs) with exposed (001) facets. Among them, ellipsoid Fe(3)O(4)@TiO(2)-NS nanorattles can be readily generated as a magnetically separable photocatalyst with enhanced activity through in situ reduction of the α-Fe(2)O(3) core.

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We report an environment-friendly approach to synthesize transition metal oxide nanoparticles (NPs)/reduced graphene oxide (rGO) sheets hybrids by combining the reduction of graphene oxide (GO) with the growth of metal oxide NPs in one step. Either Fe2O3 or CoO NPs were grown onto rGO sheets in ethanol solution through a solvothermal process, during which GOs were reduced to rGO without the addition of any strong reducing agent, e.g.

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We report an interesting approach for efficient synthesis of SnO(2) hollow spheres inside mesoporous silica "nanoreactors". The as-prepared products are shown to have a uniform size distribution and good structural stability. When evaluated for their lithium storage properties, these SnO(2) hollow spheres manifest improved capacity retention.

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Facile hydrothermal methods have been developed to synthesize large Co3O4 nanocubes, β-Co(OH)2 hexagonal nanodiscs and nanoflowers. Samples are thoroughly characterized by field-emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Brunauer-Emmett-Teller method, and thermogravimetric analysis. The Co3O4 nanocubes have an average size of about 350 nm with a perfect cubic shape, and the β-Co(OH)2 nanodiscs are uniform hexagonal platelets, whereas the β-Co(OH)2 nanoflowers are assembled from large sheetlike subunits.

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Despite the significant advancement in making hollow structures, one unsolved challenge in the field is how to engineer hollow structures with specific shapes, tunable compositions, and desirable interior structures. In particular, top-down engineering the interiors inside preformed hollow structures is still a daunting task. In this work, we demonstrate a facile approach for the preparation of a variety of uniform hollow structures, including Cu(2)O@Fe(OH)(x) nanorattles and Fe(OH)(x) cages with various shapes and dimensions by template-engaged redox etching of shape-controlled Cu(2)O crystals.

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TiO(2) and SnO(2)@TiO(2) hollow spheres assembled from anatase TiO(2) nanosheets with exposed (001) high-energy facets are constructed via a templating approach, and the as-prepared samples exhibit enhanced lithium storage properties.

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In this work, we report a facile top-down approach to fabricate uniform single-crystal α-Fe(2)O(3) nanodiscs via selective oxalic acid etching. Phosphate ions are employed as a capping agent to control the etching to along the [001] direction. We also show that α-Fe(2)O(3) melon-like microparticles with contrasting textural properties can be generated using the same approach.

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Uniform carbon-coated MoO(2) nanospheres assembled from small primary nanocrystals have been synthesized by a one-pot hydrothermal method followed by thermal annealing. Because of the desirable structural features, these core-shell MoO(2)@carbon nanospheres exhibit significantly improved electrochemical performance for high-rate reversible lithium storage.

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Anatase TiO(2) having different percentages of (001)/(101) surface demonstrated different behaviors for Li(+) ions insertion and much enhanced rate performance of Li-ion batteries.

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Article Synopsis
  • Researchers created uniform hollow nanospheres of SnO(2) using a simple modified method, allowing control over the interior void space by adjusting reaction time.
  • The process, based on the inside-out Ostwald ripening mechanism, can also be used to make rattle-type hollow structures, exemplified by alpha-Fe(2)O(3)@SnO(2).
  • When tested for lithium storage, the rattle-type structures showed lower initial irreversible loss and higher capacity than the hollow spheres, highlighting the benefits of combining different materials for better performance.
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Synthesis of nanocrystals with exposed high-energy facets is a well-known challenge in many fields of science and technology. The higher reactivity of these facets simultaneously makes them desirable catalysts for sluggish chemical reactions and leads to their small populations in an equilibrated crystal. Using anatase TiO(2) as an example, we demonstrate a facile approach for creating high-surface-area stable nanosheets comprising nearly 100% exposed (001) facets.

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Bending properties of short (15-90 bp), double-stranded DNA fragments are quantified using fluorescence resonance energy transfer and small angle x-ray scattering. Results from both types of measurements indicate that short double-stranded DNA fragments exhibit surprisingly high flexibility. These observations are discussed in terms of base-pair-level length fluctuations originating from dynamic features of Watson-Crick base pairs.

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