Hollow Octahedra Research Articles

Chemical reaction controlled synthesis of Cu2O hollow octahedra and core–shell structures

Download options Please wait... Supplementary files Supplementary information PDF (349K) Article information DOI https://doi.org/10.1039/C3CE41745J Article type Paper Submitted 30 Aug 2013 Accepted 05 Oct 2013 First published 09 Oct 2013 Download Citation CrystEngComm, 2013,15, 10028-10033 BibTex EndNote MEDLINE ProCite ReferenceManager RefWorks RIS Permissions Request permissions Chemical reaction controlled synthesis of Cu2O hollow octahedra and core–shell structures K. Chen, S. Song and D. Xue, CrystEngComm, 2013, 15, 10028 DOI: 10.1039/C3CE41745J To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page. If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given. If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page. Read more about how to correctly acknowledge RSC content. Social activity Tweet Share Search articles by author Kunfeng Chen Shuyan Song Dongfeng Xue

Template-assisted synthesis of single-crystalline Mn3O4 nanoframes and hollow octahedra

Single-crystalline Mn3O4 nanoframes and hollow octahedra were firstly prepared via a polyethylene glycol template-assisted route under hydrothermal conditions. The synthesized Mn3O4 nanoframes showed both square-shaped hollow interiors and the outward solid rims while their relative octahedra displayed hollow cores of about 75 nm. In addition, the formation mechanisms of Mn3O4 hollow nanostructures and the key roles of polyethylene glycol templates were discussed.

Transformation from hollow carbon octahedra to compressed octahedra and their use in lithium-ion batteries

Hollow carbon octahedra with an average size of 300nm and a shell thickness of 2.5nm were prepared by a reaction starting from ferrocene and Mg(CH3COO)2·4H2O at 700°C for 10h. They became compressed and turned into deflated balloon-like octahedra when the reaction time was increased to 16h. It was proposed that the gas pressure generated during the reaction process induced the transformation from broken carbon hollow octahedra into deflated balloon-like compressed octahedra. X-ray powder diffraction and Raman spectroscopy indicate that the as-obtained carbon products possess a graphitic structure and high-resolution transmission electron microscopy images indicate that they have low crystallinity. Their application as an electrode shows reversible capacity of 353mAhg−1 after 100 cycles in the charge/discharge experiments of secondary lithium ion batteries.

Facile synthesis of lithium niobate from novel precursor H2(H2O)NB2O6

Lithium niobate hollow spheres and octahedra with rough surfaces have been successfully fabricated from a novel H2(H2O)Nb2O6 precursor by in situ combustion treatment. X-ray diffraction and scanning electronic microscopy were used to study the phase composition and microstructure of the obtained lithium niobate. Experimental results demonstrated that H2(H2O)Nb2O6 hollow spheres and octahedra can be facilely transformed into their corresponding hexagonal phase LiNbO3 crystallites without destroying the microstructures, even though through an intense combustion treatment. These hollow and rough octahedral structures may open up large perspectives for LiNbO3. The present in situ conversion strategy by coating flexible H2(H2O)Nb2O6 precursors to form microscopic reactors could also be extended to other niobates with various structures.

Shape-controlled synthesis and characterization of cobalt oxides hollow spheres and octahedra

We demonstrated that single-crystalline cobalt monoxide (CoO) hollow spheres and octahedra could be selectively synthesized via thermal decomposition of cobalt(II) acetylacetonate in 1-octadecene solvent in the presence of oleic acid and oleylamine. The morphologies and sizes of as-prepared CoO nanocrystals could be controlled by adjusting the reaction parameters. Cobalt oxide (Co(3)O(4)) hollow spheres and octahedra could also be selectively obtained via calcination method using corresponding CoO hollow spheres and octahedra as precursors. The morphology, size and structure of the final products were investigated in detail by XRD, SEM, TEM, HRTEM, DSC, TG, and XPS. The results revealed that the electrochemical performance of cobalt oxide hollow spheres is much better than that of cobalt oxide octahedra, which may be related to the degree of crystallinity, size, and morphology of cobalt oxides.

Morphology Evolution of Cu2O from Octahedra to Hollow Structures

Octahedral Cu2O crystals with all edge length about I pill were synthesized by reducing it copper-citrate complex With glucose. The morphology and Structure Of Cu2O particles were greatly affected by the concentration of glucose, reaction temperature, and time. When the concert tralion of glucose increased from 0.6 to 1.6 M, the morphology of Cu2O Could be changed from octahedral single crystals to spherical polycrystals. When the reaction time was prolonged from 6 to 36 11, solid Cu2O Octahedra could be changed to it mixture of hollow Cu2O octahedra and irregular Cu particles. After removing Cu particles. pure Cu2O hollow Octahedra could be obtained. The formation mechanism Of hollow Cu2O octahedra was discussed. Similarly, hollow Cu2O spheres could also be obtained using this method. The prepared hollow Octahedra[ Cu2O Particles exhibited higher pholoocatalytic activity for photodegradation of p-nitrophenol aqueous Solution under visible-light illumination thim other Cu2O particles with different morphologies (hollow spheres, solid octahedra, and solid spheres).

A redox-hydrothermal route to β-MnO 2 hollow octahedra

Beta-Manganese dioxides' (β-MnO 2) hollow octahedra have been prepared by a synergetic redox reaction using cuprous chloride (CuCl) and hydrochloric acid (HCl) as reductants and potassium permanganate (KMnO 4) as oxidant through a hydrothermal route. During the process, the self-generated chlorine (Cl 2) gas bubbles and HCl's etching appear to be necessary for the formation of MnO 2 hollow structure. The catalytic efficiency of the prepared β-MnO 2 hollow octahedra was high which has been demonstrated by the catalytic oxidation of methylene blue (MB) dye in the presence of hydrogen peroxide (H 2O 2) under natural light.

Synthesis of Single-Crystalline Hollow Octahedral NiO

We have successfully fabricated single-crystalline hollow NiO crystals with well-defined octahedral morphology. With detailed investigations by using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and thermogravimetric analysis, we propose a growth mechanism of the hollow octahedra. It is the first report that hollow octahedral materials can be synthesized via a template-assisted carbothermal method. During the process, carbon templates appear to be necessary for the formation of single-crystalline hollow NiO octahedra. The proposed facile strategy can be extended to synthesize other polyhedral materials such as metal oxides (Co3O4, etc.).

Low-cost synthesis of hollow Cu 2O octahedra with more than one shell

Inorganic materials with hollow and multilayer structures have attracted many interests because of their special applications. In this paper we reported a low-cost synthetic route for hollow cuprous oxide octahedra with more than one shell. Various characterizations identified the as-obtained powder as pure, uniform, and monodispersed Cu 2O octahedra wrapped by the {111} faces. To determine the formation mechanism, the time-dependent experiments were conducted and the results showed that the intermediate phase, CuO, precipitated out first and its reduction by amino acids led to the formation of hollow Cu 2O structures.

A 1.7-kilobase single-stranded DNA that folds into a nanoscale octahedron.

Molecular self-assembly offers a means of spontaneously forming complex and well-defined structures from simple components. The specific bonding between DNA base pairs has been used in this way to create DNA-based nanostructures and to direct the assembly of material on the subnanometre to micrometre scale. In principle, large-scale clonal production of suitable DNA sequences and the directed evolution of sequence lineages towards optimized behaviour can be realized through exponential DNA amplification by polymerases. But known examples of three-dimensional geometric DNA objects are not amenable to cloning because they contain topologies that prevent copying by polymerases. Here we report the design and synthesis of a 1,669-nucleotide, single-stranded DNA molecule that is readily amplified by polymerases and that, in the presence of five 40-mer synthetic oligodeoxynucleotides, folds into an octahedron structure by a simple denaturation-renaturation procedure. We use cryo-electron microscopy to show that the DNA strands fold successfully, with 12 struts or edges joined at six four-way junctions to form hollow octahedra approximately 22 nanometres in diameter. Because the base-pair sequence of individual struts is not repeated in a given octahedron, each strut is uniquely addressable by the appropriate sequence-specific DNA binder.