Last Updated on April. 10, 2017

最新研究进展 | Recent Highlights

Jan 30, 2017

4 Water-evaporation-induced electricity with nanostructured carbon materials

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Water evaporation is a ubiquitous natural process that harvests thermal energy from the ambient environment. It has previously been utilized in a number of applications including the synthesis of nanostructures and the creation of energyharvesting devices. Here, we show that water evaporation from the surface of a variety of nanostructured carbon materials can be used to generate electricity. We find that evaporation from centimetre-sized carbon black sheets can reliably generate sustained voltages of up to 1 V under ambient conditions. The interaction between the water molecules and the carbon layers and moreover evaporation-induced water flow within the porous carbon sheets are thought to be key to the voltage generation. This approach to electricity generation is related to the traditional streaming potential, which relies on driving ionic solutions through narrow gaps, and the recently reported method of moving ionic solutions across graphene surfaces, but as it exploits the natural process of evaporation and uses cheap carbon black it could offer advantages in the development of practical devices.Read more

Nov 25, 2016

Hydroelectric generator from transparent flexible zinc oxide nanofilms

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Harvesting wave energy based on waving potential, a newly found electrokinetic effect, is attractive but limited mainly to monolayer graphene. Here we demonstrate that moving a transparent flexible ZnO nanofilm across the surface of ionic solutions can generate electricity. The generated electricity increases linearly with the moving velocity with an open-circuit voltage up to tens of millivolt and a short-circuit current at the order of microampere. The harvested electricity can be efficiently scaled up through series and parallel connections. Theoretical simulations show that it is the proper electrical property that endows the ZnO nanofilm with the outstanding capacity in harvesting the wave energy.Read more

Apr 13, 2016

Boron Nitride Nanostructures: Fabrication, Functionalization and Applications

Boron nitride (BN) structures are featured by their excellent thermal and chemical stability and unique electronic and optical properties. However, the lack of controlled synthesis of quality samples and the electrically insulating property largely prevents realizing the full potential of BN nanostructures. This review provides a comprehensive overview of the current status of the synthesis of two dimensional hexagonal BN sheets, three dimensional porous hexagonal BN materials and BN-related heterostructures, highlighting the advantages of different synthetic methods. In addition, structural characterization, functionalizations and prospective applications of hexagonal BN sheets are intensively discussed. One-dimensional BN nanoribbons and nanotubes are then discussed in terms of structure, fabrication and functionality. In particular, the existing arts in pursuit of tunable electronic and magnetic properties in various BN structures are surveyed, calling upon synergetic experimental and theoretical efforts to address the challenges for pioneering the applications of BN into functional devices. Finally, the progress on BN superstructures and novel B nanostructures is briefly introduced.Read more

Mar 15, 2016

Tunable electronic and magneticproperties of two-dimensionalmaterials and theirone-dimensional derivatives

Low-dimensional materials exhibit many exceptional properties and functional-ities which can be efficiently tuned by externally applied force or fields. Here wereview the current status of research on tuning the electronic and magnetic prop-erties of low-dimensional carbon, boron nitride, metal-dichalcogenides, phos-phorene nanomaterials by applied engineering strain, external electric field andinteraction with substrates, etc, with particular focus on the progress of computa-tional methods and studies. We highlight the similarities and differences of theproperty modulation among one- and two-dimensional nanomaterials. Recent breakthroughs in experimental demonstration of the tunable functionalities intypical nanostructures are also presented. Finally, prospective and challenges forapplying the tunable properties into functional devices are discussed.Read more

Aug 25, 2015

Large-Area, Periodic, Hexagonal Wrinkles on Nanocrystalline Graphitic Film

Sinusoidal wrinkles develop in compressively stressed film as a means to release stored elastic energy. Here, a simple way to fabricate large-area, periodic, hexagonal wrinkled pattern on nanocrystalline graphitic films grown on c-plane sapphire (<50 nm thick) by the spontaneous delamination–buckling of the as-grown film during cooling is reported. According to the continuum mechanics calculation, strain-relief pattern adopting the hexagonal wrinkled pattern has a lower elastic energy than that of the telephone cord wrinkle at thickness regime below 50 nm. A high-fidelity transfer method is developed to transfer the hexagonal wrinkled films onto arbitrary substrates. Nanoindentation studies show that hexagonal wrinkle film engineered this way may act as shock absorber. The hexagonal wrinkled carbon film is able to selectively promote the differentiation of human mesenchymal stem cell toward the osteogenic lineage in the absence of osteogenic inducing medium.Read more

Jun 15, 2015

Large Single-Crystal Hexagonal Boron Nitride Monolayer Domains with Controlled Morphology and Straight Merging Boundaries

Hexagonal boron nitride monolayers with domain sizes up to 700 μm2 and geometry from triangle to hexagon are fabricated through a refined control over the precursor and morphology of the copper substrate. Hydrogen etching is shown to tailor the h-BN monolayers precisely along the grain boundaries, providing their morphology over micro­meter scale and a new avenue toward fabricating nanoribbons.Read more

Jun 14, 2015

Low-voltage Driven Graphene Foam Thermoacoustic Speaker

A low-voltage-driven thermoacoustic speaker is fabricated using graphene foams synthesized by a chemical vapor deposition method. When an audio signal is applied to the speaker, sound waves are produced due to the periodicity of air vibrations induced by Joule heating. Read more

Jun 4, 2014

2D materials: Metallic when narrow

2D materials Metallic when narrow
Subnanometre metallic wires can be engineered from semiconducting sheets of transition-metal dichalcogenides by means of a focused electron beam.Read more

May 21, 2014

Bending Poisson Effect in Two-Dimensional Crystals

Bending Poisson Effect in Two-Dimensional Crystals
significant exotic lateral strains can be induced by pure bending in two-dimensional crystals, in which the lateral components of chemical bonds can respond to bending curvature directly.Read more

May 6, 2014

Waving potential in graphene

Waving potential in graphene
Moving a liquid–gas boundary along a piece of graphene can induce a waving potential of up to 0.1 V. This waving potential arises from charge transfer in graphene driven by a moving boundary of an electric double layer between graphene and ionic solutions.Read more