Research Interest

    Carbon Nanomaterials 

& Nanostructures

 

 

  • Carbon nanotube

 

  • Graphene

 

  • 2D atomic layers

 

  • Nanodiamond

 

  • Synchrotron radiation
    for Nanomaterials

 

 

 

 

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As a rich material, carbon (C) exists as three predominant allotropes: diamond,  graphite and amorphous  carbon. There are distinguished by their crystallize structure and the hybridization of the carbon atoms therein. Carbon is also an extremely versatile molecule: it can form linear or zigzag chains, rings (Benzene and other aromatic compounds), buckyballs (spherical molecules), sheets (graphite and bucktubes), or blocks (diamond). Nanocarbon, including 0D fullerenes, 1D carbon nanotube, 2D graphene and 3D diamond, have attracted  great attention  in the scientific community. 

 

Carbon nanotube

 

 

With the past decades extensive research has shed light into the  structure, reactivity and properties  of  carbon  nanotube (CNT) since its discovery.  This new carbon allotrope is theoretically constructed by rolling up a  graphene sheet into a cylinder with the hexagonal rings joining seamlessly. Depending on the roll-up vector,  CNTs exhibit different physical and electronic properties, e.g. they either possess metallic or semiconducting  character. Apart from their outstanding electronic properties providing the foundation for multiple applications as nanowires, field-effect transistors and electronic devices, carbon nanotues surmount any  other  substance class in their mechanical properties, making CNT an ideal candidate for reinforcing fibers and  polymers. However, in order to tap the full potential of CNT in electronics, photonics, as  sensor  or in composite materials, two major obstacles have to be overcome, e.g. controllable growth with  designed  structures/properties on the one hand and post-separation according diameter and/or chirality on the  other  hand. Up to now, the as-produced material contains nanotubes of differing lengths,diameters and chiralities, therefore including semiconducting and metallic nanotubes.    

                                                                                                                            This inhomogeneity still forms the bottleneck for nanotube-based  technological process. Based on  these  challenges, our research are focusing on the selective growth with the diameter and chirality control, the post functionalization and separation, the specific applications in the fields of biomedicine, nanocomposite,  energy  generation and storage, and etc.

 

Graphene

 

 

Graphite has a layered structure, where the sp2 hybridized carbon atoms are arranged in a hexagonal lattice  in each place. Recent studies have demonstrated that monolayer graphite (so-called graphene), a one atom-thick planar sheet of sp2 bonded carbon atoms densely packed in a honeycomb crystal lattice, can exist  as  a  stable material, and it has distinct properties that are not observed in 0D, 1D, or 3D forms of carbon. In 2004,  Geim and co-workers were successful in isolating single-layer graphite on an insulating substrate by using a

micromechanical cleavage method, which was rewarded with the Nobel Prize in Physics in 2010.  After the  experimental isolation was realized, scientists have revealed a rich variety of physical phenomenon in  this 2D

atomic carbon monolayer. However, the field of graphene research is still very much in its early. Our research 

are focusing on graphene synthesis and engineering with  specific applications in energy, biomedicine and nanocomposite.

 

 

2D atomic layers beyond C

 

It is well known that dimensionality is one of the most defining parameter for materials, and two dimensional (2D) layered materials are of particular interest from both scientific and application  points of views  due to  their unique planar structures and properties. Due to their exceptional structural, physical, and chemical properties, 2D materials are expected to have significant impact on various applications, ranging  from  electronics to opto-electronics, sensors, catalysis, energy storage, gas separation, and protective coatings. Prompted by the blossoming research in graphene, people started to explore and isolate other layered  materials!such as nitrides, sulfides, selenides, tellurides, and oxides-as 2D atomic sheets. Earlier theoretical  and experimental work have shown that unprecedented physical properties were  also possible in most of  the  layered materials by reducing the thickness of their 3D crystal counterparts, such as in hexagonal boron nitride ( h -BN) which is starting to become another fascinating material in this area.  This breakthrough has opened  up the possibility of isolating and exploring the fascinating properties of atomic layers beyond graphene, which will offer functional flexibility, new properties and novel applications. our research are focusing on isolating/synthesizing 2D layered materials, developing techniques to structurally  characterize/chemically  modify/physically manipulate, as well as exploring several applications of new 2D layers for energy,  biomedicine and nanocomposite.

Nanodiamond

 

Nanodiamond (ND), formed by sp3-hybridized carbon atoms, is one member of the diverse structural  family  of nanocarbons. ND was accidentally discovered from the military explosive produced materials in  1963 by a  Russian group, in which graphite was irradiated with shock wave generated by detonation of explosives to  induce phase transition of graphitic carbon to diamond crystals. But for several reasons ND  was known  only  among a small number of scientists until the turn of the century. The most serious bottleneck was the fact that primary nanodiamond particles formed by the explosion are in general covalently bound together under high-temperature and high-pressure conditions to form large agglutinates, which were difficult to separate by  conventional methods. Recent studies have shown very high biocompatibility for nanodiamond, which make  ND gaining worldwide attentions. It is perspective that nanodiamond, the oldest known material  in new  attire, will begin to demonstrate a latent capability for becoming one of the major topics for  carbon  nanoscience and nanotechnology. Our research are focusing on the ND¨s selective preparation and isolation,  microstructure engineering, synchrotron radiation characterization, as well as developing  the sophisticated  and diversified applications for mechanical composite, new energy and biotechnology.

 

Synchrotron radiation techniques for Nanomaterials

Synchrotron radiation based techniques provide many advantages in nanomaterial characterization due to their energy tenability, high brightness, polarization, time structure and coherence. With the development of advanced light source, we are employing X-ray absorption fine structure (XAFS), scanning transmission X-ray microscopy (STXM), X-ray excited optical luminescence (XEOL) and angle-resolved photoelectron spectroscopy (APRES) to investigate our synthesized new nanomaterials in order to obtain their real time, in-situ and dynamic information, structures and properties.