| Inspired by the discovery of carbon nanotubes, there has been great interest in the synthesis of low-demensional nanostructures, due to their unique structure characteristics, fascinate properties and potential applications in the fields such as optical, electrical, magnetic, medical science and et al.This paper focus on the synthesis of low-demensional nanostructures via pyrolysis of polymeric precursors with tailored atmospheres, to realize the growth of nanostructures in a controlled manner. The synthesized nanostructures have been systematically characterized by by Scan Electron Microscopy (SEM), X-Ray Diffraction (XRD), Transition Electron Microscopy (TEM), High-resolution Transition Electron Microscopy (HRTEM), photoluminescence (PL) and Raman. Based on the present work, the research progresses have been made as bellow:(1) SiC nanocrystals were obtained via directly pyrolysis of polysilazane (PSN) at1350℃for90min in vacuum. The obtained SiC nanoparticles are of pure3C-SiC and well crystallized with an average size of～100nm.(2) Carbon nanotubes with large diameter were fabricated via Cu catalyst assisted pyrolysis of polymethylMethacrylate (PMMA) as carbon source at600℃for20min in vacuum. The resultant carbon nanotue are characterized as one end of carbon nanotube being open and the other end is convergent slowly. The nanotubes are sized in～100-200nm in diameters and～500nm in lengthes. The growth mechanism of the obtained carbon nanotubes was proposed as the bottom growth mode.(3) Epitaxial growth of graphene was achieved on Cu substrate in the mixture atmosphere of Ar and H2with PMMA as the carbon source. Large area and free standing graphene could be grown by epitaxial growth on Cu particles and films at800℃for5min. Synthesis of graphene nanobelts with continuous and large area have been accomplished on the ribbon-like Cu film at800℃without holding time and with a cooling rate of8℃/min to the room temperature. |
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