催化剂对炭黑转变为纳米炭微球和碳管的影响
Transformation of carbon black into carbon nano-beads and nanotubes: the effect of catalysts
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摘要: 以二茂铁和二茂镍为催化剂, 采用化学气相沉积法在1000℃下,炭黑 (CB)转变为炭纳米微球和碳管。利用XRD, SEM, TEM, HR-TEM 和 Raman等对样品进行表征。结果表明,二茂铁和二茂镍质量比不同,可得到形貌不同的纳米炭的结构。与单金属催化剂相比,采用双金属催化剂合成的纳米炭结构具有高结晶度。催化剂颗粒填充在碳管内部或包裹在碳管外部,主要取决于催化剂与炭黑的质量比。当炭黑:二茂铁:二茂镍为1:2:2时,得到结晶度高的催化剂包裹多壁纳米炭微球结构。Abstract: Structural transformation of carbon black (CB) into carbon nano-beads and nanotubes was achieved at 1 000 ℃ using ferrocene and nickelocene as catalyst precursors using a simple and single step chemical vapor deposition method. The samples were characterized by XRD, SEM, TEM, HR-TEM and Raman spectroscopy. Results indicate that different morphological and high quality nano carbon structures were obtained using different weight ratios of catalyst to precursor. The use of bimetallic catalysts provides many different morphologies and a higher degree of crystal order of the carbon nanostructures than the use of mono-metallic catalysts. The nanotubes were mostly filled with metal nanoparticles and the degree of metal-filling is dependent on the weight ratio of catalyst precursor to CB. Metal-filled multi-walled carbon nano-bead structures with a high degree of crystalline order are also obtained at weight ratios of CB:ferrocene:nickelocene of 1:2:2.