酚醛树脂原位催化裂解制备低维碳纳米结构

以Ni（NO₃）₂·6H₂O为催化剂前躯体,原位催化裂解酚醛树脂制备了碳洋葱、竹节碳和碳纳米管等低维碳纳米结构;用粉体X-射线衍射（XRD）、扫描电镜（SEM）和透射电镜（TEM）等手段对低维碳纳米结构进行了表征。结果表明;当Ni（NO₃）₂·6H₂O与苯酚物质量比小于0.01时,Ni催化剂易分散,碳纳米管易生成,管径均一、分布稠密;当Ni（NO₃）₂·6H₂O与苯酚物质量比大于0.04时,Ni催化剂易团聚,碳纳米管管径分布较宽,分布稀疏;当Ni（NO₃）₂·6H₂O与苯酚物质量比为0.10时,Ni催化剂团聚现象严重,难以生成碳纳米管;提出了碳洋葱、竹节碳和碳纳米管不同碳纳米结构可能的形成机理。

Preparation of Low-dimension Carbon Nanostructures via in-situ Catalytic Pyrolysis of Phenolic Resin

Different low-dimension carbon nanostructures,such as onion-like carbon,bamboolike carbon and carbon nanotubes,were prepared via in-situ catalytic pyrolysis of phenolic resin with Ni（NO₃）₂·6H₂O as catalytic precursor,and characterized by X-ray diffraction,field-emission scanning electron microscope and transmission electron microscopy.The results show that carbon nanotubes with a narrow diameter distribution are more easily formed in a compact mass by a well dispersed Ni catalyst when the molar ratio of Ni（NO₃）₂··6H₂O to phenol is under 0.01.When the ratio of Ni（NO₃）₂·6H₂O to phenol is 0.04 above,Ni catalyst were prone to be aggregated,leading to a widened diameter distribution and sparse growth of carbon nanotube.When the ratio reached to 0.10,a more serious catalytic aggregation was observed and no carbon nanotube was prepared.The possible mechanisms were proposed for the formation of onion-like carbon,bamboo-like carbon and the carbon nanotube.