螺旋纳米碳纤维的制备与表征

利用氢电弧等离子体法制备了纳米铜-镍合金作为催化剂,通过乙炔的催化热解制备了对称生长的螺旋纳米碳纤维.并用扫描电子显微镜(SEM)、透射电子显微镜(TEM)和红外(IR)对其进行表征,发现在单个纳米铜-镍合金粒子上对称生长出两根螺旋纳米碳纤维,它们的旋向相反,但是具有相同的螺旋直径、螺旋长度和碳纤维直径,而且纳米铜-镍合金粒子也有各种不同的形状.此外,这两根对称生长的螺旋纳米碳纤维之间的夹角也不同,分别为60°,90°,110°和160°.IR结果表明,螺旋纳米碳纤维分子结构中既含有不饱和的CC双键,又含有饱和的-CH₂-和-CH₃-基团.然而,利用氢电弧等离子体法制备的纳米铜和纳米镍作为催化剂,催化热解乙炔,得到的产物均是直线型碳纤维.

Preparation and Characterization of Helical Carbon Nanofibers

Helical carbon nanofibers with a symmetric growth mode were synthesized by the catalytic decomposition of acetylene using Cu-Ni alloy nanoparticles as the catalyst prepared by hydrogen-arc plasma method. The morphology of the coiled carbon nanofibers was examined by SEM, TEM and IR. We found that there were only two helical fibers symmetrically grown over a single Cu-Ni alloy nanoparticle, which was faceted with a regular shape(quadrangular, oblong, triangular and rhombus). The two coiled fibers have different coiled chirality, but have identical coil diameter, coil length, and fiber diameter. The angles between the two helical fibers grown on a single catalyst nanoparticles were different(60°, 90°, 110° and 160°). The IR analysis revealed that the molecular structure of helical nanofibers contained both unsaturated —CC— and saturated —CH2— and —CH3— groups. However, rectilinear carbon fibers were synthesized by the catalytic decomposition of acetylene with Cu nanoparticles and Ni nanoparticles as the catalyst prepared by hydrogen-arc plasma method.