乙醇火焰燃烧制备螺旋碳纳米纤维及结构分析

采用乙醇火焰燃烧, 借助于基板材料上涂敷锡盐作为催化剂前驱体, 制备了螺旋结构碳纳米纤维; 借助于扫描电子显微镜、透射电子显微镜、XRD和拉曼光谱等分析了螺旋碳纤维的形貌和结构. 螺旋碳纳米纤维螺旋直径约为100nm, 纤维直径约为50nm, 螺距约80nm. 螺旋碳纤维的石墨层方向基本垂直于轴向, 近似鱼骨型结构, 相邻碳层间距为0.34nm. 借助于高分辨电子显微镜分析了螺旋碳纳米纤维的形成机理, 认为碳原子沿催化剂SnO₂各晶面析出速度不同是形成螺旋碳纳米纤维的主要原因.

Morphology and Structure of Carbon Nanocoils Synthesized via the Flame Combustion of Ethanol

Carbon nanocoils (CNCs) were in situ synthesized by the flame combustion of ethanol using stannic chloride as catalyst precursor. The morphology and structure of CNCs were characterized by means of scanning electron microscope, transmission electron microscope, X-ray diffraction and Raman spectrum. The coil diameter of the CNCs is calculated to be ca. 100nm and its fiber diameter is 50nm with a pitch of ca. 80nm. The CNC develops along the direction of growth and comprises carbon layers that are peripheral and circulate around the axes of the fiber, similar to a fishbone and the interlayer spacing between carbon sheets is ca. 0.34nm. High-resolution transmission electron micrograph (HRTEM) analyse reveals that the crystal face (101) of SnO₂ is the most favored face for carbon precipitation and it is situated on the outer side of the CNCs, while crystal face (110) with the lowest carbon extrusion speed is situated on the inner side. The nonuniformity of the carbon extrusion speed at different crystal faces of the SnO₂ grain leads to the helical growth of the coil.