Exploration of carbon nanomaterials and their growth dynamics by the control of high-temprature state

在高达0.9 MPa的高压惰性气体中对碳材料进行激光汽化，可以制备出新型纳米碳。限制激光汽化碳并保持其高温会导致各种纳米碳的生长。通过热石墨化制备了100-1000 nm的多面体石墨（PG）颗粒，收率高达90%。对于激光汽化，将连续波Nd:YAG激光器的激光束聚焦在充满0.9 MPa氮气或CF_4气体的腔室内的石墨靶上。3人或1人的公司。x射线光电子能谱分析发现PG中有%的N或F原子。我们还发现，1 at的共存促进了PG和球囊状碳颗粒的形成。%硅。有十种元素的金属与碳一起在氩气环境中激光汽化2s。所得产物为杂化的单壁碳纳米角（SWNH）颗粒和其他纳米碳材料。通过控制氩气压力和激光辐照Fe， Co, Ni， Cu和Ag石墨靶中的元素含量，我们可以制备出含金属或含碳化物的碳纳米胶囊（CNCs），收率约为70%。在相同的加工条件下，B、Al、Si、Y和Gd没有形成杂化的SWNH颗粒，而是形成多壁碳纳米管（MWNTs）、碳化物丝等。我们研究了SWNH颗粒和CNC杂化结构的金属依赖性和高产率生长。激光汽化金属也可用于制备纳米碳复合材料。采用激光汽化Cu和Ti对MWNTs进行了改性。

Laser vaporization of carbon materials in high pressure inert gas (up to 0.9 MPa) can produce novel nanocarbon. Confining laser-vaporized carbon and maintaining its high temperature result in the growth of various nanocarbon. We have conducted the fabrication of polyhedral graphite (PG) particles of 100-1000 nm with a high yield (>90%) through thermal graphitization. We have also succeeded in generating nitrogen or fluorine containing PG. For laser vaporization, the laser beam from a continuous wave Nd:YAG laser was focused onto a graphite target in a chamber filled with N_2 or CF_4 gas of 0.9 MPa. Incorporations of 3 or 1 at. % of N or F atoms in PG were found from x-ray photoelectron spectroscopy. We also found the enhanced formation of PG and balloon-like carbon particles achieved by the coexistence of 1 at.% silicon.Metals of ten elements were laser-vaporized with carbon for 2 s into an Ar gas atmosphere. The products obtained were hybridized single-wall carbon nanohorn (SWNH) particles and other nanocarbon materials. Controlling the Ar gas pressure and the element content in a laser-irradiation graphite target for Fe, Co, Ni, Cu, and Ag enabled us to fabricate SWNH particles including metal- or carbide-containing carbon nanocapsules (CNCs) with the high yield of approximately 70%. Under the same processing conditions, B, Al, Si, Y, and Gd did not form hybridized SWNH particles and formed multi-wall carbon nanotubes (MWNTs), carbide wires, etc. We investigated the metal-dependent and high-yield growth of the hybrid structure of the SWNH particle and the CNC. Laser vaporization of metal was also useful to produce nanocarbon composites. MWNTs were modified by laser vaporization of Cu and Ti.