• 文献标题:   TiCx-Ti2C nanocrystals and epitaxial graphene-based lamellae by pulsed laser ablation of bulk TiC in vacuum
  • 文献类型:   Article
  • 作  者:   CAI KJ, ZHENG Y, SHEN P, CHEN SY
  • 作者关键词:  
  • 出版物名称:   CRYSTENGCOMM
  • ISSN:   1466-8033
  • 通讯作者地址:   Natl Sun Yat Sen Univ
  • 被引频次:   30
  • DOI:   10.1039/c4ce00358f
  • 出版年:   2014

▎ 摘  要

Nonstoichiometric delta-TiCx, delta'/delta"-Ti2C and 2-D turbostratic graphene-based lamellae were co-synthesized by pulsed laser ablation of bulk delta-TiC in a vacuum and characterized using X-ray diffraction, electron microscopy and optical spectroscopy. The predominant delta-TiCx occurred as submicron-sized particulates and nanocondensates with size dependent shapes (5 nm sphere vs. 10 and 15 nm cubo-octahedra), which tended to coalesce over well-developed (111) as a unit or impinged by the similar to(001) vicinal surface to form a [ 1 (1) over bar0] tilt boundary. The minor Ti2C nanocondensates occurred as cubo-octahedra for the cubic d'-phase and triangular plates with well-developed (0001), {1 (1) over bar 02} and {1 (1) over bar0 (4) over bar} faces for the trigonal delta"-phase, which tended to coalesce over (0001) as a unit. The turbostratic graphene-based lamellae occurred as nanoribbons or an artificial epitaxy shell on delta-TiCx and delta'/delta"-Ti2C to facilitate carbon vacancy diffusion. The present TiCx-Ti2C-graphene phase assembly with characteristic Raman modes sheds light on their natural dynamic occurrence in presolar settings. The bimodal UV-visible absorbances of this phase assembly in the form of nanoparticles may have potential photocatalytic and abrasive/ lubricant applications.