• 文献标题:   Crystalline Transformation of Colloidal Nanoparticles on Graphene Oxide
  • 文献类型:   Article
  • 作  者:   PAK C, LEE DC
  • 作者关键词:   graphene oxide, colloidal nanocrystal, hybrid composite material, transformation
  • 出版物名称:   ACS APPLIED MATERIALS INTERFACES
  • ISSN:   1944-8244
  • 通讯作者地址:   Korea Adv Inst Sci Technol
  • 被引频次:   10
  • DOI:   10.1021/am201666q
  • 出版年:   2012

▎ 摘  要

Emergence of novel two-dimensional (2-D) templates, e.g., graphene oxide, has signified new intriguing opportunities to couple nanocrystals electronically to the microscopic 2-D contacts. A promising approach to uniform dispersion of inorganic nanocrystals on the 2-D interfaces is to graft them through chemical bonding. The 2-D dispersion would offer a unique opportunity to address one of the primary challenges in the field of nanotechnology: fulfilling excellent chemical and physical properties of the nanocrystals in electronic solid-state devices. In this study, we blended I colloidal nanocrystals with graphene oxide in aqueous solution in attempts to bind the nanocrystals on reactive sites of the graphene oxide surface, thereby achieving uniform loading. Interestingly, the nanocrystals undergo significant crystalline transformation even under relatively moderate reaction conditions. The growth of particle size and the drastic crystalline deformation, e.g., from wurtzite CdSe to amorphous Se, appear to take place in the proximity of acidic functional groups on graphene oxide. Photocarriers also play a key role in the reaction: under room light, the transformation yielded dramatic size increase and crystalline transformation, whereas in the dark, the change was suppressed. The experimental results presented in this study provide guidelines for uniform 2-D loading of colloidal nanocrystals on graphene oxide. The findings suggest that the surface acidity be titrated for colloidal nanocrystals to deposit on the graphitic layer and to avoid unwanted changes of nanocrystal size and properties.