• 文献标题:   Toward Combining Graphene and QDs: Assembling CdTe QDs to Exfoliated Graphite and Nanographene in Water
  • 文献类型:   Article
  • 作  者:   KATSUKIS G, MALIG J, SCHULZDROST C, LEUBNER S, JUX N, GULDI DM
  • 作者关键词:   nanographene, exfoliated graphite, cdte quantum dot, timeresolved spectroscopy, electron transfer
  • 出版物名称:   ACS NANO
  • ISSN:   1936-0851 EI 1936-086X
  • 通讯作者地址:   Univ Erlangen Nurnberg
  • 被引频次:   60
  • DOI:   10.1021/nn204700z
  • 出版年:   2012

▎ 摘  要

Herein, we report for the first time on a full-fledged investigation of water-soluble (die quantum dots (QD) that are immobilized onto exfoliated graphite (EG) and/or nanographene (NG). Particular emphasis was placed on a top-down preparation of stable aqueous dispersions-starting from natural graphite rather than graphene oxide-while preserving the intrinsic properties of graphene. To this end, we circumvented the harsh conditions commonly employed for the pre-exfoliation (i.e., Hummers method). First, a hydrophobic-hydrophobic/pi-pi stacking motif was tested between EG and pyrene, to which QDs are covalently attached (QD-pyrene). Second, we employed the combination of hydrophobic-hydrophobic/pi-pi stacking and electrostatic interactions to build up hierarchical structures composed of NG, positively charged pyrene (pyrene(+)), and negatively charged QDs. The novel nanohybrids-QD-pyrene/EG and QD/pyrene(+)/NG-were characterized with specific emphasis on electron-transfer chemistry. In fact, both assays provide kinetic and spectroscopic evidence that support electron transfer dynamics that vary, however, between EG and NG as a reflection of the different degree of graphite exfoliation.