• 文献标题:   A graphene sheet as an efficient electron acceptor and conductor for photoinduced charge separation
  • 文献类型:   Article
  • 作  者:   ZHANG XF, XI Q
  • 作者关键词:  
  • 出版物名称:   CARBON
  • ISSN:   0008-6223
  • 通讯作者地址:   Hebei Normal Univ Sci Technol
  • 被引频次:   62
  • DOI:   10.1016/j.carbon.2011.05.019
  • 出版年:   2011

▎ 摘  要

Tetrasulfonated zinc phthalocyanine (Pc) was bound to graphene (G) sheets by the pi-pi stacking supermolecular method. The few-layer graphene sheets were obtained by chemically reducing graphite oxide and characterized by AFM, IR and UV-vis absorption methods. Photoinduced electron transfer (PET) within the nano assembly is revealed by laser flash photolysis, time resolved and steady state fluorescence, as well as UV-vis absorption techniques. A graphene sheet can be attached by up to 52,000 Pc molecules to form a super molecule G(Pc)(52,000), in which many Pc molecules can be simultaneously photoexcited to the S(1) state. One graphene sheet can simultaneously quench thousands of excited Pcs with a large rate constant of the order of 10(16) M(-1) s(-1) by PET. A graphene sheet not only accepts electrons from the excited Pcs on it but also delivers the captured electrons to its unexcited Pcs to form (Pc(.+))(n)G(Pc(.-))(n), so that a large electron charge (i.e. n >> 1) is separated between unlinked Pc molecules with a small energy loss. These novel features of PET are explained by the following unique properties of graphene: (i) its excellent electron-transport and multi-electron-accepting ability, (ii) its multi-chromophore binding and concurrent multi-photon absorbing ability. (C) 2011 Elsevier Ltd. All rights reserved.