• 文献标题:   Evidence for Charge Transfer at the Interface between Hybrid Phosphomolybdate and Epitaxial Graphene
  • 文献类型:   Article
  • 作  者:   HUDER L, RINFRAY C, ROUCHON D, BENAYAD A, BARAKET M, IZZET G, LIPPBREGOLIN F, LAPERTOT G, DUBOIS L, PROUST A, JANSEN L, DUCLAIROIR F
  • 作者关键词:  
  • 出版物名称:   LANGMUIR
  • ISSN:   0743-7463
  • 通讯作者地址:   Univ Grenoble Alpes
  • 被引频次:   8
  • DOI:   10.1021/acs.langmuir.6b00870
  • 出版年:   2016

▎ 摘  要

The interfacing of polyoxometalates and graphene can be considered to be an innovative way to generate hybrid structures that take advantage of the properties of both components. Polyoxometalates are redox-sensitive and photosensitive compounds with high temperature stability (up to 400 degrees C for some), showing tunable properties depending on the metal incorporated inside the complex. Graphene has a unique electronic band structure combined with good material properties for electrical and optical applications. The spontaneous, rather than electrochemical, functionalization of epitaxial graphene on SiC with Keggin phosphomolybdate derivative TBA(3) [PMo11O39 {Sn(C6H4) C equivalent to C (C6H4)N-2}] (named K-Sn(Mo)[N-2(+)]) bearing a phenyl diazonium unit is investigated. Graphene decoration is evidenced by means of AFM, Raman, XPS, and cyclic voltammetry, indicating a successful immobilization of the polyoxomolybdate. The covalent bonding of the polyoxometalate to the graphene substrate can be deduced from the appearance of a D band in the Raman spectra and from the loss of mobility in the electrical conduction. High-resolution XPS spectra reveal an electron transfer from the graphene to the Mo complex. The comparison of charge-carrier density measurements before and after grafting supports the p-type doping effect, which is further evidenced by work function UPS measurements.