• 文献标题:   Electrochromic Graphene Molecules
  • 文献类型:   Article
  • 作  者:   JI ZQ, DOORN SK, SYKORA M
  • 作者关键词:   graphene molecule, nanographene, graphene, graphene quantum dot, electrochemistry, spectroelectrochemistry, electrochromism
  • 出版物名称:   ACS NANO
  • ISSN:   1936-0851 EI 1936-086X
  • 通讯作者地址:   Los Alamos Natl Lab
  • 被引频次:   11
  • DOI:   10.1021/acsnano.5b00093
  • 出版年:   2015

▎ 摘  要

Polyclic aromatic hydrocarbons also called Graphene Molecules (GMs), with chemical composition C132H36(COOH)(2) were synthesized in situ on the surface of transparent nanocrystalline indium tin oxide (nc-ITO) electrodes and their electronic structure was studied electrochemically and spectro-electrochemically. Variations in the potential applied onto the nc-ITO/GM electrodes induce only small changes in the observed current, but they produce dramatic changes in the absorption of the GMs, which are associated with their oxidation and reduction. Analysis of the absorption changes using a modified Nernst equation is used to determine standard potentials associated with the individual charge transfer processes. For the GMs prepared here, these were found to be E-1,ox(0) = 0.77 +/- 0.01 V and E-2,ox(0) = 1.24 +/- 0.02 V vs NHE for the first and second oxidation and E-1,red(0) = -1.50 +/- 0.04 V for the first reduction. The charge transfer processes are found to be nonideal. The nonideality factors associated with the oxidation and reduction processes are attributed to strong interactions between the GM redox centers. Under the conditions of potential cycling, GMs show rapid (seconds) color change with high contrast and stability. An electrochromic application is demonstrated wherein the GMs are used as the optically active component.