title: Structure, stability, and electronic interactions of polyoxometalates on functionalized graphene sheets.
abstract: Polyoxometalates (H(3)PMo(12)O(40), H(3)PW(12)O(40), H(4)PMo(11)VO(40)) supported on oxygen- and alkyl-functionalized graphene sheets were investigated. Discrete molecular species were directly observed by electron microscopy at loadings below 20 wt.%. The interaction between the polyoxometalates and the graphene surface was found to significantly impact their vibrational spectra and a linear correlation between the frequency of the M-O(c)-M vibration and the dispersion was evidenced by FTIR. While bulk-like electronic properties were observed for small aggregates (2-5 nm), UV-vis spectroscopy and cyclic voltammetry revealed changes in the electronic structure of isolated molecular species as a result of their interaction with graphene. Because of the ability to disperse alkyl-functionalized graphene in a variety of polar and nonpolar solvents, the materials synthesized in this work provide an opportunity to disperse polyoxometalates in media in which they would not dissolve if unsupported.
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, United States.
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Tessonnier
authors.forename: Stephanie
authors.initials: S
authors.lastname: Goubert-Renaudin
authors.forename: Shaun
authors.initials: S
authors.lastname: Alia
authors.forename: Yushan
authors.initials: Y
authors.lastname: Yan
authors.forename: Mark A
authors.initials: MA
authors.lastname: Barteau
mesh_terms: D004355:Drug Stability; D004583:Electrons; D006108:Graphite / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D008855:Microscopy, Electron, Scanning; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D017973:Tungsten Compounds / Q000737:chemistry*; D000099294:Polyoxometalates
chemical_list: D006108:Graphite; D010100:Oxygen; D017973:Tungsten Compounds; C102296:polyoxometalate I; D000099294:Polyoxometalates