title: Selective Imaging of Discrete Polyoxometalate Ions on Graphene Oxide under Variable Voltage Conditions.
abstract: Monosubstituted lacunary Keggin [CoSiW11O39](6-) ions on graphene oxide (GO) were used in a comparative imaging study using aberration corrected transmission electron microscopy at two different acceleration voltages, 80 and 200 kV. By performing a set of static and dynamical studies, together with image simulations, we show how the use of lower voltages results in better stability and resolution of the underlying GO support while the use of higher voltages permits better resolution of the individual tungsten atoms and leads to less kinetic motion of the cluster, thus leading to a more accurate identification of cluster orientation and better stability under dynamical imaging conditions. Applying different voltages also influences the visibility of both GO and the lighter Co at lower or higher voltages, respectively.
authors.forename: Concha
authors.initials: C
authors.lastname: Bosch-Navarro
authors.affiliation: Department of Chemistry, University of Birmingham , Edgbaston, Birmingham B15 2TT, U.K.
authors.forename: Laura M
authors.initials: LM
authors.lastname: Perkins
authors.forename: Reza J
authors.initials: RJ
authors.lastname: Kashtiban
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Rourke
authors.affiliation: Department of Chemistry, University of Birmingham , Edgbaston, Birmingham B15 2TT, U.K.
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Shannon
authors.forename: Jeremy
authors.initials: J
authors.lastname: Sloan
keywords: electron microscopy; graphene oxide; lacunary ion; polyoxometalate