Dynamic Motion of Ru-Polyoxometalate Ions (POMs) on Functionalized Few-Layer Graphene

Datum: 4 oktober 2013

Locatie: Electron Microscopy for Materials Science (EMAT) - Groenenborgerlaan 171 - 2020 Antwerp

Tijdstip: 11.30 - 12.30 uur

Organisatie / co-organisatie: Electron Microscopy for Materials Science

Korte beschrijving: Friday-Lecture, Seminar. Speaker: Xiaoxing Ke, Electron Microscopy for Materials Science, University of Antwerp



Abstract: Dynamic Motion of Ru-Polyoxometalate Ions (POMs) on Functionalized Few-Layer Graphene

The interaction and stability of the tetraruthenate oxo-cluster {Ru4(μ-O)4(μ-OH)2(H2O)4[γ-SiW10O36]2}10-(Ru4POM) on few layer graphene (FLG) functionalized with positively charged ammonium pendants is studied via time-dependent imaging using an aberration-corrected transmission electron microscope (AC-TEM). Under the 80 kV irradiation of the electron beam the Ru4POM demonstrates dynamic motion on the graphene surface. The motion of the Ru4POM is captured as a series of images and is shown to vary as a function of time under certain constraints in the Ru4POM rotation. The frequency and amplitude of rotation is found to be related to the nature of the functional group used, including a polyamine dendron and a N,N,N-trimethyl benzenaminium moiety in our study. Distortions in the Ru4POM structure are revealed as well, suggesting that the ions can stand instantaneous structural changes without losing their integrity. The stability of the Ru4POM-graphene hybrid during the imaging corroborates the long-term robustness of the functional material applied to multielectronic catalytic processes.