Zilong Liu: Mapping the the oxygen configuration on single graphene oxide sheets

posted 11 Jul 2017, 06:42 by info admin
Zilong Liu, Kasper Nørgaard, Marc H. Overgaard, Marcel. Ceccato, Susan L.S. Stipp, and Tue Hassenkam*

Nano-Science Center,
Department of Chemistry, 
University of Copenhagen
Universitetsparken 5, 2100 Copenhagen, Denmark

As one of the main precursors of graphene-related materials, Graphene Oxide (GO) has sparked a heightened interest in a wide range of applications. Critical for these applications are the type of oxygen bond and its spatial distribution on the individual GO sheets. This distribution is not yet well understood. Few techniques offer a resolution high enough to unambiguously identify oxygen configuration. In this work, we provide a novel and label-free spectroscopic technique to map functional group distributions on GO, with higher spatial resolution and chemical specificity using AFM-based infrared nanospectroscopy (AFM-IR). Overcoming conventional IR diffraction limit, the new technique can obtain high spatial resolution at a nanometric level as well as chemical maps that are coupled to topography.We have directly observed oxygen bonding preferentially on areas where graphene is folded, in discrete domains and on edges of GO. lts have interesting implications. Determining atomic position and configuration from precise imaging offers the possibility to link nanoscale structure and composition with material function, paving the way for targeted tethering of ions, polymers and biomaterials.   

Zilong Liu is currently an PhD student of Department of Chemistry at the University of Copenhagen. He is primarily interested in characterizing and investigating properties of atomically thin materials such as graphene, carbon nanotube. He received his M.S. degree in Materials Science and Engineering from China University of Petroleum (2015)  where he used the Molecular Dynamics and DFT calculations to study the self-assembly of functionalized graphene and its gas adsorption and separation effect. His awards include Outstanding Master Graduation Thesis of Shandong Province (2016), Outstanding Master Graduate Students of Shandong Province (2015), One of ‘Ten Outstanding Academic Students’ in China University of Petroleum (2014).