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Publications in Scientific Journals:

M. Müllner, J. Balajka, M. Schmid, U. Diebold, S. Mertens:
"Self-Limiting Adsorption of WO3 Oligomers on Oxide Substrate in Solution";
Journal of Physical Chemistry C, 121 (2017), 19743 - 19750.



English abstract:
Electrochemical surface science of oxides is an
emerging field with expected high impact in developing, for
instance, rationally designed catalysts. The aim in such
catalysts is to replace noble metals by earth-abundant
elements, yet without sacrificing activity. Gaining an atomiclevel
understanding of such systems hinges on the use of
experimental surface characterization techniques such as
scanning tunneling microscopy (STM), in which tungsten
tips have been the most widely used probes, both in vacuum
and under electrochemical conditions. Here, we present an in
situ STM study with atomic resolution that shows how
tungsten(VI) oxide, spontaneously generated at a W STM tip,
forms 1D adsorbates on oxide substrates. By comparing the behavior of rutile TiO2(110) and magnetite Fe3O4(001) in aqueous
solution, we hypothesize that, below the point of zero charge of the oxide substrate, electrostatics causes water-soluble WO3 to
efficiently adsorb and form linear chains in a self-limiting manner up to submonolayer coverage. The 1D oligomers can be
manipulated and nanopatterned in situ with a scanning probe tip. As WO3 spontaneously forms under all conditions of potential
and pH at the tungsten−aqueous solution interface, this phenomenon also identifies an important caveat regarding the usability
of tungsten tips in electrochemical surface science of oxides and other highly adsorptive materials

Created from the Publication Database of the Vienna University of Technology.