1. Faculty of Chemistry, University of Duisburg-Essen and Center for Nanointegration Duisburg-Essen, Universitätsstrasse 5−7, S07 S03 C30, D-45117 Essen, Germany
2. Interdisciplinary Center for Analytics on the Nanoscale (ICAN), NanoEnergieTechnikZentrum, Carl-Benz-Strasse 199, D-47057 Duisburg, Germany