1. a Department of Chemistry , University of Copenhagen , Universitetsparken 5, Copenhagen Ø , DK-2100 , Denmark
2. b Center for Oxygen Microscopy and Imaging, Department of Chemistry , Aarhus University , Langelandsgade 140, Aarhus C , DK-8000 , Denmark
3. c Department of Physics, Chemistry and Pharmacy , University of Southern Denmark , Campusvej 55, Odense M , DK-5230 , Denmark