1. Faculty of Chemistry and Chemical Engineering, University of Maribor, Smetanova 17, SI-2000 Maribor, Slovenia
2. Department of Materials Synthesis, Jožef Stefan Institute, Jamova cesta 29, SI-1000 Ljubljana, Slovenia
3. Department of Environmental and Resource Engineering, Technical University of Denmark, Miljøvej 113, 2800 Kgs. Lyngby, Denmark