1. Department of Chemistry, University of Ioannina, GR-45110 Ioannina, Greece
2. Department of Physics, University of Ioannina, GR-45110 Ioannina, Greece
3. Department of Chemical Engineering, University of Patras, GR-26504 Patras, Greece
4. University Research Center of Ioannina (URCI), Institute of Materials Science and Computing, GR-45110 Ioannina, Greece