1. High Voltage Laboratory, Electrical and Computer Engineering Department, University of Patras, 26504 Rion, Patras, Greece
2. Surface Science Laboratory, Chemical Engineering Department, University of Patras, 26504 Rion, Patras, Greece
3. Laboratory of Inorganic and Analytical Chemistry, Chemical Engineering Department, University of Patras, 26504 Rion, Patras, Greece
4. Institute of Chemical Engineering Sciences (ICES)-FORTH, Rion 26504, Greece