1. Laboratory of Applied Environmental Chemistry (LAEC), University of Eastern Finland, Patteristonkatu 1, FI-50100 Mikkeli, Finland
2. Department of Chemistry, College of Science, Sultan Qaboos University, Muscat 123, Oman
3. Solar Energy Research Institute, National University of Singapore, Singapore 117574, Singapore
4. Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm, Sweden
5. Department of Chemical Engineering, Kwangwoon University, Seoul 139-701, Korea
6. Faculty of Technology, Lappeenranta University of Technology, Pateristonkatu 1, FI 50100 Mikkeli, Finland