1. School of Chemistry and Chemical Engineering Centre for Environment and Water Resource Central South University Lushannan Road 932 410083 Changsha P. R. China
2. Department of Materials and Chemical Engineering Hunan Institute of Technology Henghua Road 18 421002 Hengyang P. R. China
3. Institut für Anorganische Chemie Universität Göttingen Tammannstrasse 4 37077 Göttingen Germany