1. School of Chemistry and Chemical EngineeringHunan University of Science and Technology Xiangtan 411100 P. R. China
2. School of Chemistry and Chemical EngineeringShandong University Jinan 250100 P. R. China
3. Qingdao Institute of Bioenergy and Bioprocess TechnologyChinese Academy of Sciences No. 189 Songling Road Qingdao 266101 P. R. China
4. Center of Materials Science and Optoelectronics EngineeringUniversity of Chinese Academy of Sciences Beijing 100049 P. R. China