1. Qingdao Key Laboratory of Functional Membrane Material and Membrane Technology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, P. R. China
2. Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
3. Beijing University of Chemical Technology, Beijing 100029, P. R. China
4. Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, P. R. China