1. School of Environment and Resource, Taiyuan University of Science and Technology, Taiyuan 030024, P. R. China
2. School of Materials Science and Engineering, North University of China, Taiyuan 030051, P. R. China
3. College of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, P. R. China
4. School of Mechanical Engineering, University of Western Australia, 35 Stirling Highway, WA 6009, Australia