1. College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, P. R. China
2. College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai 201620, P. R. China
3. College of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan 030024, P. R. China
4. College of Materials Science and Engineering, Changsha University of Science and Technology, Changsha 410114, P. R. China