1. School of Chemical and Materials Engineering, Zhenjiang College, Zhenjiang 212003, P. R. China
2. School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, P. R. China
3. Jiangsu Key Laboratory for Environment Functional Materials, Suzhou University of Science and Technology, Suzhou 215009, P. R. China
4. Department of Physics, Jiangsu University, Zhenjiang 212013, P. R. China