1. College of Science, Central South University of Forestry and Technology, Changsha 410004, Hunan, P.R. China
2. College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, Hunan, P.R. China
3. Chemistry Department, Murdoch University, Murdoch, WA 6150, Australia
4. School of Physics and Optoelectronic Engineering, Xidian University, Xi’an 710071, Shanxi, P.R. China