1. School of Chemistry & Chemical Engineering, Henan University of Technology, Zhengzhou 450001, P. R. China
2. Tobacco Research Institute of China National Tobacco Company, Zhengzhou 450001, P.R. China
3. Henan Key Laboratory of Nanocomposites and Applications, Institute of Nanostructured Functional Materials, Huanghe Science and Technology College, Zhengzhou 450006, P. R. China