1. Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation, Hunan Provincial Key Laboratory of Cytochemistry, School of Chemistry and Chemical Engineering, Changsha University of Science and Technology, Changsha 410114, China
2. School of Material Science and Engineering, Guilin University of Electronic Technology, Guilin 541004, China
3. Department of Chemistry and Bioscience, Aalborg University, DK-9220 Aalborg East, Denmark