1. CAS Key Laboratory of Design and Assembly of Functional Nanostructures; Fujian Provincial Key Laboratory of Nanomaterials; Fujian Institute of Research on the Structure of Matter; Chinese Academy of Sciences; Fuzhou 350002 P. R. China
2. State Key Laboratory of Structural Chemistry; Fujian Institute of Research on the Structure of Matter; Chinese Academy of Sciences; Fuzhou 350002 P. R. China
3. National Synchrotron Radiation Laboratory; University of Science and Technology of China; Hefei 230029 P. R. China
4. Center of Advanced Science and Engineering for Carbon (Case 4Carbon); Department of Macromolecular Science and Engineering; Cas Western Reserve University; 10900 Euclid Avenue Cleveland OH 44106 USA