1. Department of Chemistry City University of Hong Kong Kowloon Hong Kong 999077 P. R. China
2. Department of Chemistry Center of Super‐Diamond & Advanced Films (COSDAF) City University of Hong Kong Kowloon Hong Kong 999077 P. R. China
3. City University of Hong Kong Shenzhen Research Institute Shenzhen 518057 P. R. China
4. Department of Applied Physics The Hong Kong Polytechnic University Kowloon Hong Kong 999077 P. R. China
5. The Hong Kong Polytechnic University Shenzhen Research Institute Shenzhen 518057 P. R. China
6. Physics department and Jiangsu Key Laboratory for Chemistry of Low‐Dimensional Materials Huaiyin Normal University Huaian 223300 P. R. China
7. Department of Chemistry and State Key Laboratory of Marine Pollution City University of Hong Kong Kowloon Hong Kong 999077 P. R. China