1. Department of Physics, Southeast University, Nanjing, 211189, People’s Republic of China
2. Department of Building and Construction, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, People’s Republic of China
3. Institute of Textiles and Clothing, Hong Kong Polytechnic University, Kowloon, Hong Kong, People’s Republic of China
4. Department of Chemistry and Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, Nebraska 68588