1. Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou 350207, China
2. Department of Chemistry, Faulty of Science, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
3. NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, University Hall, 21 Lower Kent Ridge Road, Singapore 119077, Singapore