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 National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore
3. Nanoyang Group State Key Laboratory of Chemical Engineering School of Chemical Engineering and Technology Tianjin University Tianjin 300072 China
4. Key Laboratory of Resource Chemistry of Ministry of Education Shanghai Key Laboratory of Rare Earth Functional Materials Department of Chemistry Shanghai Normal University Shanghai 200234 China
5. Department of Physics National University of Singapore 2 Science Drive 3 Singapore 117542 Singapore