1. Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543 Singapore
2. Department of Chemistry, Yonsei University, Seoul 120-749, Korea
3. Key Laboratory of
Magnetic Materials and Devices,
Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
4. Institute of Materials Research
and Engineering, A*STAR, 3 Research Link, 117602 Singapore
5. Division of Physical Science and Engineering
and KAUST Catalysis Center, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
6. Department of Materials Science & Engineering, National University of Singapore, 119260 Singapore