[1] Nanyang Technol Univ, Sch Phys & Math Sci, Div Chem & Biol Chem, Singapore 637371, Singapore
[2] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA
[3] King Abdulaziz Univ, Fac Sci, Dept Chem, Ctr Excellence Adv Mat Res, Jeddah 21598, Saudi Arabia
[4] Nanyang Technol Univ, Sch Mat Sci & Engn, Singapore 639798, Singapore