1. School of Chemical Engineering, Sungkyunkwan University, Suwon 440-746, Korea
2. Energy Research Institute @ Nanyang Technological University (NTU) (ERI@N), Research Techno Plaza, X-Frontier Block, Level 5, 50 Nanyang Drive, 637553 Singapore
3. School of Materials Science and Engineering, Nanyang Technological University (NTU), 50 Nanyang Avenue, 639798 Singapore