1. a Department of Mechanical Engineering , National University of Singapore , 2 Engineering Drive 3, 117576 , Singapore
2. b Health Care and Energy Materials Laboratory, E3-05-14, NUS Nanoscience and Nanotechnology Initiative, Faculty of Engineering, National University of Singapore , 2 Engineering Drive 3, 117576 , Singapore
3. c Environment and Water Technology Centre of Innovation, Ngee Ann Polytechnic , 535 Clementi Road, 599489 , Singapore
4. d NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore , 2 Engineering Drive 3, 117576 , Singapore
5. e King Saud University , 11451 , Riyadh , Kingdom of Saudi Arabia