1. School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, 62 Nanyang Drive, Singapore, 637459 Singapore
2. Institute of Sustainable Energy, Universiti Tenaga Nasional (UNITEN), Jalan IKRAM-UNITEN, 43000 Kajang, Selangor Darul Ehsan, Malaysia
3. College of the Environment and Ecology, Xiamen University, Xiamen, 361102, Fujian, PR China