1. Department of Physics and Nano Science and Technology Program, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
2. School of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, United Kingdom
3. Environmental Science Program, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
4. College of Communication Engineering, Chongqing University, Chongqing 400044, China