1. Department of Physics and TcSUH, University of Houston, Houston, Texas 77204, USA
2. Hubei Key Laboratory of Pollutant Analysis and Reuse Technology and School of Physics and Electronic Science, Hubei Normal University, Huangshi, Hubei 435002, China
3. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
4. Department of Chemistry, University of Houston, Houston, Texas 77204, USA
5. Center for Advanced Materials and Energy, Xihua University, Chengdu, Sichuan 610039, China