1. State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, China
2. Key Laboratory of Coal Science and Technology, Taiyuan University of Technology, Taiyuan 030024, China
3. Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
4. School of Materials Science and Engineering, Wuhan Institute of Technology, Wuhan 430073, China