1. School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031, China
2. School of Materials Science and Engineering, Southwest Jiaotong University, China
3. Department of Chemistry and Physics, Fayetteville State University, Fayetteville, NC 28301, United States
4. Department of Chemistry and Physics, Fayetteville State University, Fayetteville, NC, United States