1. Shanxi Key Laboratory of Biomedical Metal Materials College of Materials Science and Engineering Taiyuan University of Technology Taiyuan 030024 P. R. China
2. National Graphene Products Quality Inspection and Testing Center (Jiangsu) Special Equipment Safety Supervision Inspection Institute of Jiangsu Province Yanxin Road 330 Wuxi 214174 P. R. China
3. Analytical Instrumentation Center State Key Laboratory of Coal Conversion Institute of coal chemistry Chinese Academy of Sciences Taiyuan 030001 P. R. China
4. College of Biomedical Engineering Taiyuan University of Technology Taiyuan 030024 P. R. China
5. College of Materials Science and Engineering Taiyuan University of Technology Taiyuan 030024 P. R. China
6. Shanxi Key Laboratory of Bone and Soft Tissue Injury Repair Department of Orthopedics Second Hospital of Shanxi Medical University Taiyuan 030001 P. R. China
7. Department of Physics Department of Materials Science and Engineering and Department of Biomedical Engineering City University of Hong Kong Tat Chee Avenue Kowloon Hong Kong P. R. China