1. CAS Center for Excellence in Nanoscience Beijing Key Laboratory of Micro‐nano Energy and Sensor Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of Sciences Beijing 100083 P. R. China
2. School of Nanoscience and Technology University of Chinese Academy of Sciences Beijing 100049 P. R. China
3. Department of Civil Engineering Monash University Clayton 3800 Australia
4. School of Materials Science and Engineering Georgia Institute of Technology Atlanta GA 30332‐0245 USA