1. Centre for Hydrogenergy College of Materials Science and Technology Nanjing University of Aeronautics and Astronautics Nanjing Jiangsu 210016 P. R. China
2. Hebei Provincial Laboratory of Inorganic Nonmetallic Materials College of Materials Science and Engineering North China University of Science and Technology Tangshan Hebei 063210 P. R. China
3. Department of Chemistry and Materials Science College of Science Nanjing Forestry University Nanjing Jiangsu 210037 P. R. China
4. TJU-NIMS International Collaboration Laboratory School of Material Science and Engineering Tianjin University Tianjin 300072 P. R. China
5. International Center for Materials Nanoarchitectonics (WPI-MANA) National Institute for Materials Science (NIMS) Tsukuba Ibaraki 305-0044 Japan