1. Department of Applied Chemistry School of Engineering Tohoku University 6-6-07, Aoba, Aramaki, Aoba-ku Sendai 980-8579 Japan
2. College of Environmental Science and Engineering Institute of New Rural Development Tongji University 1239 Siping Road Shanghai 200092 P. R. China
3. Research Center for Artificial Photosynthesis Advanced Research Institute for Natural Science and Technology Osaka City University 3-3-138 Sugimoto, Sumiyoshi Osaka 558-8585 Japan