1. College of Science Donghua University Shanghai 201620 P. R. China
2. Magnetic Confinement Fusion Research Center of Ministry Education Donghua University Shanghai 201620 P. R. China
3. Department of Environmental Science and Engineering University of Shanghai for Science and Technology Shanghai 200093 P. R. China
4. Institute of Photochemistry and Photocatalysts University of Shanghai for Science and Technology Shanghai 200093 P. R. China