1. Department of Chemistry Analytical Instruments Center Beijing Key Laboratory for Optical Materials and Photonic Devices Capital Normal University 105 North Road of Western Third Ring, Haidian District Beijing 100048 P. R. China
2. College of Science China Agricultural University Beijing 100193 P. R. China
3. School of Materials Science and Engineering Nankai University Tianjin 300350 P. R. China
4. MOE Key Laboratory of Pollution Processes and Environmental Criteria Tianjin Key Laboratory of Environmental Remediation and Pollution Control College of Environmental Science and Engineering Nankai University Tianjin 300350 P. R. China