1. MOE Key Laboratory of Pollution Processes and Environmental CriteriaTianjin Key Laboratory of Environmental Remediation and Pollution ControlCollege of Environmental Science and EngineeringNankai University Tianjin 300350 P. R. China
2. School of Materials Science and EngineeringNankai University Tianjin 300350 P. R. China
3. Tianjin Key Laboratory of Molecular Optoelectronic SciencesDepartment of ChemistrySchool of ScienceTianjin UniversityCollaborative Innovation Center of Chemical Science and Engineering Tianjin 300072 P. R. China
4. Beijing Synchrotron Radiation Facility, Institude of High Energy PhysicsChinese Academy of Sciences Beijing 100049 P. R. China