1. School of Materials Science and EngineeringShenyang University of Technology Shenyang 110870 P. R. China
2. State Key Laboratory of Rare Earth Resource UtilizationChangchun Institute of Applied ChemistryChinese Academy of Science Changchun 130022 P. R. China
3. School of ChemistryChemical Engineering and Life Science and State Key Laboratory of Advanced Technology for Materials Synthesis and ProcessingWuhan University of Technology Wuhan 430070 P. R. China