作者机构:[1]College of Chemistry, Chemical Engineering and Material Science, Shandong Normal University, Jinan 250014, China
相关基金:This work was supported by the National Natural Science Foundation of China ( No.:60671010, 20775045 ) and Natural Science Foundation of Shandong Province (Y2006B29). The authors wish to thank Prof. D.R. Chen and Mr. H.F. Shao for the help in measurements of XRD and XPS, respectively.