基金Acknowledgments: This work was supported by the National Natural Science Foundation of China (No. 20673042), the Natural Science Foundation of Anhui Provincial Education Committee (No. K12007B014), the Natural Science Foundation of Anhui Province (No. 070415211), China Postdoctoral Science Foundation (No. 2004036511), the Laboratory Open Foundation of Green Materials Chemistry (No. KLSF(I)09), and the Laboratory Open Foundation of Guangdong Public Laboratory of Environmental Science and Technology. The authors thank Mr. LUO S. M., Mr. CHEN D. Z., and Mr. TAO Q. for their assistance.