1. College of Chemistry and Chemical Engineering, Xinyang Normal University, Xinyang, Henan 464000, P. R. China
2. Henan Province Key Laboratory of Utilization of Non Metallic Mineral in the South of Henan, Xinyang Normal University, Xinyang, Henan 464000, P. R. China
3. State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering, Ningxia University, Yinchuan 750021, P. R. China