1. Engineering Technology Research Center of Henan Province for Solar, CatalysisCollege of Chemistry and Pharmaceutical EngineeringNanyang Normal University Nanyang 473061 P. R. China
2. College of Materials and Chemical EngineeringKey Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion MaterialsChina Three Gorges University Yichang 443002 P. R. China