1. School of Chemistry and Chemical Engineering, North Minzu University, Yinchuan 750021, P. R. China
2. Key Laboratory of Chemical Engineering and Technology (North Minzu University), State Ethnic Affairs Commission, Yinchuan 750021, P. R. China
3. Ningxia Key Laboratory of Solar Chemical Conversion Technology Autonomous Region, North Minzu University, Yinchuan 750021, P. R. China