1. Department of Applied Chemistry, School of Engineering, University of Toyama, Gofuku 3190, Toyama 930-8555, Japan
2. Key Lab of Applied Chemistry of Zhejiang Province and Department of Chemistry, Zhejiang University, Hangzhou 310007, China
3. National Energy Group Ningxia Coal Industry Co., Ltd., No.168 Beijing Middle Road, Yinchuan 750011, China