1. School of Materials Science and Engineering; Key Laboratory of Nonferrous Metal of Ministry of Education, Central South University, Changsha, China;
2. Department of Environmental Engineering, School of Metallurgy and Environment, Central South University, Changsha, China;
3. Chinese National Engineering Research Center for Control and Treatment of Heavy Metal Pollution (CNERC-CTHMP), Changsha, China;
4. Key Laboratory of Catalysis and Materials Science of the State Ethnic Affairs Commission & Ministry of Education, South-Central University for Nationalities, Wuhan, P. R. China