[Zhan, Faqi; Li, Jie; Li, Wenzhang; Liu, Wenhua] Cent S Univ, Sch Chem & Chem Engn, Changsha 410083, Peoples R China.
[Zhan, Faqi; Li, Jie; Li, Wenzhang; Liu, Wenhua] Key Lab Hunan Prov Met & Mat Proc Rare Met, Changsha 410083, Peoples R China.
[Yang, Yahui] Hunan Agr Univ, Coll Resources & Environm, Changsha 410128, Hunan, Peoples R China.
[Li, Yaomin] UCL, Dept Chem, 20 Gordon St, London WC1H 0AJ, England.