Synthesis of new compounds involving layered titanates and niobates with copper(II)

series of titanates and niobates, K2Ti4O9, Na2Ti3O7, KNb3O8, K4Nb6O17, and their respective acid forms were prepared and characterized by X-ray diffra ction, thermogravimetry and scanning electron microscopy. The ion exchange capacity of the alkaline and acid forms towards Cu(II) was studied and it i s concluded that, as general behavior, the alkaline titanates and niobates have a higher ion exchange capacity towards copper cations than their respe ctive acid forms. Furthermore, the sodium matrix Na2Ti3O7 exhibits the high est ion exchange capacity of 3.00 mmol g(-1). Based on the thermogravimetri c results, the Cu(II) cation is coordinated to two water molecules when ads orbed on the titanate and niobate matrices. (C) 2001 Elsevier Science B.V: All rights reserved.