Selectivity of Transition Metal ions by a Layered Tin Phosphate

• Layered ammonium tin phosphate (SnP) with unusually large d-spacing was synthesized. • This Layered material can selectively separate transition metal ions from wastewater. • Ion-exchange capacity (C) sequence of SnP was found to be: C Cu > C Zn > C Ni ≈ C Mn. • SnP is highly useful for separation of transition metal ions from wastewater. A unique layered ammonium tin phosphate (NH 4 + -SnP) with unusually large d-spacing (16.57 Å) exhibited high uptake of transition metal ions compared with other common ion-exchangers from solutions containing large concentration of competing ions of Na + , K + , Mg 2+ and Ca 2+ . The ion-exchange capacity (C) sequence of NH 4 + -SnP was found to be: C Cu > C Zn > C Ni ≈ C Mn . This NH 4 + -SnP material is potentially useful for removal of transition metal ions from wastewater for remediation or recovery.