Adsorptive removal of Sb(V) from water using a mesoporous Zr-based metal-organic framework

The adsorption and removal of Sb(OH)(6)(-) from water using the water stable Zr-6-based MOF, NU-1000, is explored. The adsorption capacity and uptake time of Sb(OH)(6)(-) in NU-1000 is measured at varying concentrations to determine an overall maximum adsorption capacity of 260 mg of Sb(OH)(6)(-) per g of MOF, corresponding to 2.5 Sb(OH)(6)(-) per node of NU-1000 and exhibiting the highest adsorption capacity of any material reported to date for Sb(V) removal. Differential pair distribution function (dPDF) analysis of total X-ray scattering data reveals that Sb(OH)(6)(-) interacts in an eta(2)mu(2) fashion with the Zr-6-node of NU-1000, and that as the amount of Sb(OH)(6)(-) adsorbed increases, the interaction between the analyte and the node becomes stronger. Post-adsorption characterization shows that NU-1000 remains stable throughout the adsorption process. (C) 2018 Elsevier Ltd. All rights reserved.