A novel strontium-based MOF: synthesis, characterization, and promising application in removal of ^152+154Eu from active waste

Abstract

Removal of hazardous radioactive materials such as ^152+154Eu from active waste using the batch approach has attracted attention nowadays. In this work, a novel melamine-terephthalic strontium metal-organic framework (MTSr-MOF) was prepared <i>via</i> a hydrothermal method. The MTSr-MOF was characterized by various analytical techniques such as FT-IR, ¹H/¹³C-NMR, mass spectroscopy, XPS, XRD, TGA, BET, FE-SEM/EDX, TEM, and UV. The obtained data revealed that MTSr-MOF exhibited brick-like building blocks that were bridged together by the linkers, and each block had a thickness of ∼120 nm. The BET surface area was 74.04 m² g^-1. MTSr-MOF was used for the removal of ^152+154Eu radionuclides from active waste. Further functionalization using various modifiers, including oxalic acid, EDTA, sulfuric acid, and sodium hydroxide was carried out to improve the sorption efficiency of MTSr-MOF towards ^152+154Eu radionuclides. Among them, MTSr-MOF modified with oxalic acid (MTSr-OX-MOF) demonstrated a superior removal efficiency toward ^152+154Eu radionuclides when compared to MTSr-MOF or other published reports, with a removal efficiency of more than 96%. The higher sorption efficiency of the MTSr-OX-MOF indicates that it could be a promising candidate for the removal of ^152+154Eu radionuclides from radioactive waste.