Structural and coordination microenvironment regulated MOF with phosphorylurea group to boost uranium adsorption

Abstract

With the rapid industrial development and growing environmental awareness, the efficient extraction of uranium from seawater and wastewater has emerged as a research hotspot in nuclear energy development. Although metal–organic frameworks (MOFs) materials are widely used for uranium extraction, their low stability and poor selectivity hinder further development. Herein, a novel phosphorylurea functionalized metal–organic frameworks (MOFs) with optimized pore structure and hydrophilicity is fabricated (DUT-5-POR) by in situ induced etching strategy, which synergistically achieves the regulation of structural and coordination microenvironment. The presence of mesoporous pores can accelerate ion transport and expose abundant adsorption sites to enhance the adsorption capacity of uranium. Meanwhile, the introduction of phosphorylurea groups optimizes the hydrophilicity microenvironment and surface group density of DUT-5-POR to improve selectivity and kinetics. Consequently, DUT-5-POR shows an excellent adsorption ability (Qm = 263.4 mg⋅g−1) at pH = 6 and high selectivity for various competing metal ions, particularly in the separation of uranium and vanadium. Moreover, this work provides a feasible strategy for adjusting the structure and the coordination microenvironment of MOFs and a comprehensive perspective on the adsorption of uranium by MOF-based materials.