Efficient, Reversible Lead Adsorption in a Thiol‐Decorated Zirconium‐Metal–Organic Framework

Metal-organic frameworks (MOFs) featuring high densities of selective metal binding sites represent promising materials for the extraction of toxic metal ions from liquids. This study presents a Zr-MOF containing accessible thiol functionalities that demonstrates exceptional adsorption capacity and recyclability for the capture of lead(II) ions (Pb(II)). Structural characterization via Pair Distribution Function (PDF) and Powder X-ray diffraction (PXRD) analyses revealed well-defined Zr-clusters interconnected via meso-2,3-dimercaptosuccinic acid (DMSA) linkers. The framework exhibits limited long-range structural order and high ligand flexibility that facilitates Pb(II) chelation. Sequential adsorption/desorption cycles monitored via X-ray Photoelectron Spectroscopy (XPS), solid-state NMR, and PDF established that: (i) strong chelation occurs between Pb(II) and DMSA through both thiol and carboxylate functionalities and (ii) this chelation is reversible under acidic conditions, enabling complete adsorbent regeneration. Beyond its high performance in lead removal from water, the practical utility of Zr-DMSA was further demonstrated through the removal of Pb(II) from damaged Pb-based perovskite solar cells, with efficacy confirmed at both ambient and elevated temperatures. These results highlight the potential of thiol-bearing Zr-MOFs as efficient, cyclable adsorbents for heavy metal remediation applications.