Synthesis of stable mesoporous Zr-MOFs using pyrazine-containing ligand for efficient capture of Pb(II) in wastewater

By optimizing the reaction conditions, a zirconium-based adsorbent Zr-PzDC with pyrazine-2,5-dicarboxylic acid as the ligand was synthesized for the treatment of lead ions in an aqueous solution. SEM, EDS-Mapping, XRS and FT-IR characterization confirmed the synthesis of Zr-PzDC. Meanwhile, BET results show that Zr-PzDC is a typical mesoporous material. The analysis of the binding process of Zr-PzDC with Pb(II) in water shows that the adsorption kinetics conform to the pseudo-second-order model; The adsorption isotherm data fits well with the Langmuir model, and the maximum adsorption capacity of Pb(II) is 298.39 mg/g; The thermodynamic parameters show that the adsorption of Pb(II) in water is a spontaneous endothermic process. Combined with the XPS spectral results, physical adsorption is the main binding mode, and single-layer chemisorption is the limiting step in the adsorption process. The results of both static and dynamic column adsorption experiments show that Zr-PzDC can treat lead ions quickly and efficiently, and has excellent reusable performance, which makes Zr-PzDC have good application potential in treating lead-containing wastewater of the battery production process.