<p>In this work, two new hybrid materials, <b>MP</b><sub><b>1</b></sub> and <b>MP</b><sub><b>2</b></sub>, were synthesized by modifying the mesoporous silica <b>MCM-41</b> with 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin as well as 5,10,15,20-tetra(pyridin-4-yl)porphyrin, respectively. The successful modification was consistently confirmed through multiple characterization techniques. The adsorption performance of these hybrid systems for Cd(II), Cu(II), and Pb(II) ions was thoroughly investigated using different isotherm and kinetic models to understand the adsorption mechanism. Both materials exhibited significant affinity for Pb(II) ions, with maximum adsorption capacities of 265.70&#xa0;mg/g for <b>MP</b><sub><b>1</b></sub> and 77.69&#xa0;mg/g for <b>MP</b><sub><b>2</b></sub>, surpassing many previously reported systems. The adsorption process was remarkably fast, reaching 65% of maximum uptake within 10&#xa0;min and complete removal from solution within 45&#xa0;min. Selectivity studies showed that these adsorbents efficiently removed 70% of Pb(II) ions even in the presence of Cd(II) and Cu(II) ions at similar concentrations. Furthermore, both adsorbents demonstrated excellent reusability, maintaining high efficiency over five consecutive cycles with minimal capacity loss. Most importantly, their performance was validated using real river water samples from the Marchica River, achieving up to 89% Pb(II) removal at trace concentrations. The adsorption equilibrium and kinetic data fitted well to the Sips, Langmuir, and pseudo-second-order models (<i>R</i><sup>2</sup> &gt; 0.99), indicating a homogeneous monolayer adsorption mechanism dominated by chemisorption. Thermodynamic parameters (ΔG &lt; 0, ΔH &gt; 0) showed that the adsorption was endothermic, spontaneous, and became more favorable at higher temperatures. These results highlight the strong potential of porphyrin conjugation with mesoporous silica <b>MCM-41</b> to develop efficient, selective, and cost-effective adsorbents for toxic metal ions removal in practical applications.</p> Graphical Abstract <p></p>

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Highly selective and reusable porphyrin-functionalized MCM-41 for efficient lead(II) removal from contaminated water: comprehensive adsorption study and real-water validation

  • Youssef Draoui,
  • Smaail Radi,
  • Mengmeng Wang,
  • Amal El Mahdaoui,
  • Chahrazad El Abiad,
  • Aurelian Rotaru,
  • Yann Garcia,
  • M. Amparo F. Faustino,
  • M. Graça P. M. S. Neves,
  • Nuno M. M. Moura

摘要

In this work, two new hybrid materials, MP1 and MP2, were synthesized by modifying the mesoporous silica MCM-41 with 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin as well as 5,10,15,20-tetra(pyridin-4-yl)porphyrin, respectively. The successful modification was consistently confirmed through multiple characterization techniques. The adsorption performance of these hybrid systems for Cd(II), Cu(II), and Pb(II) ions was thoroughly investigated using different isotherm and kinetic models to understand the adsorption mechanism. Both materials exhibited significant affinity for Pb(II) ions, with maximum adsorption capacities of 265.70 mg/g for MP1 and 77.69 mg/g for MP2, surpassing many previously reported systems. The adsorption process was remarkably fast, reaching 65% of maximum uptake within 10 min and complete removal from solution within 45 min. Selectivity studies showed that these adsorbents efficiently removed 70% of Pb(II) ions even in the presence of Cd(II) and Cu(II) ions at similar concentrations. Furthermore, both adsorbents demonstrated excellent reusability, maintaining high efficiency over five consecutive cycles with minimal capacity loss. Most importantly, their performance was validated using real river water samples from the Marchica River, achieving up to 89% Pb(II) removal at trace concentrations. The adsorption equilibrium and kinetic data fitted well to the Sips, Langmuir, and pseudo-second-order models (R2 > 0.99), indicating a homogeneous monolayer adsorption mechanism dominated by chemisorption. Thermodynamic parameters (ΔG < 0, ΔH > 0) showed that the adsorption was endothermic, spontaneous, and became more favorable at higher temperatures. These results highlight the strong potential of porphyrin conjugation with mesoporous silica MCM-41 to develop efficient, selective, and cost-effective adsorbents for toxic metal ions removal in practical applications.

Graphical Abstract