Scholarlink

<p>This research introduces a highly mesoporous SiO<sub>2</sub>-chitin/MoO<sub>3</sub> nanocomposite aimed at the effective removal of Pb(II) and Cu(II) from water. The nanocomposite characterization using X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR) revealed changes in the surface binding energies particularly in the oxygen and nitrogen binding environment, suggesting the formation of new metal-oxygen and metal-nitrogen bonds post-adsorption. The composite surface demonstrated a negative zeta potential of -26.8 mV which promotes the adsorption of cationic Cu(II) and Pb(II) through Coulombic electrostatic interactions. This highlights the interplay mechanism between electrostatic attraction and surface complexation. The composite exhibited a high surface area of 266.95&#xa0;m²/g, a pore volume of 0.48&#xa0;cm³/g, and a well-defined mesoporous structure with an average pore diameter of 7.2&#xa0;nm. Scanning transmission electron microscopy (S-TEM) confirmed the uniform distribution of Si, O, and Mo, with some localized Mo clusters. X-ray diffraction (XRD) demonstrated well-crystallized MoO<sub>3</sub> nanoparticles within the amorphous SiO<sub>2</sub>-chitin matrix. Operational parameters such as pH, time, concentration, and dosage were optimized. The uptake results adhered to a pseudo-second-order kinetics model and Freundlich isotherm, confirming multilayer heterogeneous adsorption. The intraparticle diffusion study indicated the control of boundary layer diffusion and mass transfer resistance. Thermodynamic parameters showed endothermic adsorption with a greater affinity for Pb(II). Activation energy values were determined to be 15.36 and 20.48&#xa0;kJ/mol for Cu(II) and Pb(II), respectively, supporting chemisorption as the primary mechanism. Overall, SiO<sub>2</sub>-chitin/MoO<sub>3</sub> nanocomposite exhibited effective removal potential for Cu(II) and Pb(II) from aqueous solutions, while demonstrating high stability and reusability.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Mesoporous SiO2-chitin/MoO3 Nanocomposite: Synthesis, Surface Investigation, and Uptake Potential for Pb(II) and Cu(II)

  • 期刊论文

  • 发表日期：

    2025年4月21日

查看全文
  • Hany Fathy Heiba,
  • Asia A. Taha,
  • Alaa R. Mostafa,
  • Abeer Elsaharty,
  • Manal G. Mahmoud,
  • Laila A. Mohamed

摘要

This research introduces a highly mesoporous SiO2-chitin/MoO3 nanocomposite aimed at the effective removal of Pb(II) and Cu(II) from water. The nanocomposite characterization using X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR) revealed changes in the surface binding energies particularly in the oxygen and nitrogen binding environment, suggesting the formation of new metal-oxygen and metal-nitrogen bonds post-adsorption. The composite surface demonstrated a negative zeta potential of -26.8 mV which promotes the adsorption of cationic Cu(II) and Pb(II) through Coulombic electrostatic interactions. This highlights the interplay mechanism between electrostatic attraction and surface complexation. The composite exhibited a high surface area of 266.95 m²/g, a pore volume of 0.48 cm³/g, and a well-defined mesoporous structure with an average pore diameter of 7.2 nm. Scanning transmission electron microscopy (S-TEM) confirmed the uniform distribution of Si, O, and Mo, with some localized Mo clusters. X-ray diffraction (XRD) demonstrated well-crystallized MoO3 nanoparticles within the amorphous SiO2-chitin matrix. Operational parameters such as pH, time, concentration, and dosage were optimized. The uptake results adhered to a pseudo-second-order kinetics model and Freundlich isotherm, confirming multilayer heterogeneous adsorption. The intraparticle diffusion study indicated the control of boundary layer diffusion and mass transfer resistance. Thermodynamic parameters showed endothermic adsorption with a greater affinity for Pb(II). Activation energy values were determined to be 15.36 and 20.48 kJ/mol for Cu(II) and Pb(II), respectively, supporting chemisorption as the primary mechanism. Overall, SiO2-chitin/MoO3 nanocomposite exhibited effective removal potential for Cu(II) and Pb(II) from aqueous solutions, while demonstrating high stability and reusability.