Mesoporous silica containing ≡Si(CH2)3NHC(S)NHC2H5 functional groups in the surface layer

Area of Science:

• Materials Science
• Nanotechnology
• Environmental Chemistry

Background:

• Mesoporous silica materials like SBA-15 are valuable for adsorption applications.
• Functionalization of silica surfaces enhances selectivity and capacity for specific ions.
• Thiourea groups offer strong coordination sites for heavy metal ions.

Purpose of the Study:

• To develop a facile one-step synthesis of SBA-15 silica functionalized with thiourea groups.
• To characterize the structural and adsorption properties of the synthesized material.
• To evaluate its efficiency in removing silver(I) and mercury(II) ions from aqueous solutions.

Main Methods:

• One-step sol-gel synthesis using P123 template.
• Characterization using elemental analysis, TGA, FT-IR, XRD, TEM, and SEM.
• Nitrogen adsorption-desorption isotherms for surface area and pore size analysis.
• Batch adsorption experiments for Ag(I) and Hg(II) ions.

Main Results:

• Successfully synthesized mesoporous SBA-15 silica microspheres (~0.5 μm) with hexagonal lattice structure.
• Surface functionalization with thiourea groups confirmed by FT-IR and elemental analysis (1.25 mmol/g).
• High surface area (510 m²/g), pore volume (0.47 cm³/g), and pore diameter (4.3 nm) observed.
• Efficient and rapid sorption of Ag(I) and Hg(II) ions from acidified solutions achieved within 60 minutes.

Conclusions:

• The developed one-step method provides a scalable route to thiourea-functionalized SBA-15.
• The material exhibits excellent adsorption capacity and kinetics for silver and mercury ions.
• This functionalized silica is a promising adsorbent for heavy metal remediation.