Theophylline-functionalized Fe3O4@SiO2 nanoparticles: synthesis, characterization and application as cadmium ion removal adsorbent

Ghahraman Afshar, Majid; Hamidavi, Hossein; Maleki, Abbas; BahramiPanah, Niloufar

doi:10.22034/ijche.2025.515329.1513

Theophylline-functionalized Fe3O4@SiO2 nanoparticles: synthesis, characterization and application as cadmium ion removal adsorbent

Articles in Press

Document Type : Original Article

Authors

Majid Ghahraman Afshar ¹

Hossein Hamidavi ²

Abbas Maleki ²

Niloufar BahramiPanah ³

¹ Assistant Professor, Chemistry and Process Research Department, Niroo Research Institute (NRI), Tehran, Iran

² Department of Chemistry, Payame Noor University, Tehran, Iran

³ Department of Chemistry, Payame Noor University (PNU), Tehran, Iran

10.22034/ijche.2025.515329.1513

Abstract

In this study, Fe3O4 nanoparticles are first synthesized using the co-precipitation method. Afterwards, the surface coating of iron oxide nanoparticles is performed to synthesize core-shell Fe3O4@SiO2 nanoparticles using the Stöber method by tetraethoxysilane as a silica source. After functionalization of Fe3O4@SiO2 nanoparticles with theophylline molecules, the synthesized nanoparticles are used as an effective adsorbent to remove cadmium ions from aqueous solutions. Particle size, morphology, magnetic properties, structural properties and surface functional groups are investigated using TEM, FE-SEM, VSM, BET, TGA, EDX, XRD and FT-IR. Finally, the effect of various amounts of adsorbent, contact time, pH and initial concentration of cadmium on the adsorption are investigated. The results of optimization of effective parameters at ambient temperature in the presence of 20 mg of adsorbent dose, pH 7 in 50 mL of solution with an initial concentration of 0.3 mmol/L for a contact time of 25 min resulted in 93.3 mg/g of cadmium adsorption. Moreover, the synthetic nanoadsorbent has the ability to be recovered and reused in successive adsorption-desorption cycles without serious reduction in functional activity.

Keywords

Fe3O4@SiO2 nanostructure

theophylline

surface adsorption

cadmium ion

magnetic separation

solid phase extraction

Subjects