Synthesis and characterization of magnetic core-shell nanoparticles decorated with theophylline molecules as an effective adsorbent for zinc removal from aqueous samples

Subject Areas : journal of New Materials

Mohsen Esmaeilpour ¹ , Majid Ghahraman Afshar ^{2 *} , MIlad Kazemnejadi ³ , Hossein Ghaseminejad ⁴

1 - Chemistry and Process Research Department, Niroo Research Institute (NRI), Tehran, Iran
2 - Polymer Chemistry Lab, Chemistry Department, Faculty of Sciences, Golestan University, Gorgan, Iran
3 - Polymer Chemistry Lab, Chemistry Department, Faculty of Sciences, Golestan University, Gorgan, Iran
4 - Chemistry and Process Research Department, Niroo Research Institute (NRI), Tehran, Iran

Received: 2025-04-24 Accepted : 2025-06-09 Published : 2025-06-09

Keywords: استخراج فاز جامد, Fe3O4@SiO2, تئوفیلین, حذف مؤثر, یون¬های روی, هسته- پوسته,

Abstract :

Introduction: In the present study, Fe₃O₄ nanoparticles were synthesized using the co-precipitation method. Subsequently, due to the high surface activity of Fe₃O₄ nanoparticles and their solubility in acidic media, the surface of the nanoparticles was coated with a silica layer and core-shell particles of Fe₃O₄@SiO₂ were obtained. Subsequently, the core-shell nanoparticles were functionalized with organic compounds and theophylline molecules. 

Methods: The characteristics, size and morphology of the synthesized nanoparticles were determined using Fourier transform infrared spectroscopy, X-ray diffraction, nitrogen gas adsorption-desorption, vibrating sample magnetometer, thermal weighing analysis, scanning electron microscopy, transmission electron microscopy and particle size distribution. Subsequently, the synthesized nanoparticles were used as an adsorbent for the extraction of zinc ions from aqueous solutions and the parameters affecting the adsorption of the target ion were optimized.

Findings: The maximum adsorption capacity of the nanoadsorbent was achieved using 60 ml of zinc solution with an initial concentration of 0.5 mmol/L, 21 mg of nanoadsorbent at pH 7 and a contact time of 25 minutes at ambient temperature. In addition, the synthetic nanoadsorbent has the ability to be recycled and reused in consecutive adsorption-desorption cycles for 7 times without serious reduction in adsorption activity.

Conclusion: Based on the results and considering the ideal properties of the synthetic nanoadsorbent such as high adsorption capacity and the ability to recover and reuse, the use of this nanoadsorbent in real water and wastewater samples for the removal of heavy metal ions is highly recommended.

References:

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