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 , MIlad Kazemnejadi ² , Majid Ghahraman Afshar ^{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 - Chemistry and Process Research Department, Niroo Research Institute (NRI), Tehran, 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:

1Fang L, Xiao X, Kang R, Ren Z, Yu H, Pavlostathis SG, et al. Highly selective adsorption of antimonite by novel imprinted polymer with microdomain confinement effect. Journal of Chemical & Engineering Data. 2018;63(5):1513-23.
.2Kong D, Wang N, Qiao N, Wang Q, Wang Z, Zhou Z, et al. Facile preparation of ion-imprinted chitosan microspheres enwrapping Fe3O4 and graphene oxide by inverse suspension cross-linking for highly selective removal of copper (II). ACS Sustainable Chemistry & Engineering. 2017;5(8):7401-9.
.3Yang S, Qian J, Kuang L, Hua D. Ion-imprinted mesoporous silica for selective removal of uranium from highly acidic and radioactive effluent. ACS applied materials & interfaces. 2017;9(34):29337-44.
.4Li H, Jia Y, Chen Y, Ye Q, Xian L, Qian J. Amino-functionalized Yolk-shell Magnetic Silica Nanoparticles for the Selective Removal of Heavy Metal Ions. Microporous and Mesoporous Materials. 2025:113535.
.5Asgharinezhad AA, Esmaeilpour M, Afshar MG. Synthesis of magnetic Fe3O4@ SiO2 nanoparticles decorated with polyvinyl alcohol for Cu (II) and Cd (II) ions removal from aqueous solution. Chemical Papers. 2024;78(6):3799-814.
.6Li J, Wang S, Zhu Q, Xu D, Wang Y, Zhang X, et al. L-arginine-enhanced PEI-based polyamide Nanofiltration membranes for efficient heavy metal ion removal. Desalination. 2025:118680.
.7Ghahraman Afshar M, Esmaeilpour M, Kazemnejadi M, Yousefpour A. Fe3O4@ SiO2 nanoparticles functionalized with glucosamine molecules as an effective and recyclable magnetic adsorbent to remove Zn2+. Iranian Chemical Engineering Journal. 2024.
.8Ghahraman Afshar M, Esmaeilpour M, Larimi A, Asgharinezhad A. Core-shell Nanoparticles Functionalized with Polyvinyl Alcohol Molecules: Effective Magnetic Nanoadsorbent for Removing Zn2+ Ions from Aqueous Solutions. Iranian Chemical Engineering Journal. 2024.
.9He J, Chen JP. A comprehensive review on biosorption of heavy metals by algal biomass: materials, performances, chemistry, and modeling simulation tools. Bioresource technology. 2014;160:67-78.
.10Yu K, Yang L, Zhang S, Zhang N. Nanocellulose-based aerogels for the adsorption and removal of heavy-metal ions from wastewater: A review. Materials Today Communications. 2025:111744.
.11Esmaeilpour M, Ghahraman Afshar M, Noroozi Tisseh Z, Ghahremanzadeh R. Evaluation of the Performance of MnFe2O4 Nanoparticles Functionalized with N-Phosphonomethyl Amino Diacetic Acid as an Effective Magnetic Nanosorbent for the Removal of Ni (II), Pb (II), V (V) Ions from Aqueous Solutions. Iranian Chemical Engineering Journal. 2023;22(130):90-104.
.12Yang J, Zhang X, Chen M, Huang Y, Tian B, Wang N, et al. Versatile hydrogen-bonded organic framework (HOF) platform for simultaneous detection and efficient removal of heavy metal ions. Journal of Environmental Chemical Engineering. 2022;10(6):108983.
.13Gong W, Zheng K, Zhang C, Liu L, Shan Y, Yao J. Simultaneous and efficient removal of heavy metal ions and organophosphorus by amino-functionalized cellulose from complex aqueous media. Journal of Cleaner Production. 2022;367:133040.
.14Inaloo ID, Majnooni S, Eslahi H, Esmaeilpour M. N-Arylation of (hetero) arylamines using aryl sulfamates and carbamates via C–O bond activation enabled by a reusable and durable nickel (0) catalyst. New Journal of Chemistry. 2020;44(31):13266-78.
.15Sardarian AR, Eslahi H, Esmaeilpour M. Green, cost‐effective and efficient procedure for Heck and Sonogashira coupling reactions using palladium nanoparticles supported on functionalized Fe3O4@ SiO2 by polyvinyl alcohol as a highly active, durable and reusable catalyst. Applied Organometallic Chemistry. 2019;33(7):e4856.
.16Zhou T, Zhan X, Diao K, Du J, Xu Y, Du J, et al. RGO loaded Fe3O4 strategy to construct high toughness PAM hydrogel for electromagnetic shielding. Progress in Organic Coatings. 2024;196:108750.
.17Khafoor AA, Karim AS, Sajadi SM. The effect of Alanine and Morine functional agents on antimicrobial potential of green synthesized CuO@ Fe3O4@ Xanthan NCs using Pterocephalus nestorianus extract. Results in Chemistry. 2024;9:101625.
.18Esmaeilpour M, Zahmatkesh S, Fahimi N, Nosratabadi M. Palladium nanoparticles immobilized on EDTA‐modified Fe3O4@ SiO2 nanospheres as an efficient and magnetically separable catalyst for Suzuki and Sonogashira cross‐coupling reactions. Applied Organometallic Chemistry. 2018;32(4):e4302.
.19Fang H, Meng F, Chen G, Wang L, Zhang S, Yan J, et al. Sandwich-structured Fe3O4/graphene hybrid film for high-performance lithium-ion batteries. International Journal of Electrochemical Science. 2019;14(8):7937-46.
.20Esmaeilpour M, Javidi J. Fe3O4@ SiO2‐imid‐PMAn Magnetic Porous Nanosphere as Reusable Catalyst for Synthesis of Polysubstituted Quinolines under Solvent‐free Conditions. Journal of the Chinese Chemical Society. 2015;62(4):328-34.
.21Wang L, Neoh KG, Kang E-T, Shuter B. Multifunctional polyglycerol-grafted Fe3O4@ SiO2 nanoparticles for targeting ovarian cancer cells. Biomaterials. 2011;32(8):2166-73.
.22Sardarian A, Kazemnejadi M, Esmaeilpour M. Functionalization of superparamagnetic Fe3O4@ SiO2 nanoparticles with a Cu (II) binuclear Schiff base complex as an efficient and reusable nanomagnetic catalyst for N‐arylation of α‐amino acids and nitrogen‐containing heterocycles with aryl halides. Applied Organometallic Chemistry. 2021;35(1):e6051.
.23Zhao L, Chi Y, Yuan Q, Li N, Yan W, Li X. Phosphotungstic acid anchored to amino–functionalized core–shell magnetic mesoporous silica microspheres: A magnetically recoverable nanocomposite with enhanced photocatalytic activity. Journal of colloid and interface science. 2013;390(1):70-7.
.24Sardarian AR, Abbasi F, Esmaeilpour M. Fe3O4@ Zein nanocomposites decorated with copper (II) as an efficient, durable, and biocompatible reusable catalyst for click synthesis of novel fluorescent 1, 4-disubstituted-1, 2, 3-triazoles in water. Sustainable Chemistry and Pharmacy. 2023;36:101256.
.25Esmaeilpour M, Ghahraman Afshar M. Magnetic Nanoadsorbent: Preparation, characterization, and Adsorption Properties for Removal of Copper (II) from Aqueous Solutions. Applied Chemistry Today. 2023;18(69):11-20.
.26Dindarloo Inaloo I, Majnooni S, Eslahi H, Esmaeilpour M. Nickel (II) nanoparticles immobilized on EDTA-modified Fe3O4@ SiO2 nanospheres as efficient and recyclable catalysts for ligand-free Suzuki–Miyaura coupling of aryl carbamates and sulfamates. ACS omega. 2020;5(13):7406-17.
.27Dindarloo Inaloo I, Majnooni S, Eslahi H, Esmaeilpour M. Air‐Stable Fe3O4@ SiO2‐EDTA‐Ni (0) as an Efficient Recyclable Magnetic Nanocatalyst for Effective Suzuki‐Miyaura and Heck Cross‐Coupling via Aryl Sulfamates and Carbamates. Applied Organometallic Chemistry. 2020;34(8):e5662.
.28Mahmed N, Friman M, Hannula S-P. Phase transformation of iron oxide–silica coreshell structure during differential scanning calorimetry and pulsed electric current sintering processes: A comparison. Materials Letters. 2012;85:18-20.
.29Sardarian AR, Mohammadi F, Esmaeilpour M. Dendrimer-encapsulated copper (II) immobilized on Fe 3 O 4@ SiO 2 NPs: a robust recoverable catalyst for click synthesis of 1, 2, 3-triazole derivatives in water under mild conditions. Research on Chemical Intermediates. 2019;45:1437-56.
.30Asgharinezhad AA, Esmaeilpour M, Siavoshani AY. Extraction and preconcentration of Ni (ii), Pb (ii), and Cd (ii) ions using a nanocomposite of the type Fe 3 O 4@ SiO 2@ polypyrrole-polyaniline. RSC advances. 2022;12(30):19108-14.
.31Zhang F, Lan J, Zhao Z, Yang Y, Tan R, Song W. Removal of heavy metal ions from aqueous solution using Fe3O4–SiO2-poly (1, 2-diaminobenzene) core–shell sub-micron particles. Journal of colloid and interface science. 2012;387(1):205-12.
.32Ebrahimzadeh H, Asgharinezhad AA, Tavassoli N, Sadeghi O, Amini MM, Kamarei F. Separation and spectrophotometric determination of very low levels of Cr (VI) in water samples by novel pyridine-functionalized mesoporous silica. International Journal of Environmental Analytical Chemistry. 2012;92(4):509-21.
.33Jalilian N, Ebrahimzadeh H, Asgharinezhad AA, Molaei K. Extraction and determination of trace amounts of gold (III), palladium (II), platinum (II) and silver (I) with the aid of a magnetic nanosorbent made from Fe 3 O 4-decorated and silica-coated graphene oxide modified with a polypyrrole-polythiophene copolymer. Microchimica acta. 2017;184:2191-200.
.34Soni S, Bajpai P, Mittal J, Arora C. Utilisation of cobalt doped Iron based MOF for enhanced removal and recovery of methylene blue dye from waste water. Journal of Molecular Liquids. 2020;314:113642.
.35Mubarak N, Alicia R, Abdullah E, Sahu J, Haslija AA, Tan J. Statistical optimization and kinetic studies on removal of Zn2+ using functionalized carbon nanotubes and magnetic biochar. Journal of Environmental Chemical Engineering. 2013;1(3):486-95.
.36Smičiklas I, Onjia A, Raičević S, Janaćković Đ, Mitrić M. Factors influencing the removal of divalent cations by hydroxyapatite. Journal of hazardous materials. 2008;152(2):876-84.
.37Abbas A, Al-Amer AM, Laoui T, Al-Marri MJ, Nasser MS, Khraisheh M, et al. Heavy metal removal from aqueous solution by advanced carbon nanotubes: critical review of adsorption applications. Separation and Purification Technology. 2016;157:141-61.
.38Abuhatab S, El-Qanni A, Al-Qalaq H, Hmoudah M, Al-Zerei W. Effective adsorptive removal of Zn2+, Cu2+, and Cr3+ heavy metals from aqueous solutions using silica-based embedded with NiO and MgO nanoparticles. Journal of Environmental Management. 2020;268:110713.
.39Lin S-H, Juang R-S. Heavy metal removal from water by sorption using surfactant-modified montmorillonite. Journal of hazardous materials. 2002;92(3):315-26.
.40Xiang B, Fan W, Yi X, Wang Z, Gao F, Li Y, et al. Dithiocarbamate-modified starch derivatives with high heavy metal adsorption performance. Carbohydrate polymers. 2016;136:30-7.
.41Wang R-y, Zhang W, Zhang L-y, Hua T, Tang G, Peng X-q, et al. Adsorption characteristics of Cu (II) and Zn (II) by nano-alumina material synthesized by the sol-gel method in batch mode. Environmental Science and Pollution Research. 2019;26:1595-605.
.42Erdem E, Karapinar N, Donat R. The removal of heavy metal cations by natural zeolites. Journal of colloid and interface science. 2004;280(2):309-14.
.43Sheikhhosseini A, Shirvani M, Shariatmadari H. Competitive sorption of nickel, cadmium, zinc and copper on palygorskite and sepiolite silicate clay minerals. Geoderma. 2013;192:249-53.
.44Adamczuk A, Kołodyńska D. Equilibrium, thermodynamic and kinetic studies on removal of chromium, copper, zinc and arsenic from aqueous solutions onto fly ash coated by chitosan. Chemical Engineering Journal. 2015;274:200-12.
.45Su Q, Pan B, Wan S, Zhang W, Lv L. Use of hydrous manganese dioxide as a potential sorbent for selective removal of lead, cadmium, and zinc ions from water. Journal of colloid and interface science. 2010;349(2):607-12.
.46Charpentier TV, Neville A, Lanigan JL, Barker R, Smith MJ, Richardson T. Preparation of magnetic carboxymethylchitosan nanoparticles for adsorption of heavy metal ions. ACS omega. 2016;1(1):77-83.
.47Sargin I, Arslan G, Kaya M. Production of magnetic chitinous microcages from ephippia of zooplankton Daphnia longispina and heavy metal removal studies. Carbohydrate polymers. 2019;207:200-10.
.48Ge F, Li M-M, Ye H, Zhao B-X. Effective removal of heavy metal ions Cd2+, Zn2+, Pb2+, Cu2+ from aqueous solution by polymer-modified magnetic nanoparticles. Journal of hazardous materials. 2012;211:366-72.