Arak University Colloid & Nanoscience Journal 2980-9215 3 4 2025 12 01 Silica sulfuric acid-modified ZrFe2O4 magnetic nanoparticles as an eco-friendly catalyst for the one-pot three-component synthesis of tetrahydrobenzo[b]pyran 742 752 733790 10.66224/CNJ.3.4.742 EN Maryam Borzooei Department of Chemistry, Faculty of Science, Ilam University, P.O. Box 69315516, Ilam, Iran Masoomeh Norouzi Department of Chemistry, Faculty of Science, Ilam University, P.O. Box 69315516, Ilam, Iran 0000-0002-0574-9358 Journal Article 2025 12 19 Magnetic nanoparticle-based supported catalysts are a promising class of stable and recyclable materials for green organic reactions. In this study, a novel sulfonic acid-functionalized zirconium ferrite nanostructure (ZrFe₂O₄@SiO₂–SO₃H) was successfully synthesized and characterized by fourier transform infrared (FT‐IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) image, X-ray atomic mapping spectrum, spectroscopy, energy-dispersive X-ray (EDX) analysis, brunauer, emmett, teller (BET)/ Langmuir plot and vibrating-sample magnetometry (VSM) analyses, confirming its well-designed core-shell structure. This magnetic nanocatalyst exhibits a high density of Brønsted acid sites along with easy magnetic separation, providing an efficient and reusable substrate for organic reactions. Its catalytic activity was investigated in the synthesis of tetrahydrobenzo[b]pyran derivatives, where the reactions proceeded in a short time with good to excellent yields (up to 98%) under mild conditions. Furthermore, the catalyst maintained its high performance over five consecutive cycles without significant loss of efficiency, indicating its remarkable chemical stability and magnetic recyclability. These results demonstrate the strong potential of ZrFe₂O₄@SiO₂–SO₃H as a robust and environmentally friendly nanocatalyst for high-yield organic syntheses and emphasize the importance of sulfonic acid-functionalized systems in the design of recyclable catalytic platforms. https://cnj.araku.ac.ir/article_733790_4b32a96bd5a67aad498804ec560fe3a0.pdf