Sharif University of Technology Scientia Iranica 1026-3098 32 13 2025 08 01 The effect of silica mass ratio on pore structure and magnetic characteristics of Fe3O4@SiO2 core-shell nanoparticles 24197 10.24200/sci.2024.61855.7524 EN Munasir Nasir Department of Physics, Faculty of Mathematics and Sciences, Universitas Negeri Surabaya (Unesa), Surabaya-Indonesia. Lydia Rohmawati Department of Physics, Faculty of Mathematics and Sciences, Universitas Negeri Surabaya (Unesa), Surabaya-Indonesia. Nuhaa Faaizatunnisa Department of Chemistry, FSAD, Institut Teknologi Sepuluh Nopember (ITS), Surabaya, Indonesia. Ahmad Taufiq Department of Physics, Universitas Negeri Malang (UM), Malang, Indonesia. Journal Article 2023 02 06 The fabrication of Fe3O4@SiO2 core-shell was prepared from natural iron sand as Fe3O4 core resource and in situ SiO2-coating method. Fe3O4@SiO2 was synthesized via an ultrasonic route with various ratios of Tetra-Ethyl Ortho-Silicate (TEOS) to evaluate the morphological, pore structure, and magnetic properties of the core-shell. X-Ray Diffraction (XRD) and Fourier Transform Infra-Red (FTIR) were used to characterize the prepared Fe3O4 and Fe3O4@SiO2. Scanning Electron Microscope (SEM) was used to analyze the effect of TEOS on the particle size, and Transmission Electron Microscopy (TEM) was used to observe the morphology of core-shell and shell thickness. The Brunauer-Emmett-Teller (BET) data revealed that Fe3O4@SiO2 (65) exhibited a larger pore diameter of 88.17 nm and eight-times higher BET surface area (80.23 m2/g) than Fe3O4@SiO2 (55) and Fe3O4@SiO2 (45) (27.69 nm; 10.5 m2/g). The Vibrating Sample Magnetometer (VSM) data indicated that increased TEOS addition on Fe3O4@SiO2 caused a decrease in the magnetization value but still gave good magnetic properties from 95.32 emu/g for Fe3O4@SiO2 (45) to 17.02 emu/g for Fe3O4@SiO2 (65). The study found that the higher SiO2 content reduced the agglomeration of the Fe3O4 core, as indicated by no hysteresis loop on the gas of Nitrogen (N2) adsorption-desorption curve of Fe3O4@SiO2 (65), resulting in core-shell material with better properties in higher specific surface area, average pore size and volume for further application. https://scientiairanica.sharif.edu/article_24197_3841dc0410fc9e17a55193410354ab17.pdf