فهرست نشریات علمی دسترسی آزاد ایران

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.