Synthesis, Characterization, and Photocatalytic Activity of Magnetically Separable Fe3O4@SiO2@ZnO-Ag Composite Photocatalyst

Magnetically separable Fe3O4, Fe3O4@SiO2, Fe3O4@SiO2@ZnO, and Fe3O4@SiO2@ZnO-Ag composites are synthesized using hydrothermal and wet chemistry methods. The samples obtained are characterized in terms of morphology, composition, optical, and magnetic properties using TEM, SEM-EDS, XRD, FTIR, VSM, XPS, and UV-vis, and the photodegradation of Acid Blue 161 dye under UV irradiation is investigated. As a result of SEM and TEM analyses, the diameters of Fe3O4, Fe3O4@SiO2, Fe3O4@SiO2@ZnO, and Fe3O4@SiO2@ZnO-Ag composites are determined as 210, 220, 230 and 235 nm, respectively. The magnetic properties of the samples are determined by VSM analysis. In VSM analyses, magnetization saturation values of Fe3O4, Fe3O4@SiO2, Fe3O4@SiO2@ZnO, and Fe3O4@SiO2@ZnO-Ag composites are determined as 81, 64, 41 and 20 emus x g(-1), respectively. In XRD analysis, the face-centered cubic structure of Fe3O4 particles and the hexagonal wurtzite structure of ZnO are determined and it is determined that they are compatible with standard diffraction cards. According to UV-Vis analysis, E-g values for Fe3O4, Fe3O4@SiO2, Fe3O4@SiO2@ZnO, and Fe3O4@SiO2@ZnO-Ag composites are found as 1.3, 1.68, 2.21, and 2.15 eV, respectively. Among the photocatalysts prepared, Fe3O4@SiO2@ZnO-Ag composite Acid Blue 161 shows superior removal and recyclability against photodegradation of the dyestuff.