Fe3O4@SiO2@WO3 Multifunctional Composite Photocatalyst with Magnetic Core and Dual Shells

WO3 has attracted great attention in the field of catalysts due to its excellent photocatalytic performance. However, the difficulty in recycling and low reuse percentage of nano WO3 limit its application. This paper used the hydrothermal method to prepare an Fe3O4@SiO2@WO3 core–shell nanocatalyst. Its composition and structure were characterized by various techniques including XRD, FT-IR, and Raman analyses, which confirmed the successful preparation of a core–shell-structured catalyst with a strong response to an external magnetic field. In the degradation experiment of rhodamine B solution (RhB), the composite catalyst with a WO3 doping amount of 0.8 g and catalyst dosage amount of 30 mg had the best catalytic degradation effect on 10 ppm RhB, with a degradation efficiency of 99.80%. Due to its high transparency and ion conductivity, SiO2 did not affect the performance of the composite catalyst, but could effectively reduce the corrosion of WO3 by the reaction solution. The presence of a SiO2 interlayer prevented any deterioration in the catalytic efficiency of WO3 nanocrystal shells and the chemical and thermal stability of Fe3O4 nuclei. By applying an external magnetic field, this nanocatalyst can be easily recovered from the solution. These features not only maximize the value of this new material, but also provide sustainable solutions for environmental protection, energy crises, and health issues.