Green synthesis of a novel magnetic Fe3O4@SiO2/TiO2@WO3 nanocomposite for methylene blue removal under UV and visible light irradiations

This article investigates the photocatalytic performance of a nanocomposite, consisting of two nanocore-shell-nanoparticles, kind of Fe3O4@SiO2 and WO3@TiO2, to degrade methylene blue (MB). The materials were prepared using environmentally-friendly reagents through energy efficient methods, without consumption of any dangerous solvents. The characterizations were conducted by x-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, Brunauer-Emmett-Teller, energy dispersive x-ray spectroscopy, elemental mapping and alternating gradient force magnetometer. In this nanocomposite, TiO2 is the main component, with the aim of producing sufficient reactive radicals to degrade MB; however, WO3 is helpful to reach the better performance of Fe3O4@SiO2 and WO3@TiO2 for MB degradation. SiO2 increases the specific surface area and Fe3O4 makes the nanocomposite controllable by an external magnetic field. To reach the best degradation recovery, the ratio of TiO2@WO3 to Fe3O4@SiO2 (10:1.4), pH (?6), nanocatalyst load (6.0 x 10(-2) g) and radiation time (60 min) were optimized. Reusability of four times and durability of six months were recorded. To better understand the MB degradation by Fe3O4@SiO2/TiO2@WO3, a suggested mechanism was investigated in detail, confirming that superoxide is the main specie to degrade MB. A real sample of textile effluent was applied successfully.

Automated summary

This article investigates the photocatalytic performance of a nanocomposite, consisting of two nanocore-shell-nanoparticles, Fe3O4@SiO2 and WO3@TiO2, for degrading methylene blue (MB). The materials were prepared using environmentally-friendly reagents and energy efficient methods. The characterization of the materials was conducted using various techniques. The optimal conditions for methylene blue degradation were determined, and the nanocomposite showed good reusability and durability.