Comparison of the structural and photo-catalytic properties of nanostructured Fe3O4/TiO2 core-shell composites synthesized by ultrasonic and Stöber methods

Abstract

In the present research, Fe3O4/TiO2 magnetic photo-catalytic nanocomposites with a core/shell structure were successfully synthesized using two techniques of ultrasonic and St?ber. In this way, iron oxide (II, III) nanoparticles as soft magnetic cores of this composite were prepared by utilizing a chemical method assisted by ultrasound with a Fe+3/Fe+2 molar ratio of 1.5 under the nitrogen atmosphere. Thereafter, titanium oxide coating was performed on Fe3O4 nanoparticles by using tetrabutyl orthotitanate (TBOT) and titanium isopropoxide (TTIP) precursors. The resultant nanostructures were characterized by means of X-ray powder diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, energy dispersive X-ray (EDX) analysis, vibrating sample magnetometer (VSM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Through findings obtained from TEM examinations, the formation of core/shell nanostructure was confirmed in the prepared Fe3O4/TiO2 composites. Analysis of magnetic properties revealed that titanium oxide coating on iron oxide nanoparticles reduces saturation magnetization (Ms). The values of saturation magnetization for Fe3O4 powder and Fe3O4/TiO2 nanocomposite powders achieved via ultrasonic and St?ber methods were 60, 23 and 9 emu/g, respectively. Photo-catalytic properties of Fe3O4/TiO2 nanostructures were evaluated by the use of methylene blue dye under UV light. Results indicated that Fe3O4/TiO2 composite obtained by the St?ber method has a better photo-catalytic property as well as a decreased but acceptable magnetic separation. Degradation of methylene blue dye in the presence of photo-catalytic powder prepared by ultrasonic and St?ber procedures was 61 and 69 %, respectively, within 90 minutes of UV light exposure.

Synthesis, characterization and photocatalytic efficiency of Fe3O4/SiO2/TiO2, SrFe12O19/SiO2/TiO2 and Fe3O4/SiO2/ZnO core/shell/shell nanostructures

“…In this regard, the photocatalytic powders were added to the methylene blue solution (50 mg/l) [18,49] and stirred for 0.5 h in the dark. This time indicates the approximate time required for the establishment of adsorption-desorption equilibrium in dark conditions [50]. Then it was exposed to the UV light (lamp of 20 W power).…”

Preparation of SrFe12O19/SiO2/TiO2 Photocatalysts and Degradation of Methylene Blue and Petroleum Wastewater

“…However, the challenging recovery of nano-TiO 2 prevent it from being widely used in industry. [9][10][11][12][13] Magnetic photocatalysts are composite materials that include semiconductors that manufacture extremely active oxidants beneath photoexcitation and magnetic materials with recycling capability. The incorporation of magnetic components into TiO 2 nanoparticle-based catalysts has received considerable attention in recent years.…”

“…Nano‐TiO 2 is one of the most extensively researched photocatalysts because of its benefits such as low cost, strong chemical stability, high photocatalytic activity, nontoxicity, and broad application. However, the challenging recovery of nano‐TiO 2 prevent it from being widely used in industry [9–13] …”

TiO2 nanotubes film/FTO glass interface: Thermal treatment effects

“…As a rule, the photoanode is a titanium oxide (TiO 2 ) based film deposited on a transparent substrate. TiO 2 is an n-type semiconductor that has many different applications: in solar cells [7], gas sensors [8], lithium batteries [9], for photocatalysis [10], improving mechanical performance of ceramics [11] and etc. The most used form of TiO 2 is of nanoparticles, but the drawback of this morphology is the randomization of the particle network with agglomeration and interholes.…”