Preparation and Characterization of Fe3O4/SiO2/TiO2 Composite for Methylene Blue Removal in Water

Abstract

The main problem with the slurry process is the difficulty in recovering the photocatalyst nanoparticle from water following purification. An alternative solution proposed the photocatalyst be immobilized on magnetic carriers, which would allow them to be recollected from the water suspension following treatment using an external magnetic field. Magnetically photocatalyst composites were prepared using simple heteroagglomeration by applying attractive electrostatic forces between the nanoparticles with an opposite surface charge. The Fe 3 O 4 /SiO 2 /TiO 2 photocatalysts were synthesized in an aqueous slurry solution containing Fe 3 O 4 /SiO 2 and TiO 2 nanoparticles under pH 5 conditions. Meanwhile, Fe 3 O 4 /SiO 2 was prepared by a simple procedure via a coprecipitation of iron(II) and iron(III) ion mixtures in ammonium hydroxide and was leached by sodium silicate. The synthesized samples were investigated to determine the phase structure, the magnetic properties, and the morphology of the composites by X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and transmission electron microscopy (TEM), respectively. The results indicated that the composites contained anatase and rutile phases and exhibited a superparamagnetic behavior. Fe 3 O 4 /SiO 2 particles, which were of the aggregation spherical form at 20 nm in size, were successfully attached onto the TiO 2 surface. The catalytic activity of Fe 3 O 4 /SiO 2 /TiO 2 composites was evaluated for the degradation of methylene blue under ultraviolet (UV) irradiation. The presence of SiO 2 as a barrier between Fe 3 O 4 and TiO 2 is not only improves the photocatalytic properties but also provides the ability to adsorb the properties on the composite. The Fe 3 O 4 /SiO 2 /TiO 2 (50% containing TiO 2 in composite) were able to eliminate 87.3% of methylene blue in water through the adsorption and photocatalytic processes. This result is slightly below pure TiO 2 , which is able to degrade 96% of methylene blue. The resulting Fe 3 O 4 /SiO 2 /TiO 2 composite exhibited an excellent ability to remove dye from water and it is easily recollected using a magnetic bar from the water. Therefore, they have high potency as an efficient and simple implementation for the dye effluent decolorization of textile waste in slurry reactor processes.

Experimental investigation of adsorption capacity of anthill in the removal of heavy metals from aqueous solution

“…However, the percentage of SiO 2 and Al 2 O 3 decreased after the adsorption process, as can also be seen in Exhibit . This implies that SiO 2 and Al 2 O 3 are identified adsorption sites in anthill, and their reduction in total composition after the adsorption process could also be attributed to the fact that the SiO 2 surface contained silanoh (OH group), which can interact with Pb 2+ and Zn 2+ (Fisli et al., ). A similar observation was reported for the adsorption of Pb 2+ , Cu 2+ , and Zn 2+ on soil (Lim & Lee, ).…”

“…According to Akinwekomi, Omotoyinbo, and Folorunso (), anthill sample contains metal oxides such as silica (SiO 2 ), alumina (SiO 2 ), iron oxide (Fe 2 O 3 ), and the like. However, some of these metal oxides in their pure or composite forms have been used as adsorbents for the removal of contaminants from wastewater (Eletta, Ajayi, Ogunleye, & Akpan, ; Fisli, Ridwan, Krisnandi, & Gunlazuardi, ). This is the main reason why anthill was chosen as an adsorbent for the removal of cations from aqueous solution for the present study.…”

Dyes Depollution of Water Using Porous TiO2-Based Photocatalysts

“…A mechanism for the OH radical generation and transport in these nanocomposites has been proposed. Interestingly, since powder materials are difficult to manipulate and to recover from liquid suspension, the introduction of iron oxide phase was realized in TiO2/SiO2 composites to allow easy magnetic removal of the catalyst from water after reaction (Fisli et al 2017).…”

Adsorption of Cationic Dye From Aqueous Solution Using Composite Chicken Eggshell - Anthill Clay: Optimization of Adsorbent Preparation Conditions

“…Thus, the result obtained indicates that not only CaO plays a significant role in the CEAC performance but also the other metal oxides (SiO 2 , Al 2 O 3 , ZrO 2 and Fe 2 O 3 ) contained in the optimal CEAC sample can determine the form of the molecular adsorption sites and their level of capacity. The presence of SiO 2 in the composite adsorbent plays a key role in the adsorption [29]. SiO 2 is known as an inorganic adsorbent and could adsorb either positive or negative contaminant depending on the pH of the solution [30].…”