Photodegradation of Binary Azo Dyes Using Core-Shell Fe<sub>3</sub>O<sub>4</sub>/SiO<sub>2</sub>/TiO<sub>2</sub> Nanospheres

Abstract

Photodegradation has emerged as an environmentally friendly method of decomposing harmful dyes in wastewater. In this study, core-shell Fe 3 O 4 /SiO 2 / TiO 2 nanospheres with magnetic cores were obtained from synthesised magnetic Fe 3 O 4 nanoparticles through the precipitation method, the surface of the magnetic Fe 3 O 4 nanoparticles was coated with a silica (SiO 2 ) layer by hydrolysis of tetramethoxysilane (TMOS) as a silica source, and finally, Fe 3 O 4 /SiO 2 nanospheres were coated with titanium (TiO 2 ) layer using tetrabutyltitanate (TBT) as a precursor through the sol-gel process. The morphology and structure of the prepared materials were characterised by X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), X-ray energy dispersive spectrometry (EDAX), Fourier transform infrared spectroscopy (FT-IR), and atomic force microscopy (AFM). The photocatalytic activities of the prepared core-shell nanospheres were studied using binary azo dyes, namely methyl orange (anionic dye, MO) and methylene blue (cationic dye, MB) in aqueous solution under UV light irradiation (365 nm), and UV-Vis spectrophotometer was utilised to monitor the amount of each dye in the mixture. It was found that 90.2% and 100% of binary MO and MB were removed for 5 h, respectively. The results revealed that the efficiency of the photocatalytic degradation of the core-shell nanospheres was not degreased after five runs that can be used as recyclable photocatalysts. The results show that the performance of the prepared core-shell nanospheres was better than that of commercial TiO 2 nanoparticles. Moreover, the magnetic separation properties of the core-shell Fe 3 O 4 /SiO 2 /TiO 2 nanospheres can enable the prepared materials to have wider application prospects.

Magnetite-impregnated biochar of parthenium hysterophorus for adsorption of Cr(VI) from tannery industrial wastewater

“…The precipitate of magnetite particles was then oven dried at a temperature of 60 °C overnight before being coated with biochar. Finally, the magnetic properties of the magnetite were checked using external magnetic substances (Alzahrani 2017;Frolova 2019;Moges et al 2022).…”

Lanthanum substituted Ni-Zn ferrite (Ni0.75Zn0.25Fe2O4) nanomaterial and its composite with rGO for degradation of binary dyes under visible light irradiation

“…Electrochemical impedance spectroscopy (EIS) is a versatile tool for measuring the conductivity, surface analysis, electron transfer and electron hole separation effectiveness [65]. The typical impedance spectra of NZF, NZLF-0.06 and NZLF@rGO modified CPEs are shown in figure 7(b).…”

Polymer Nanocomposites for Photocatalytic Degradation and Photoinduced Utilizations of Azo-Dyes

“…For instance, the TiO 2 that encapsulated ferrites could enhance the removal of azo-dye in textile effluents under both low-and high-energy lamps [36]. The Fe 3 O 4 /SiO 2 /TiO 2 nanospheres removed 90.2% and 100% of binary methyl orange and methylene blue in aqueous solution under UV light irradiation (365 nm) for 5 h [37]. In addition, TiO 2 based nanocomposites can be formed as hydrogel.…”