Hydrotalcite-TiO2 magnetic iron oxide intercalated with the anionic surfactant dodecylsulfate in the photocatalytic degradation of methylene blue dye

Abstract

The new magnetic photocatalysts HT/TiO2/Fe and HT-DS/TiO2/Fe, modified with the anionic surfactant sodium dodecylsulfate (DS) were successfully synthesized in this work. Titanium dioxide (anatase) followed by iron oxide were deposited on the hydrotalcite support. Several catalyst samples were prepared with different amounts of titanium and iron. The photocatalysts were characterized by infrared and Raman spectroscopy, X-ray diffraction, scanning electron microscopy. Photocatalytic performance was analyzed by UV-visible radiation (filter cutoff, λ > 300 nm) of an aqueous solution (24 mg/L) of methylene blue (MB). The most efficient catalyst was obtained at an iron oxide:TiO2 molar ratio of 2:3. This catalyst showed high photocatalytic activity, removing 96% of the color and 61% of total organic carbon from the MB solution after 120 min. It was easily removed from solution after use because of its magnetic properties. The reuse of the HT-DS/TiO2/Fe23 catalyst was viable and the catalyst was structurally stable for at least four consecutive photocatalytic cycles.

Magnetic recyclable microcomposite silica-steel core with TiO2 nanocomposite shell photocatalysts for sustainable water purification

“…The measured high mass normalised dye degradation rates equal or exceed previously reported values for magnetically separable micron size photocatalytic particles tested under comparable reaction conditions. 33,34,36,37,40,42 Furthermore, the present magnetically separable photocatalysts are much cheaper, simpler to prepare, and readily scalable. All of these factors make them suitable for local manufacture and adoption in developing countries for sustainable water purification.…”

“…Previous examples for local production include: agglomerated TiO 2 coated sub-micron size iron oxide particles synthesised from ferric chloride (which is toxic), 32,33 handling and disposal of waste sulphuric acid) 34 , the combining TiO 2 particles and a magnetic component within an organic matrix (such as chitosan, 35 poly(methyl methacrylate), 36 or poly(vinyl pyrrolidone)) 37 to form micron-sized particles (these suffer from the organic host matrices themselves being vulnerable to photodegradation by the TiO 2 photocatalysts over extended periods of operation) 38,39 , and the utilisation of inorganic matrices, such as reduced graphene oxide, 40 SrFe 12 O 19 nanofibres, 41 or hydrotalcite clays, 42 ( which add significant costs).…”

Fe-Doped TiO2 Supported on HY Zeolite for Solar Photocatalytic Treatment of Dye Pollutants

“…It should be noted that the comparison has a relative meaning only, because of different testing conditions (concentration and nature of dye, catalyst amount, concentration, and the nature of dopant, experimental setup, etc.) and the type of TiO2 support [25,38,39,41,[62][63][64][65][66][67]. Nevertheless, if we look closely at the degradation of the dye pollutants, the present photocatalyst based on Fe-TiO2/HY attained very high decolorization percentages (>98%) at shorter times (60 min) and under milder conditions, avoiding the use of UV radiation or additional oxidizing reactants.…”

Enhanced photocatalytic activity of TiO2-impregnated with MgZnAl mixed oxides obtained from layered double hydroxides for phenol degradation

“…10) also resulted in the highest TOC reduction, reaching about 80% after 360 min. M a n u s c r i p t 20 Allied to this, the hydroxyl groups present in the LDH structure can react with the photogenerated hole in the VB of TiO 2 , and thereby promote the production of • OH [37,41,59].…”