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

Abstract

Highlight► The catalysts composite TiO 2 /MgZnAl-5, was more efficient than TiO 2 P25.► The effects of different molar ratios zinc on the photocatalysts were investigated.► Synergistic effect between constituents of TiO 2 /MgZnAl-5 increases the photocatalysis.► TiO 2 /MgZnAl-5 exhibited the adsorption of light displacing the greater wavelength.► The catalyst composite TiO 2 /MgZnAl-5 can be reused for five consecutive cycles. AbstractPage 2 of 34 A c c e p t e d M a n u s c r i p t 2 A series of TiO 2 /MgZnAl photocatalysts, were successfully synthesized from ternary (Mg, Zn and Al) layered double hydroxides impregnated with TiO 2 nanoparticles by the co-precipitation method at variable pH with different Zn 2+ /Mg 2+ molar ratios . The composite photocatalysts were calcined at 500 °C resulting in the incorporation of oxide zinc, in the calcined MgZnAl LDH structure. Synergistic effect between ZnO and TiO 2 lead to significant enhancement of TiO 2 /MgZnAl photocatalytic activity. Composite photocatalysts were characterized by ICP-MS, N 2 adsorption/desorption, XRD, SEM, EDS, IR and UV-Vis DRS. Phenol in aqueous solution (50 mg/L) was used as a model compound for evoluation of UV-Vis (filter cutoff for λ > 300 nm) photocatalytic activity . The most efficient phocatalyst composite was obtained at a 5% Zn 2+ /Mg 2+ molar ratio , in the catalyst identified as TiO 2 /MgZnAl-5. This composite catalyst had high photocatalytic activity, completely destroying phenol and removing 80% of total organic carbon in solution after 360 min.The TiO 2 /MgZnAl-5 catalyst remained relatively stable, presenting a 15% decrease in phenol degradation efficiency after five consecutive photocatalytic cycles.

Synthesis, Characterization and Enhanced Photocatalytic Activity of Iron Oxide/Carbon Nanotube/Ag-doped TiO2 Nanocomposites

“…The monitoring of the remaining phenol concentrations was carried out by high performance liquid chromatography (HPLC) using a 1260 Infinity system with a linear photodiode array detector (DAD) (Agilent Technologies). The chromatographic conditions used for quantification of phenol by HPLC-DAD are described by Almeida et al 25 Photolysis was evaluated under the same conditions without the presence of the catalyst and only UV-Vis light. All studies were performed in triplicate.…”

Highly efficient Ru/TiO2 -NiAl mixed oxide catalysts for CO selective methanation in hydrogen-rich gas

“…In this regard, TiO 2 attracted our attention as it has been reported to be effective in CO‐SMET . Until now, TiO 2 ‐MMO coupled composites obtained from TiO 2 ‐LDH precursors have shown promising applications in photodegradation and solar cells . However, there are few reports on the application of TiO 2 ‐MMO composites in hydrogenation or methanation reactions.…”

Enhanced photocatalytic performance of (ZnO/CeO2)-β-CD system for the effective decolorization of Rhodamine B under UV light irradiation

“…The band gap energies of (ZnO/CeO 2 )-b-CD system is lower than that of (ZnO/CeO 2 ), ZnO and CeO 2 . It indicates that (ZnO/CeO 2 )-b-CD has higher photocatalytic activity than other samples (Almeida et al 2015;Li et al 2014). …”