Details

Autor(en) / Beteiligte

• Seftel, E.M.
• Mertens, M.
• Cool, P.

Titel

The influence of the Ti4+ location on the formation of self-assembled nanocomposite systems based on TiO2 and Mg/Al-LDHs with photocatalytic properties

Ist Teil von

• Applied catalysis. B, Environmental, 2013-05, Vol.134-135, p.274-285

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2013

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• [Display omitted] ► TiO2/LDH nanocomposites were obtained using the memory effect property of LDH materials. ► The influence of the Ti4+ location on the quality of the products was investigated. ► Up to 93% of dye could be removed by the obtained TiO2/LDH nanocomposites. Herein, we report the formation of TiO2/LDH self-assembled nanocomposite systems using the memory effect property of the layered clay-type materials. Two different synthesis approaches, based on the modification of the initial brucite-like sheets composition, were used in order to investigate the influence of the Ti4+ location on the quality of the final products: the reconstruction of a calcined MgAl-LDH in a TiOSO4·xH2O aqueous solution and the reconstruction of a calcined MgAlTi-LDH in aqueous solution. The reconstruction process, monitored using X-ray diffraction, IR spectroscopy, UV–vis diffuse reflectance spectroscopy, SEM and thermal analysis, produced different structural changes strongly related with the brucite-like sheets composition. The photocatalytic activity of the obtained nanocomposite systems was evaluated for the degradation of the methyl-orange (MO) dye. An intimate contact has been created between the anatase and the brucite-like sheets in the nanocomposite systems, which had a direct influence on the HO radical production enhancing thus the photocatalytic performances. When comparing the as-synthesized catalysts, the MgAlTi-LDH solid manifests very powerful photocatalytic effect due to the segregation of small, well defined TiO2 nanoparticles on the highly hydroxilated layered surface. Up to 93% of the dye could be removed by a TiO2/LDH-type nanocomposite system. Controlled thermal treatment of photocatalytic systems allowed us to tailor the quality of the photocatalytic active sites deposited on the layered support. The use of the TiO2/LDHs nanocomposites showed multiple advantages highlighted by the increased activity per mass, higher efficiencies at a decreased solid/liquid ratio, decreased reaction times, reduced agglomeration and easy to separate at the end of the processes.