Synthesis of hectorite-TiO2 and kaolinite-TiO2 nanocomposites with photocatalytic activity for the degradation of model air pollutants

• Published in: Applied clay science 2009, Vol.42 (3-4), p.563-568
• Main Authors: KIBANOVA, Daria, TREJO, Martin, DESTAILLATS, Hugo, CERVINI-SILVA, Javiera
• Format: Article
• Language: English
• Subjects: Earth sciences; Earth, ocean, space; Exact sciences and technology; Mineralogy; Silicates
• ISSN: 0169-1317; 1872-9053
• DOI: 10.1016/j.clay.2008.03.009

The synthesis and photocatalytic activity of small-sized TiO2 supported on hectorite and kaolinite were studied. TiO2 was deposited on the clay mineral surface by a sol-gel method with titanium isopropoxide as precursor. Anatase TiO2 particle formation was achieved by hydrothermal treatment at 180 C. Material characterisation was conducted using XRD, SEM, XPS, ICP-OES, BET and porosimetry analysis. Efficiency in synthesising clay-TiO2 composites depended strongly on the clay mineral structure. Incorporation of anatase in hectorite, an expandable clay mineral, was very significant ( > 36 wt% Ti) and to be followed by important structural changes at the clay mineral surface. No major structural modifications of the clay were observed for kaolinite-TiO2, compared with the untreated material. The photocatalytic performance of clay-TiO2 composites was evaluated by ATR-FTIR following the oxidation of adsorbed toluene and d-limonene, two model air pollutants. In either case, the photocatalytic removal efficiency of these hydrophobic substrates by the synthesised clay-TiO2 composites was comparable to that observed using pure commercial TiO2.