Direct synthesis of highly ordered Ti-containing Al-SBA-15 mesostructured catalysts from natural halloysite and its photocatalytic activity for oxidative desulfurization of dibenzothiophene

Here we show that bimetallic Ti-Al-SBA-15 materials were synthesized successfully from titanium tetraisopropoxide (TTIP) and natural halloysite clay via the direct hydrothermal method. The results revealed that the incorporation of titanium species in the Al-SBA-15 framework retained the characteristic peaks and possessed an increased Brunauer-Emmett-Teller (BET) surface area in comparison to the conventional Al-SBA-15 material. The successful isomorphous substitution of titanium in the Al-SBA-15 framework was confirmed by X-ray photoelectron spectroscopy (XPS) and Raman spectroscopies. The transmission electron microscopy (TEM) images showed that the composite material exhibited a highly ordered 2-D hexagonal mesostructure. The photocatalytic activity of these Ti-Al-SBA-15 mesoporous materials were assessed by dibenzothiophene (DBT) conversion under UV light irradiation, showing that the Al-SBA-15 sample containing 7.5 wt.% of titanium possessed the highest photocatalytic activity with a conversion of 92.68% at 70 oC and maintained the catalytic performance after four cycles. These results suggest a promising technique to produce the Ti-Al-SBA-15 photocatalyst from an abundant and low-cost clay material.