کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
62212 | 47627 | 2009 | 8 صفحه PDF | دانلود رایگان |
Photocatalytic activity of TiO2 particles embedded in mesoporous silica (TiO2@MPS), prepared by surfactant-templating method with a TiO2 colloidal suspension, has been studied in water with molecular oxygen. Photocatalytic reactions of several kinds of aromatic molecules with TiO2@MPS reveal that less polar substrates show high reactivity, while polar substrates show much lower reactivity. Electron spin resonance analysis with spin-trapping reagents reveals that less polar substrates diffuse easily into the pore of the catalysts and react efficiently with short-lived hydroxyl (OH) radicals formed at the surface of inner TiO2 particles, resulting in a high reactivity. In contrast, polar substrates cannot diffuse into the pores and hence, shows a low reactivity. The photocatalytic activity of TiO2@MPS driven by the substrate polarity is applicable to selective transformation of a less polar reactant to a polar product, such as hydroxylation of benzene to phenol with high selectivity (>69%).
TiO2 particles embedded in mesoporous silica show photocatalytic activity driven by substrate polarity. This TiO2@MPS system catalyzes the selective oxidation of benzene to phenol with high selectivity.Figure optionsDownload high-quality image (91 K)Download as PowerPoint slide
Journal: Journal of Catalysis - Volume 264, Issue 2, 10 June 2009, Pages 175–182