Noble Metal-Modified Porous Titania Networks and their Application as Photocatalysts.

Abstract

In order to enhance the photocatalytic activity of titania materials, which suffer from high percentages of photon-induced electron and hole pair recombination, noble metal (Pd, Au, Ag, and Pt) modified porous titania materials were prepd. A modified deposition pptn. technique was used to deposit the metal onto a porous TiO2 support preformed using an agarose gel templating technique coupled with sol-gel chem. The final composites were characterized by use of SEM-EDX, TEM, XRD, diffuse reflectance UV/Vis spectroscopy, XPS, FTIR, inductively coupled plasma mass spectroscopy, zeta potential, and secondary ion mass spectrometry. The photocatalytic activity of the samples was investigated by monitoring changes in methylene blue concn. under UV light irradn. The photocatalytic activity was enhanced significantly, relative to the pure titania support, by Pd (63 %) and Au (31-37 %), and slightly by Ag (24 %) and Pt (12 %) at the resp. optimum metal deposition amt. A uniform distribution of metal in the TiO2 network, the metallic form of the noble metal, and an increased org. pollutant adsorption contributed pos. to the photocatalytic activity of the final materials.