Enhanced photocatalytic activity of bimodal mesoporous titania powders by C60modification.

In this work, fullerene modified TiO2nanocomposites (denoted as C60/TiO2) with low C60loadings (0–1.5 wt.%) have been prepared by a simple hydrothermal method using tetrabutylorthotitanate (TBOT, Ti(OC4H9)4) as the titanium precursor. The as-prepared C60/TiO2nanocomposites were characterized by X-ray diffraction, transmission electron microscopy, UV-visible spectrophotometry, nitrogen adsorption, and X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy. The formation of hydroxyl radicals (OH) on the surface of UV-illuminated TiO2is probed by photoluminescence using terephthalic acid as a probe molecule. Our results have demonstrated that C60molecules can be dispersed as a monolayer onto bimodal mesoporous TiO2viacovalent bonding. The photocatalytic oxidation rate of gas-phase acetone over C60/TiO2nanocomposites is greater than that over pure TiO2, commercial Degussa P25 (P25) and C60–TiO2counterparts prepared by simple impregnating mixing. In particular, 0.5 wt.% C60/TiO2nanocomposites show the greatest photocatalytic activity with the rate constant kexceeding that of P25 by a factor of 3.3. Based on the results of the current study, we propose that C60molecules doped onto TiO2act as “electron acceptors” responsible for the efficient separation of photogenerated charge carriers and the enhancement of photocatalytic activity. The proposed mechanism for the observed photocatalytic performance of C60/TiO2nanocomposites is further corroborated by experiments on hydroxyl radical and transient photocurrent response. [ABSTRACT FROM AUTHOR]