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Abstract: In this study, the structural variations, surface states, and mass transformations of fullerene [C60] derivatives were investigated through the preparation of Pt-decorated oxidized fullerene and a Pt-fullerene/TiO2 composite and comparison to an oxidized fullerene [C60O]. These derivatives were synthesized with an improved oxidation method using m-chloroperbenzoic acid (MCPBA). Weak and strong peaks of metallic platinum and titanium dioxide, along with weak pristine fullerene [C60] peaks, were observed in the XRD patterns for the Pt-fullerene and Pt-fullerene/TiO2 composite. SEM micrographs for the metallic Pt-fullerene and Pt-fullerene/TiO2 composite indicated that practically all the platinum and titanium dioxide that were introduced were located on the carbon cages and consequently, were dispersed into very small crystallites with growth of platinum metals and titanium dioxide. The EDX spectra of Pt-fullerene and Pt-fullerene/TiO2 composite showed the presence of C, O, and Pt, with strong Ti peaks. From the MALDI-TOF mass spectra, the differences in the spectra for the three kinds of fullerene derivatives were due to oxidation including chemical bonding and interposing of metallic platinum and titanium dioxide in the fullerene [C60] molecules. And, absorption property demonstrated by UV–vis diffuse reflectance method. From the photocatalytic results, the excellent activity of the Pt-fullerene/TiO2 composites for organic dye and UV irradiation time could be attributed to the synergetic effects between photocatalysis of the supported TiO2 and absorptivity of the platinum and fullerene. [Copyright &y& Elsevier]

Abstract: The effect of Fe treatment on the Fe-activated carbon fiber (ACF)/TiO2 composite catalysts was studied. Then the characterizations of Fe-ACF/TiO2 composite catalysts were determined by employing BET, SEM, XRD and EDX instruments to analyze the potential factors. The adsorption data showed that the composites had decreased surface compared with the pristine ACF. From the results, it was shown the blocking of the micropores on the surface of ACF by treatment of Fe compound and Ti source. SEM micrographs for the Fe-ACF/TiO2 composite catalysts indicated that practically all the ferric compounds and titanium dioxide introduced were located onto the ACF surfaces and consequently, there were dispersed into very small crystallites with growth of titanium dioxide. The XRD results showed patterns for the anatase and rutile typed titanium dioxide structure with a Fe mediated compound from the composites. The EDX results showed that the presence of C and O with Ti peaks on the Fe-ACF/TiO2 composites decreased with an increase Fe concentration incorporated. Finally, organic dye (MB) decomposition showed the synergetic effects of adsorption, photo-degradation and enhancement of photonic activity of Fe component. [Copyright &y& Elsevier]

Gold nanoparticles stabilized by thiolates derived from normal and -functionalized alkane- and arenethiols (HS(CH2)nCH3, HS(CH2)10COOH, HS(CH2)11OH, HSC6H4NH2, HSCH2CH2C6H5, and HSCH2C6H4C(CH3)3) were synthesized. Differences in their chemical and ultrasonic stabilities were studied using UV−vis spectroscopy. The results showed that these stabilities of monolayer-protected nanoparticles were greatly influenced by the structure and functionality of the monolayer surrounding a nanoparticle core. The selective functionalization of the nanoparticle allowed us to prepare hybrid nanostructures (nanoparticle multilayer assemblies) with different compositions and functionalities. This paper also presents an investigation of the chemical, thermal, and ultrasonic treatments of these nanoparticle multilayer assemblies. The results suggest that the linkers used to build nanoparticle multilayer films govern the overall stability of hybrid nanostructures.

Abstract: The reaction of C60, under ultrasonication, with various oxidants, such as 3-chloroperoxy benzoic acid (Fluka 99%), 4-methyl morpholine N-oxide (Aldrich 97%), chromium (VI) oxide (Aldrich 99.9%), and the oxone monopersulfate compound, causes the oxidation of fullerenes at room temperature. The FAB-MS spectra and HPLC profile confirmed that the products of fullerene oxidation were [C60(O)n] (n=1∼3 or n=1). C70 also reacted, under ultrasonication, with various oxidants, but the reaction rate of C70 was lower than that of C60.