We improve the photocatalytic effect of Ag 2 S under visible light by using fullerene modified with Ag 2 S nanoparticles. Surface areas and pore volumes of the Ag 2 S-fullerene samples showed catastrophic decreases due to the deposition of Ag 2 S. The generation of reactive oxygen species was detected through the oxidation reaction from 1,5-diphenyl carbazide (DPCI) to 1,5-diphenyl carbazone (DPCO). It is found that the photocurrent density and the photocatalytic effect increase in the case with the modified fullerene. In comparison with the separate effects of Ag 2 S and fullerene nanoparticles, the photocatalytic effect of the fullerene modified with Ag 2 S composites is increased significantly due to the synergetic effect between the fullerene and the Ag 2 S nanoparticles.

Platinum treated fullerene/TiO 2 composites (Pt-fullerene/TiO 2 ) were prepared using a sol-gel method. The composite obtained was characterized by FT-IR, BET surface area measurements, X-ray diffraction, energy dispersive X-ray analysis, transmission electron microscopy (TEM) and UV-vis analysis. A methyl orange (MO) solution under visible light irradiation was used to determine the photocatalytic activity. Excellent photocatalytic degradation of a MO solution was observed using the Pt-TiO 2 , fullerene-TiO 2 and Pt-fullerene/TiO 2 composites under visible light. An increase in photocatalytic activity was observed and Pt-fullerene/TiO 2 has the best photocatalytic activity, which may be attributable to increase of the photo-absorption effect by the fullerene and the cooperative effect of the Pt.

SUMMARYNumerical simulation of CO 2 addition effects to fuel and oxidizer streams on flame structure has been conducted with detailed chemistry in H 2 -O 2 diffusion flames of a counterflow configuration. An artificial species, which displaces added CO 2 in the fuel-and oxidizer-sides and has the same thermochemical, transport, and radiation properties to that of added CO 2 , is introduced to extract pure chemical effects in flame structure. Chemical effects due to thermal dissociation of added CO 2 causes the reduction flame temperature in addition to some thermal effects. The reason why flame temperature due to chemical effects is larger in cases of CO 2 addition to oxidizer stream is well explained though a defined characteristic strain rate. The produced CO is responsible for the reaction, CO 2 +H=CO+OH and takes its origin from chemical effects due to thermal dissociation. It is also found that the behavior of produced CO mole fraction is closely related to added CO 2 mole fraction, maximum H mole fraction and its position, and maximum flame temperature and its position.

WO3-treated fullerene/TiO2 composites (WO3-fullerene/TiO2) were prepared using a sol-gel method. The composite obtained was characterized by BET surface area measurements, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, transmission electron microscopy, and UV-vis analysis. A methyl orange (MO) solution under visible light irradiation was used to determine the photocatalytic activity. Excellent photocatalytic degradation of a MO solution was observed using the WO3-fullerene, fullerene-TiO2, and WO3-fullerene/TiO2 composites under visible light. An increase in photocatalytic activity was observed, and WO3-fullerene/TiO2 has the best photocatalytic activity; it may attribute to the increase of the photo-absorption effect by the fullerene and the cooperative effect of the WO3.

In this study, we prepared graphene by using the modified Hummers-Offeman method and then introduced the metals (Pt, Pd and Fe) for dispersion on the surface of the graphene for synthesis of metal-graphene composites. The characterization of the prepared graphene and metal-graphene composites was performed by X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis and transmission electron microscopy (TEM). According to the results, it can be observed that the prepared graphene consists of thin stacked flakes of shapes having a well-defined multilayered structure at the edge. And the metal particles are dispersed uniformly on the surface of the graphene with an average particle size of 20 nm.

No abstract

CdS-TiO2 and CdS-C60/TiO2 were prepared using C60, cadmium acetate dehydrate [(CH3COO)2Cd·2H2O], sodium sulfide (Na2S·5H2O) and titanium (IV) n-butoxide by a sol-gel method. The prepared sonocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and transmission electron microscopy (TEM). A rhodamine B (RhB) solution under ultrasonic irradiation was used to determine the catalytic activity. Excellent catalytic degradation of an RhB solution was observed using the CdS-C60/TiO2 composites under ultrasonic irradiation. C60 coupled CdS-TiO2 can enhance the Brunauer-Emmett-Teller (BET) surface area and increase the decolorization rate for rhodamine B solution. The results also shows that increase the content of CdS can enhance the catalytic activity.

No abstract