In the present work, WO3 and WO3-TiO2 were prepared by the chemical deposition method. Structural variations, surface state and elemental compositions were investigated for preparation of WO3-TiO2 sonocatalyst. X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and transmission electron microscopy (TEM) were employed for characterization of these new photocatalysts. A rhodamine B (Rh.B) solution under ultrasonic irradiation was used to determine the catalytic activity. Excellent catalytic degradation of an Rh.B solution was observed using the WO3-TiO2 composites under ultrasonic irradiation. Sonocatalytic degradation is a novel technology of treating wastewater. During the ultrasonic treatment of aqueous solutions sonoluminescence, cavitaties and "hot spot" occurred, leading to the dissociation of water molecules. In case of a WO3 coupled system, a semiconductor coupled with two components has a beneficial role in improving charge separation and enhancing TiO2 response to ultrasonic radiations. In case of the addition of WO3 as new matter, the excited electrons from the WO3 particles are quickly transferred to TiO2 particle, as the conduction band of WO3 is 0.74 eV which is -0.5 eV more than that of TiO2. This transfer of charge should enhance the oxidation of the adsorbed organic substrate. The result shows that the photocatalytic performance of TiO2 nanoparticles was improved by loading WO3.

AC and ZnS modified TiO2 composites (AC/ZnS/TiO2) were prepared using a sol-gel method. The composite obtained was characterized by Brunauer-Emmett-Teller (BET) surface area measurements, X-ray diffraction (XRD), energy dispersive X-ray (EDX) analysis, scanning electron microscope (SEM) analysis, and according to the UV-vis absorption spectra (UV-vis). XRD patterns of the composites showed that the AC/ZnS/TiO2 composites contain a typical single and clear anatase phase. The surface properties as observed by SEM present the characterization of the texture of the AC/ZnS/TiO2 composites, showing a homogenous composition in the particles showing the micro-surface structures and morphology of the composites. The EDX spectra of the elemental identification showed the presence of C and Ti with Zn and S peaks for the AC/ZnS/TiO2 composite. UV-vis patterns of the composites showed that these composites had greater photocatalytic activity under visible light irradiation. A rhodamine B (Rh.B) solution under visible light irradiation was used to determine the photocatalytic activity. The degradation of Rh.B was determined using UV/Vis spectrophotometry. An increase in the photocatalytic activity was observed. From the photocatalytic results, the excellent activity of the Y-fullerene/TiO2 composites for the degradation of methylene blue under visible irradiation could be attributed to an increase in the photo-absorption effect caused by the ZnS and to the cooperative effect of the AC.

In this study, we used coal-based activated carbons and charcoal as startingmaterials, phenolic resin (PR) as a binder, and TOS as a titanium source to prepare TiO2 combining spherical shaped activated carbon photocatalysts. The textural properties of the activated carbon photocatalysts (SACP) were characterized by specific surface area (BET), energy dispersive X-ray spectroscopy (XRD), scanning electron microscopy (SEM), iodine adsorption, strength intensity, and pressure drop. The photocatalytic activities of the SACPs were characterized by degradation of the organic dyes Methylene Blue (MB), Methylene Orange (MO), and Rhodamine B (Rh. B) and a chemical oxygen demand (COD) experiment. The surface properties are shown by SEM. The XRD patterns of the composites showed that the SACP composite contained a typical single, clear anatase phase. The EDX spectro for the elemental indentification showed the presence of C and O with Ti peaks. According to the results, the spherical activated carbon photocatalysts sample of AOP prepared with activated carbon formed the best spherical shape, a high BET surface area, iodine adsorption capability and strength value, and the lowest pressure drop, and the photocatalytic activity was better than samples prepared with charcoal. We compared the degradation effects among three kinds of dyes. MB solution degraded with the SACP is better than any other dye solutions.

The composite photocatalysts of a Fe-modified carbon nanotube (CNT)-TiO2 were synthesized by a two-step sol-gel method at high temperature. Its chemical composition and surface properties were investigated by BET surface area, scanning electron microscope (SEM), Transmission Electron Microscope (TEM), X-ray diffraction (XRD) and ultraviolet-visible (UV-Vis) spectroscopy. The results showed that the BET surface area was improved by modification of Fe, which was related to the adsorption capacity for each composite. Interesting thin layer aggregates of nanosized TiO2 were observed from TEM images, probably stabilized by the presence of CNT, and the surface and structural characterization of the samples was carried out. The XRD results showed that the Fe/CNT-TiO2 composites contained a mix of anatase and rutile forms of TiO2 particles when the precursor is TiOSO4·xH2O (TOS). An excellent photocatalytic activity of Fe/CNT-TiO2 was obtained for the degradation of methylene blue (MB) under visible light irradiation. It was considered that Fe cation could be doped into the matrix of TiO2, which could hinder the recombination rate of the excited electrons/holes. The photocatalytic activity of the composites was also found to depend on the presence of CNT. The synergistic effects among the Fe, CNT and TiO2 components were responsible for improving the visible light photocatalytic activity.

In this paper, Fe-TiO2 and Fe-fullerene/TiO2 composite photocatalysts were prepared with titanium (IV) n-butoxide (TNB) by a sol-gel method. TiO2, Fe-TiO2 and Fe-fullerene/TiO2 were characterized by scanning electron microscopy (SEM), Transmission electron microscope (TEM), specific surface area (BET), X-ray diffraction analysis (XRD) and energy dispersive X-ray spectroscopy (EDX). The photocatalytic activities were evaluated by the photocatalytic oxidation of methylene blue (MB) solution. XRD patterns of the composites showed that the photocatalyst composite contained a typical single and clear anatase phase. The surface properties shown by SEM presented a characterization of the texture on Fe-fullerene/TiO2 composites and showed a homogenous composition in the particles for the titanium sources used. The EDX spectra for the elemental identification showed the presence of O, C and Ti elements. Moreover, peaks of the Fe element were observed in the Fe-TiO2 and Fe-fullerene/TiO2 composites. The degradation of MB solution by UV-light irradiation in the presence of photocatalyst compounds was investigated in complete darkness. The degradation of MB concentration in aqueous solution occurred via three kinds of physical phenomena: quantum efficiency of the fullerene; organo-metallic reaction of the Fe compound; and decomposition of TiO2. The degradation rate of the methylene blue solution increased when using Fe-fullerene/TiO2 compounds.

Titanium dioxide (TiO2) particles deposited on different quantitative Fe-treated carbon nanotube (CNT) composites with high photocatalytic activity of visible light were prepared by a modified sol-gel method using TNB as a titanium source. The composites were characterized by BET, XRD, SEM, TEM and EDX, which showed that the BET surface area was related to the adsorption capacity for each composite. From TEM images, surface and structural characterization of for the CNT surface had been carried out. The XRD results showed that the Fe-ACF/TiO2 composite mostly contained an anatase structure with a Fe-mediated compound. EDX results showed the presence of C, O, and Ti with Fe peaks in the Fe-CNT/TiO2 composites. The photocatalytic activity of the composites was examined by degradation of methylene blue (MB) in aqueous solution under visible light, which was found to depend on the amount of CNT. The highest photocatalytic activity among the different composites was related to the optimal content of CNT in the Fe-CNT/TiO2 composites. In particular, the photocatalytic activity of the Fe-CNT/TiO2 composites under visible light was better than that of the CNT/TiO2 composites due to the introduction of Fe particles.

In this study, the effects of silver treatment and activation on the physical and chemical properties of spherical activated carbon (SAC) were studied. The textural properties of SAC were characterized by BET surface area, XRD, SEM, iodine adsorption, strength intensity, pressure drop and antibacterial effects. BET surface areas of SACs decreased with an increase of the amount of PR before and after activation, and the BET surface areas of SACs were found to be about 2-3 times the size of those before activation. The XRD patterns showed their existing state as stable Ag crystals and carbon structure. The Ag particles are seaweedlike and uniform, being approximately 5-10 μm in size deposited on the surface of activated carbon. All of the samples had much more iodine adsorption capability after activation than before activation. The strength values of SACs increased with an increase of the amount of PR, and there was a smaller drop in the strength values of SACs with silver treatment than with non-silver treatment after activation. The Ag-SAC composites showed strong antibacterial activity against Escherichia coli (E. Coli).