Enhancement Of Photocatalytic Perfomances Of C₆₀ Surface Modified Photocatlysts

C₆₀ modified photocatalysts were prepared by adsorbing C₆₀ molecular on the surface of photocatalysts nanoparticles in toluene solution. HRTEM, TG-DTA, DRS, Raman, PL, EIS and ESR were used to study the structure, optical properties and the photocatalytic processes of as-prepared samples, and the photocatalitic performances of the C₆₀-modified photocatalysts were also studied by decomposing salicylic acid, formaldehyde, methylene blue and Rhodamine B. The main results are as follows: (1) C₆₀ modified TiO₂ (P-25) photocatalyst was prepared by adsorbing C₆₀ molecular on the surface of TiO₂ (P-25) nanoparticles in toluene solution. C₆₀ was bonded on the surface of TiO₂ photocatalyst with monomolecular layer state. TiO₂ photocatalyst modified by C₆₀ exhibited dramatic enhancement of photocatalytic activity and the photocatalytic activity of photocatalyst modified by 2.5 wt% C₆₀ raised about 4.0 times and 1.5 times respectively compared with TiO₂ (P-25) for the decomposition of the aqueous salicylic acid and the gaseous formaldehyde under ultraviolet (UV) light irradiation. The photoelectrochemical results showed that the photocurrent of TiO₂ increased 4 times after being modified by C₆₀. The enhancement of photocatalytic activity was attributed to the high charge separation rate promoted by synergetic effect of C₆₀ monomolecular layer and TiO₂ particles.(2) Fullerene (C₆₀)-modified Bi₂WO₆ photocatalyst is prepared by a simple absorbing process. The as-prepared samples show high efficiency for the degradation of nonbiodegradable azodyes Methylene Blue (MB) and Rhodamine B (RhB) under visible light (λ> 420 nm) and simulative sunlight (λ> 290 nm). After being modified by C₆₀, the photocatalytic activities of Bi₂WO₆ samples increase about 5.0 and 1.5 times for the degradation of MB and RhB under visible light irradiation, while 4.6 and 2.1 times under xenon lamp irradiation, respectively. The optimum synergetic effect is found at a weight ratio of 1.25 wt % (C₆₀/Bi₂WO₆). The enhanced photocatalytic activity for C₆₀-modified Bi₂WO₆ is likely due to the high migration efficiency of photoinduced electrons on the interface of C₆₀ and Bi₂WO₆, which is produced by the interaction of Bi₂WO₆ and C₆₀ with conjugativeÏ€-system. Further experiments show that the photocatalytic reaction process of C₆₀-modified Bi₂WO₆ is mainly governed by direct holes and O2?- oxidation.(3) C₆₀-modified ZnO photocatalyst is prepared by a simple absorbing process. The modification of C₆₀ not only enhanced the photocatalytic activity of ZnO, but also inhibited the photo-corrosion of ZnO. The photocatalitic performance of C₆₀-modified ZnO was studied by decomposing methylene blue under UV irradiation. The photoactivity of C₆₀/ZnO (1.5%) was 2 times higher than that of ZnO. C₆₀ promotes the separation of photo-induced electrons and holes, enhances the photoactivity. At the same time, C₆₀ bonds with surface O atom of ZnO, reduces the activity of O atom, so the photo-corrosion is inhibited.