Study On The Photocatalytic Activities And Free Radical Of T-ZnOw

In this paper, research progresses on the photocatalysts were compared and reviewed. The photocatalytic degradation of methyl orange by T-ZnOw was researched systematically under the UV-light irradiation. The effects of the initial concentration of methyl orange, the concentration of the photocatalyst, the species of the photocatalysts and the degradation kinetics were investigated, and the results of the experiments showed that the photocatalytic activity of T-ZnO whiskers accorded with the rule of first-order reaction, and the optimal concentration of T-ZnO whiskers was 2g/L. The experiments also indicated that the T-ZnO whisker was a good photocatalyst, which appeared better effect than that of the nano-TiO₂.In order to have a deep understand of the mechanism and the photocatalytic activity of the T-ZnOw, the metallic ion-doping and silver deposition was applied, respectively, to modify T-ZnOw. The results showed that the dopant of Fe³⁺, Cu²⁺ and V⁵⁺ could be loaded into the hexahedral lattice of ZnO, and the absorption bounds for the as-doped T-ZnOw spread to visible light. Suitable Ag-deposition on the surface of T-ZnOw could obviously enhance its photocatalytic activity. The leading factors influencing the generation of the free radical of hydroxyl in the system such as the excitation of light, morphologies of photocatalyst and methods of modification were investigated using Fe (phen)₃²⁺ as a quantitative reactant combined with spectrum analysis, and the results showed that the particle size and the modification affected the quantity of the free radicals of hydroxyl obviously. The modifications of as-doping and Ag-depositing extended the light response range, leading to visible light for photocatalytic activity.