γ-CD-Functionalized TiO2 Nanoparticles For the Photocatalytic Degradation of Organic Dyes

In this work, an efficient photocatalyst based on gamma-cyclodextrin-modified titanium dioxide nanoparticles (TiO2/γ-CD NPs) was synthesized and used for photocatalytic degradation of rhodamine B (RhB), methyl orange (MO) and methylene blue (MB). The results of FESEM, EDX, TEM, FT-IR, XRD and BET surface area measurement showed that the TiO2 NPs were effectively modified with γ-CD. The photocatalytic properties of the TiO2/γ-CD NPs were evaluated by the degradation of some organic dyes in aqueous solution under ultraviolet (UV) light illumination. The experimental results confirmed that the TiO2/γ-CD had exhibited efficient photocatalytic activities higher than that of the pure TiO2 in the degradation of investigated dyes. The γ-CD could increase the lifetime of the excited states of the unreactive guests and facilitate electron transfer from the excited dye to TiO2 conduction band. The results indicated that the first-order kinetic model well describes the degradation of the dyes by TiO2/γ-CD NPs. the photocatalytic reaction rate constants for RhB, MO and MB dyes in the presence of TiO2/γ-CD NPs were 4, 5.6 and 4.2 times higher than that of pure TiO2, respectively. In addition, the TiO2/γ-CD NPs can be used for several times in real application as an effective photocatalyst.