Ag/TiO2/β-CD nano composite: Preparation and photo catalytic properties for methylene blue degradation

摘要

In this paper, Ag/TiO2/beta-cyclodextrin (β-CD) nano composite was successfully synthesized as a novel friendly nano photo catalyst with ability of loading various compounds. The influence of different β-cyclodextrin content in the formation of nano composites was investigated. Various analysis including FTIR, dynamic light scattering (DLS), diffuse reflectance spectroscopy (DRS), XRD, FESEM, EDAX, and TEM were used to characterize the prepared nano composites. The presence of β-CD in the nano composite was confirmed by FTIR patterns. FE-SEM pictures indicated roughly spherical particles and DLS results showed the average hydrodynamic diameters of 95 nm in aqueous dispersion that was bigger with more β-CD. TEM images confirmed the presence of three compounds in the nano composites. The peak intensity and the spectra intensity in the visible region increased with more β-CD confirming synthesis of more Ag on TiO2. The effective role of β-CD as stabilizer was also proved by the low reduction of the peak intensity for various nano composites after 15 days. One factor response surface methodology (RSM) was applied to model Methylene Blue degradation rate by Ag/TiO2/β-CD under UV irradiation. The mathematical model suggested significant improvement in the photo degradation rate of Ag/TiO2/β-CD in comparing with Ag/TiO2. However, more β-CD limitedly improved the degradation rate of Methylen Blue and excess β-CD was detrimental on the reduction of photo degradation rate.