Synthesis and characterization of TiO2-x% curcumin nanocomposites (with x=3, 5, and 10): application to the photocatalytic degradation of methylene blue

The aim of this work is to prepare the nanocomposites TiO2/x%Curcumin (with x = 3, 5 and, 10) by wet impregnation method. Subsequently, these nanocomposites materials were successfully used for the photocatalytic degradation of a model dye, methylene blue (MB). The results obtained show good photocatalytic activity of said materials. An elimination conversion of 63% (which can be considered as the optimal value in this study) is obtained after 160 min at room temperature for an MB concentration of 10 mg/L for the TiO2/5%curcumin nanocomposite sample. This is due to the effect of adsorption, which is an important parameter controlling the degradation phenomenon. Indeed, the added curcumin causes an increase in the pH of the medium, which causes better adsorption of MB on the surface of the TiO2/5%curcumin nanocomposite material. Then, the TiO2/5%Curcumin nanocomposite material (the best in photocatalysis) was characterized by various analysis techniques: structural and optical, including Fourier Transform Infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Ultraviolet-Visible spectroscopy (UV-Vis.) and scanning electron microscopy (SEM). The results of the FT-IR analysis indicate a good homogeneity between TiO2 and Curcumin. Due to the reduced value of the gap energy (2.93 eV) of the TiO2/5%Curcumin nanocomposite material, determined from optical measurements, this nanocomposite material exhibits good semiconductor behavior. SEM analysis reveal that the average particle size of TiO2-anatase remains unchanged when adding curcumin.