LDH-VB9-TiO2 and LDH-VB9-TiO2/crosslinked PVA nanocomposite prepared via facile and green technique and their photo-degradation application for methylene blue dye under ultraviolet illumination

Abstract

Vitamin B9 (VB9) as a biological molecule was used for the intercalation of MgAl-layered double hydroxide (LDH) which can increase the active sites and organic nature of LDH samples. Then, the LDH-VB9-TiO₂ composite was synthesized with mass ratio of LDH-VB9:TiO₂ equal to 1:1 through ultrasonic technique as a green and environmentally approach, and then the LDH-VB9-TiO₂ was applied with three different mass ratios as organic-inorganic fillers in order to prepare in-situ crosslinked poly(vinyl alcohol) (CSPVA) nanocomposites (NC)s. The physio-chemical structure of CSPVA NCs was studied with variety of analyses such as FT-IR, XRD, FE-SEM, TEM and TGA. Finally, the prepared compounds were used for the photo-degradation of methylene blue (MB) dye from aqueous solution under ultraviolet lights. The photo-degradation performance of samples showed that the rate constant of K_app was in the order of LDH-VB9-TiO₂ > TiO₂ > LDH-VB9/TiO_2-CSPVA NC. Moreover, the value of half-life for degradation of MB dye was very remarkable for LDH-VB9-TiO₂ sample (t_1/2 = 81.53 min) in compared to the MB degradation without any photocatalyst sample (t_1/2 = 6930 min). So, it can be concluded that the LDH-VB9 with nano-sheet structure has significant effect on the photo-degradation of MB dye in the presence TiO₂. These kinds of NCs can be used as economy and environmentally friendly compounds in the industrial applications such as water purification.