OICC Press Iranian Journal of Catalysis 2345-4865 6 3 2024 02 03 Effects of Ag, Nd codoping on structural, optical and photocatalytic properties of TiO2 nanocomposite synthesized via sol-gel method using starch as a green additive EN Maryam Bordbar Department of Chemistry, Faculty of Science, University of Qom, Qom, Iran. Journal Article 2024 02 03 In this paper, undoped TiO2 and Ag-Nd-codoped TiO2 nanocomposites with different molar ratios of dopants were synthesized by the sol-gel method using starch as a natural additive. Structures were investigated by FT-IR and UV–Vis spectroscopy, SEM, and XRD methods. Moreover, the direct band gap was calculated by Tauc's approach. Furthermore, photocatalytic activity of all samples were investigated under UV irradiation in an aqueous medium. Compared with undoped TiO2, the band gap of the Ag-Nd -TiO2 samples decreases and depends on the content of dopants. In addition, photocatalytic activity improves in the presence of appropriate amount (1.5 mol%) of Ag and Nd as dopants.