Facile sol–gel synthesis of Nd, Ce-codoped TiO₂ nanoparticle using starch as a green modifier: structural, optical and photocatalytic behaviors

In the present study, undoped TiO₂ and Nd–Ce-codoped TiO₂ nanoparticles with different molar ratios of dopants were synthesized by the sol–gel method using starch as a natural additive. Structural and optical properties were investigated by Fourier transform spectroscopy, UV–Vis spectroscopy, scanning electron microscopy, energy dispersive analytical X-ray, transmission electron microscopy, and X-ray diffraction methods. Moreover, the direct band gap was calculated by Tauc’s approach. Furthermore, photocatalytic activity of all samples has been investigated under UV irradiation in an aqueous medium. Compared with undoped TiO₂, the band gap of the Nd–Ce–TiO₂ samples decreases and depends on the content of dopants. In addition, photocatalytic activity improves in the presence of appropriate amount (1 mol%) of dopants.