Investigation of optical and morphological properties of dextrin and coumarin doped TiO2 films

Titanium dioxide (TiO2) is a widely used and researched material due to its properties such as brightness, non-toxicity, pure whiteness, physical and chemical stability. It is used in various fields due to its low cost. In this study, coumarin and dextrin doped TiO2 films were prepared on microscope slide substrates under various physical and chemical conditions using the sol-gel method. The TiO2 solution used for the coating process contains appropriate amounts of titanium (IV) n-butoxide, acetic acid and ethanol. The films were prepared using the spin coating method on substrates. The coated films were heat treated at 550 °C for 90 minutes and then they were analyzed. Structural analysis of the films was made using X-ray diffraction (XRD). It was determined that the films were in anatase structure. It was calculated that energy band gap of coumarin doped TiO2 films varied between 3.88 eV and 3.91 eV. It was calculated that energy band gap of dextrin doped TiO2 films varied between 3.81 eV and 3.87 eV. In optical measurements, it was determined that dextrin and coumarin doped films have high transmittance and low absorption. The surface structures of coumarin and dextrin doped TiO2 and undoped TiO2 films were investigated by Scanning Electron Microscopy (SEM). It was observed that the surfaces of the films were coated entirely and showed a homogeneous distribution. 2021, 47 pages Key Words: TiO2, sol-gel, dextrin, coumarin, optical properties, morphological properties