Effects of pH and polyethylene glycol on surface morphology of TiO2 thin film

In this investigation, a sol gel procedure for preparation of TiO2 thin films was developed using polyethylene glycol (PEG). Effect of pH on the structure of the films was also investigated. The morphology and surface structure of the films were studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM). It was found that the films from the base sols had a porous structure and the surface was considerably rough. However, the films made by the acid sols were very dense and had a relatively smoother surface. It was also found that by using PEG, the surface area of the film became larger as a result of the increase in the film porosity. BET analysis confirmed the increase in the surface area which enhanced the photocatalytic activity of TiO2 thin film in degradation of Malachite Oxalate Green.