<p>Sol-gel and dip-coating are common methods for preparing TiO₂ thin films. However, due to the incomplete hydrolysis of the precursor, the surface of TiO₂ nanoparticles still contains a lot of alkoxy groups, which has an adverse effect on the wettability of TiO₂ films. In this work, superhydrophilic TiO₂ films with enhanced photocatalytic performance were prepared by chemical modification of TiO₂ sol. FTIR spectroscopy and TGA verified that the carboxyl group was successfully grafted onto the surface of TiO₂ nanoparticles after two steps of modification. With the increase of the amount of modified reagents, the hydrophilic and photocatalytic properties of the film were gradually enhanced. When the mass of 3-triethoxysilylpropylamine (KH550) used reached 50% of the dry weight of TiO₂ (T-50), the film showed superhydrophilic and excellent photocatalytic properties. The enhanced wettability and photocatalytic performance make the modified TiO₂ films have greater advantages in the field of self-cleaning.</p> Graphical Abstract <p></p>