This study employs a direct-synthesis method to produce titania (TiO2)/water nanofluid, which is a working fluid involved in the electrophoretic deposition (EPD) of nanophotocatalytic films. In general, using organic solvents and water as the bulk liquids in EPD produces environmental pollution and defective films due to the electrolysis of water. To mitigate water electrolysis, the fabrication method proposed in this study adds an anionic dispersant to the TiO2/water nanofluid. The anionic dispersant changes the surface charge of TiO2 nanoparticles to facilitate their deposition on the anode. For low voltage EPD processes, this method effectively improves defective nanophotocatalytic films. These defects are caused by bubbles from the water electrolysis, as the volume of oxygen produced at the anode amounts to half of the hydrogen produced at the cathode. The objective of this study is to propose empirical equations describing the relationship between film thickness and electric parameters.