Electrophoretic Deposition of Titanium Dioxide Thin Films for Photocatalytic Water Purification Systems

Abstract

In this study, electrophoretic deposition (EPD) technique was used to deposit titanium dioxide (TiO2) thin films on conducting glass substrates for application in water purification from organic contaminants. Phenol was used as a model pollutant. The EPD suspension related parameters and deposition conditions were first optimized for good quality film deposits. The suspension stability and deposition conditions that result in good adherence of TiO2 particles to the substrate with homogeneous film coatings, is ethanol with a pH of 3.0, a TiO2 solid loading of 4.0 wt%, a 0.2 wt% iodine concentration in the solvent and a deposition voltage of 20.0V in a time of 210.0s. The photocatalytic activity of TiO2 thin films decreases exponentially with the ultraviolet light (UV) illumination time and it is also dependent on film thickness, sintering temperature and the intensity of the UV light. Highest rate of photocatalytic activity is observed at an optimal film thickness of 95.0 ± 2.0µm sintered at 300.0°C. The implications of these results are discussed for design of inexpensive waste water purification systems for light industries before discharge into the ecosystem.