Electrophoretic Deposition of TiO2 Thin Films for Photocatalytic Degradation of Organic Pollutants in Water

Abstract

In this study, electrophoretic deposition (EPD) technique was used to deposit titanium dioxide (TiO₂) thin films on conducting glass substrates for application in photocatalytic degradation of organic pollutants in water. 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  are ethanol, a TiO₂ solid loading of 4 wt%, a 0.2 wt% iodine concentration in the solvent and a deposition voltage of 20 V in a time of 3.5 minutes. The photocatalytic activity of TiO₂ thin films decreased exponentially with the ultraviolet light (UV) illumination time and it was also dependent on film thickness, and sintering temperature of the TiO₂ thin films. Highest rate of photocatalytic activity was observed at an optimal film thickness of 95 ± 2 µm sintered at 300 °C. The implications of these results are discussed for design of inexpensive wastewater purification systems for light industries as well for semi urban small communities.

Keywords: Electrophoretic deposition; Titanium dioxide