Photocatalytic Degradation of Different VOCs in the Gas-Phase over TiO2 Thin Films Prepared by Ultrasonic Spray Pyrolysis

In this study, we deposited TiO 2 thin films onto borosilicate glass by ultrasonic spray pyrolysis at 350 and 450 °C. The aim of study is to determine the effect of deposition temperature on photocatalytic activity of TiO 2 thin films and to investigate the performance of TiO 2 thin films on photocatalytic degradation of methyl tert-butyl ether (MTBE), acetone, acetaldehyde, and heptane as functions of different operating parameters. TiO 2 thin films deposited at 350 and 450 °C have a thickness value of 190 and 330 nm, respectively. All as-prepared TiO 2 films possess an anatase crystalline structure. According to the X-ray photon spectroscopy (XPS) study, the TiO 2 thin film deposited at 350 °C showed a higher amount of oxygen vacancies and hydroxyl groups on the film surface after UV treatment. The aged-TiO 2 thin film deposited at 350 °C showed a water contact angle (WCA) value of 0° after 10 min UV irradiation, showing superhydrophilic surface behavior. The TiO 2 film deposited at 350 °C exhibited the highest amount of conversion of MTBE (100%). The results also showed that TiO 2 films are capable of photocatalytic degradation of MTBE (100%) and acetaldehyde (approx. 80%) in humid air conditions and high airflow rate. The visible-light-activity of TiO 2 thin films was tested with 5 ppm MTBE and acetone. TiO 2 thin films deposited at 350 °C with a surface area of 600 cm 2 showed 60% of MTBE and 33% of acetone degradation under VIS light. View Full-Tex