Ultrasonically sprayed undoped and indium-doped titanium oxide thin films for methylene blue degradation: Effect of molarity and irradiation time.

Undoped and Indium- 3 at % doped titanium oxide thin films were deposited at 450 °C by ultrasonic spray pyrolysis technique on glass substrates. The molarity content in the starting solution was varied from 0.1 to 0.2 M to study its effect on the degradation of methylene blue (MB) dye in the photocatalytic process. X-ray diffraction patterns confirm the anatase structure of TiO2. A maximum MB degradation of about 60 % was achieved for a UV light exposition time of 210 min. The degradation behavior with respect to UV exposition time showed a linear relationship with the concentration of charge carriers, which is explicated in this work. The indium doped titanium oxide thin films deposited with 0.2 M are relatively more promising for MB degradation when the UV exposure times are larger than 120 min.