In the present work TiO2 coatings with different level of oxygen vacancy defect and different shapes of
nanosphere, nanocube, and nanopyramid were deposited on glass substrate by modified ultrasonic spray
pyrolysis method. The prepared coatings were successfully used for the photocatalytic degradation of
paraoxon pesticide under visible light irradiation. Based on the obtained results, among the papered coatings,
the TiO2 coating with nanopyramidal shape and oxygen vacancy defect has the highest photocatalytic
activity, and the lowest photocatalytic activity was observed in the case of the TiO2 coating with
nanospherical shape and without oxygen vacancy defect. The reason for these results is the sharp edges
and corners of nanopyramid which decreases the electron-hole recombination rate. Furthermore, presence
of oxygen vacancy defect improve the visible light photocatalytic activity via narrowing the band
gap energy and separation of the electron-hole.