Synthesis, Characterization and Application of Photocatalytic Titanium Dioxide Films for Water and Air Purification

Introduction. Intensive research is currently focused on identifying materials suitable for the development of ad-vanced gas sensors and systems for water and air purification. Among the diversity of purification approaches, photocatalysis is viewed as a particularly promising method. Considering various potential materials, titanium dioxide stands out due to its physicochemical properties. Reactive magnetron sputtering is considered one of most effective techniques for titanium dioxide deposition.

Aim. To investigate the influence of synthesis parameters on the efficiency of a TiO2-based photocatalyst for its further application in water purification and gas sensing.

Materials and methods. Two series of five samples each were manufactured. In the first series, the sputtering duration was varied (3, 7, 10, 15, 30 min). In the second series, the argon-to-oxygen ratio in the reactive mixture was varied (90/10, 70/30, 50/50, 30/70, 10/90%). Subsequently, all samples in both series were irradiated for 2 h and then evaluated for hydrophilicity using an OSA 15 EC device.

Results. Two dependencies, i.e., the contact angle as a function of sputtering duration and the contact angle as a function of oxygen content in the reactive mixture, were established. The employed method was found to be suitable for depositing photocatalytic titanium dioxide films. Upon an increase in film thickness, the contact angle index varies within 37 and 45º. A 10-fold increase in sputtering duration (from 3 to 30 min) caused no significant differences in the photocatalytic and hydrophilic properties of the samples. It was experimentally established that the most photoactive films are synthesized at Ar/O2 ratios of 90/10 and 10/90%.

Conclusion. The developed photocatalytic titanium dioxide film can be recommended for a number of water purification tasks and for use in gas sensors.

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