Nanostructured thin films of titanium dioxide by RF Magnetron Sputtering

Titanium dioxide has kept a great interest in the last years among the various photocatalyst semiconductors thanks to the wide range of potential applications: photovoltaic energy productions1, hydrogen production by water splitting2, photocathodic protections of metals3, photodegradation of organics and inorganic pollutants4. In this work, some results will be reported on the achievement of undoped and nitrogen-doped anatase and anatase/rutile thin films, deposited by RF magnetron sputtering in reactive atmosphere from a Ti target (99,9% purity). To tune the titanium dioxide thin film phases, RF power and pressures of gas inlets in the deposition chamber together with the sample temperature and sample-holder motion were carefully adjusted during the deposition process. In this way nanostructured thin films were deposited with the selected allotropic structure, as shown by XRD analysis. The stoichiometry of the doped samples was monitored by XPS analysis. The SEM characterization showed the influence of sample-holder motion on the shape and the dimensions of the film surface morphology. The photoactivity of films deposited on two different conducting supports (ITO and Ti/glass) was investigated by means of Electrochemical Impedance Spectroscopy (EIS) and Cyclic Voltammetry (CV), Chronoamperometry (CA) and Chronopotentiometry (CE). Moreover, BTEX photodegradation measurements were performed using a mixed flow reactor5.