Paper EN-ThP1
N-doped TiO₂ Photocatalytic Thin Films : Synthesis with Controlled Nitrogen Partial Pressure and Study on Their Catalytic Activity

Thursday, October 21, 2010, 6:00 pm, Room Southwest Exhibit Hall

We have deposited N-doped TiOxNy thin films on Si(100) substrates at 500℃ using PEMOCVD method. Titanium iso-propoxide was used as precursor with different nitrogen flow rate to control oxygen and nitrogen contents in the films. Changes of chemical states of constituent elements in the deposited films were examined by XPS analysis. The data showed that with increasing nitrogen flow rate, the total amounts of nitrogen and titanium were increased while that of oxygen was decreased, resulting in a binding energy shift toward high energy side. The characteristics of film growth orientation and structure as well as morphology change behavior were also analyzed by XRD, TED, TEM, AFM, and SEM. Deposition at higher nitrogen flow rate results in finer clusters with a nano-scale grain size and a slower growth rate.

In order to elevate photocatalytic activity of the as-grown N-doped TiOxNy films, argon and oxygen plasmas ignited by atmospheric discharge at 300 W were also used within 5 min. at room temperature. Photocatalytic activity was evaluated by the measurements of the contact angle, UV-Visible spectroscopy. In this work, the effect of the plasma on the improvement of hydrophilic property of N-doped TiOxNy photocatalysts has mainly been investigated. Superhydrophilic property and smooth surface morphology appeared in the UV light irradiation with O₂ plasma treatment.

Keywords : N-doped TiOxNy Thin Film, Photocatalyst, PEMOCVD, Atmospheric Plasma, Surface Modification