Photocatalytic Activity and Visible-Light Response of TiO2 Thin Film Doped with Nitrogen by Using Urea

Abstract

TiO2 has become a widely investigated photocatalyst because of its low cost, low toxicity and high photocatalytic activity under UV irradiation that causes photocatalytic decomposition of organic compounds. Impurities dopant and metal are often used to acquire impurities doped or metal doped TiO2 powder by a sol-gel method. In this paper, we made nitrogen doped TiO2 by a simple process. TiO2 (P25) thin films with 80 % of anatase and 20 % of rutile were fabricated on FTO glass by electrophoretic deposition (EPD). These were then doped with nitrogen by using urea and sintered in electric furnace at 500 and 600 degrees Celsius. EPD was superior for film formation at dispersibility. We calculated absorbance spectra of nitrogen doped TiO2 thin film fabricated on FTO glass. As the result, 600 degrees Celsius is superior sintering temperature at absorbance under visible light than 500 degrees Celsius. Moreover, when the samples sintered at 600 degrees Celsius, each additive amount had different increment of absorbance in specific visible light range. This result indicates the improvement in visible-light response on TiO2 by the simple process. To further research, it is essential to make nitrogen doped TiO2 under pressure and measure the photodegradation reaction.