| 초록 |
Titanium is one of the most researched material due to it physical and chemical property and used in many application field such as photocatalyst, transparent conducting oxide, dye sensitized solar cell and etc. Especially in photocatalytic area, it has been extensively studied as powerful organic decomposing material. Generally, TiO2 nanoparticles are synthesized through sol-gel, hydrothermal and precipitation methods. However, these methods need to precisely control solution pH, temperature with long reaction time and after that, washing organic compounds and drying process is essential. To overcome these disadvantages, plasma electrolytic oxidation method was adopted. This method was originally used to produce thick and durable oxide layer on the easy-corrosive metal surface to prevent from corrosion in air ambient using small amount of electrolyte and short reaction time. By controlling experimental conditions, amorphous TiO2 nanoparticles could be synthesized. Changing the experimental condition such as electrolyte concentration, nanoparticle size could be controlled between 16 and 28 nm with uniform size distribution. To analyze photocatalytic property depending on the structure, produced amorphous TiO2 was transformed into anatase, rutile and mixed phase through different calcination temperature. Photocatalytic efficiency was measured by decomposing methylene blue organic dye solution with 300 W xenon lamp. The calcination condition of 500oC with anatase and rutile mixed phase showed best degradation property following the synergetic effect between two different band gap structures. We believe that this new TiO2 nanoparticle synthesis method would contribute to the industrial field with high quality and mass production. |
