Preparation of N Doped Indium Titanium Composite and the Evaluation of Photocatalytic Properties

• Main Authors: Chih-Hao Lai, 賴志豪
• Other Authors: Chung-Hsin Wu
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/12484182030343658954

碩士 === 國立高雄應用科技大學 === 化學工程與材料工程系博碩士班 === 101 === This study synthesized indium titanium composite (TiO2-In2O3) nanoparticles via sol-gel method. TiO2-In2O3 was modified by urea and TiO2-In2O3/N was formed. The decolorization percentage of C.I. Reactive Red 2 (RR2) was used to determine the photocatalytic activity of TiO2-In2O3 and TiO2-In2O3/N systems. The prepared photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) specific surface area analysis, UV–vis spectroscopy (UV–vis), zeta potential, thermal gravity analysis (TGA) and X-ray photoelectron spectroscopy (XPS). The effects of the Ti/In ratio, Ti/N ratio, calcination temperature, photocatalyst dose, RR2 concentration and light wavelength on RR2 decolorization by TiO2-In2O3 and TiO2-In2O3/N were evaluated. The phases of prepared photocatalysts were mainly rutile. Further, the lower Ti/In ratio in TiO2-In2O3 generated the higher anatase phase percentage. Compared with undoped TiO2-In2O3, spectra show that the absorption edge shifted to a longer wavelength after N doping. Adding urea reduced the surface area of the photocatalyst and increased the size of indium titania composite particles. The XPS characterization confirmed the Ti-O and In-O in the TiO2-In2O3 and TiO2-In2O3/N systems and in the TiO2-In2O3/N forming the Ti-N-O. The pyrolysis temperature of TiO2-In2O3/N was 753 K and the molar ratio N/Ti was determined as 0.35. The isoelectric point of TiO2, In2O3, TiO2-In2O3 and TiO2-In2O3/N was 4.74, 6.54, 4.90 and 4.75, respectively. The RR2 decolorization efficiency followed the order of 254 nm > 410 nm in all tested systems. Moreover, the RR2 decolorization rate reduced as RR2 concentration increased; conversely, RR2 decolorization rate increased as the photocatalyst dose increased. The TiO2-In2O3 and TiO2-In2O3/N was photoexcited by UV and visible-light irradiation; however, TiO2-In2O3 was only photoexcited by UV irradiation. The efficiency of TiO2-In2O3/N was better than TiO2-In2O3.