Synthesis of mesoporous Au-doped TiO2 using one-step holvothermal method for photocatalytic degradation of paracetamol

• Main Authors: Meng-Fan Tsai, 蔡夢帆
• Other Authors: Chin-Jung Lin
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/62164236823936660670

碩士 === 國立宜蘭大學 === 環境工程學系碩士班 === 103 === The Au-doped TiO2 hollow-microspheres (Au/TMS) were fabricated using one step template-free method under microwave irradiation. One step synthesis method is a kind of high efficiency process of preparation of materials. Because of saving time, reducing the use of chemicals and low cost, it’s the friendly environmental materials. The obtained material with high photocatalytic activity can degrade paracetamol completely under visible light and enhance the photocatalytic efficiency by mesoporous hollow spherical structure with enhancing the surface area and Au doped TiO2 enhance the electron transfer rate. The morphology and microstructure of the obtained materials were characterized by Field Emission Scanning Electron Microscope (FESEM) and High Resolution Transmission Electron Microscope (HRTEM). The characteristic of materials was analyzed by X-ray Diffractometer (XRD), Electron Spectroscopy for Chemical AnalysisElectron Spectroscopy for Chemical Analysis (ESCA), X-ray absorption spectroscopy (XAS) and BET. In this study, XRD patterns show that the synthesis of mesoporous Au-doped TiO2 hollow-microspheres materials is anatase TiO2. Measured TMS, 0.25Au / TMS, 0.5Au / TMS, 1.0Au / TMS specific surface areais 56, 79, 61, 172 m2 / g respectively, by BET. Mesoporous Au / TiO2 hollow spheres material is visible catalyst by UV-Vis evaluation. By CO chemisorption experiments, observed Au exposed area in the mesoporous Au/TiO2 hollow spheres materials is 2.261×10-1, 3.753×10-1, 2.371×10-1 m2 respectively. Analyzed characteristics of Au and TiO2 of mesoporous Au/TiO2 is hollow spheres materials via the XAS. By photocatalytic degradation of paracetamol experiments, analyzed photocatalytic activity of TMS, Au-0.1/TMS, Au-0.25/TMS, Au-0.5/TMS, Au-1.0/TMS, the first-order kinetics constant K value; according to Au content from low to high is 7.993 × 10-3, 7.933 × 10-3, 14.694 × 10-3, 8.313 × 10-3, 1.883 × 10-3 respectively. Through Au doping photocatalytic activity is enhanced to double. Through 10 repeat photocatalytic experimentation analyzed light-decay of mesoporous Au / TiO2 hollow microspheres materials; after 50 hours continuous photocatalysis and continuous monitoring, assessment of mesoporous Au / TiO2 hollow microspheres materials is no significant light-decay. In this study, theprepared method is successfully established about synthesizing Au/ TiO2 hollow-microspheres within 2 hours by one step microwave-assisted synthesis method. The obtained material is chemical stability to avoid light-decay in photocatalysis. By carring out one step template-free method with microwave, it can reduce the reaction time, reduce the reaction temperature, improve production efficiency and reduce the difficulty of preparing. Generating plasma resonance effect, it can improve the photocatalytic TiO2 in reaction activity, enhanced the efficiency of material removal of contaminants in water by doping Au.One step template-free method of simplicity and timeliness will benefit to produce visible light photocatalytic decomposition of environmental pollutants. These are prerequisites of practical application in environment due to simple operation, easy preparation, quick production, low cost, reuse ability and friendly environment.