Preparation the Au/CeO2 Nanoparticles and its Catalyst Properties

• Main Authors: Yu-Tong Hsiao, 蕭宇棠
• Other Authors: Wei Pan
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/62320407407273392936

碩士 === 國立中正大學 === 物理學系暨研究所 === 101 === The CeO2 has unique physical and chemical properties according to the type of crystalline which may lead to different applications. In this study the hydrothermal method for the synthesis of CeO2 was employed because it is simple and high production yield. Optimal dose of urea and temperature were determined and amino acids were used as additives for synthesis. Shell to core of Au / CeO2 was also performed using the same process. The efficiency of products were tested by the catalytic reaction of 4-nitrophenol. X-ray diffraction (XRD) analysis showed CeO2 was synthesized according to the database (JCPDS-ICDD 1999). However, Au nanoparticle might be too small to be visible from the XRD pattern. The solid Uv-Visible analysis of Au/CeO2 samples confirmed that the samples prepared does contain gold nanoparticles with wavelength 520 (nm) of the absorption. Fourier Transform Infrared Spectroscopy (FTIR) analysis showed that there is no functional group after calcinations. The field emission scanning electron microscope (FE-SEM) analysis showed that using of urea 4.5g, heating 12 hours is smaller , and the crystal shape is more complete of morphology. Not added amino acid sample (Ctrl) is needle; while added amino-Valine is granular. Transmission electron microscopy (TEM) analysis revealed that the patterns is echoes with SEM image, and further observed that the sample's internal crystal. The catalytic reaction of 4-nitrophenol demonstrated that Au/CeO2-Ctrl has the best of catalytic activity, indicating that the ceria-coated gold increase the catalytic activity. Also the shape of needle for this crystal could lead to its high catalytic activity.