Process Control and Study of Magnetism and SERS of Hollow Cerium Oxide Spheres

• Main Authors: Yuan-Ching Tsai, 蔡元景
• Other Authors: Shih-Yun Chen
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/b5q35b

碩士 === 國立臺灣科技大學 === 材料科學與工程系 === 106 === In this study, all the sample was prepared by two-step process. Firstly, Hollow CeO2 spheres were synthesized by spray pyrolysis (SP) process. The deposition of Ag nanoparticles (NPs) on CeO2 sphere surface was followed via incipient wetness method. X-ray diffraction (XRD), transmission electron microscopy (TEM), X-rays absorption spectroscopy (XAS) and Raman spectroscopy were utilized to investigate the components, morphology, valence state of cations and defect structure. Raman spectrometer and vibrating sample magnetometer (VSM) was utilized to measure surface-enhanced Raman scattering (SERS) and magnetic behavior at room temperature (RT), respectively. TEM was utilized to observe Ag nanoparticles deposition on the different sample surface. Both of the size of Ag NPs and its coverage on CeO2 sphere were influenced by doping concentration and CeO2 particle size, and a further consequence to SERS effect. XAS analysis and Raman predicted that Ce3+ ratio and oxygen vacancy were increased after depositing Ag NPs. Moreover, All (H)CeO2-Ag composites were ferromagnetic at RT. Notably, the Ms value were impacted on the method of the calcined sample.