本研究的目的有二，第一是調整次微米級二氧化鈰中空球的缺陷分布，第二是探討此種結構的物理特性。在缺陷分布的控制上，利用與檸檬酸進行水熱反應，在其上形成碳膜以及在殼層中形成碳摻雜。由X光繞射分析(XRD)、穿透式電子顯微鏡(TEM)、顯微拉曼光譜儀(Raman)以及X光吸收光譜(XAS)的分析結果指出當反應時間高於4小時，除了在中空球表面觀察到有非晶碳層形成，在殼層內部亦發現碳取代氧反應深度可達5nm，此種取代形成電荷轉移，使Ce3+的含量由7%上升至高達50%。
在磁性分析上，經由水熱法改質的二氧化鈰中空球於室溫下之鐵磁性皆比原始中空球高，飽和磁化量的提升可達5倍。結合結構分析可推測在中空球結構中將缺陷層的厚度增加對磁性的提升並沒有明顯的幫助，磁性形成的關鍵仍在於中空球的表層。
最後以循環伏安法量測CeO2(A)以及C@CeO2(A)-5hrs的電化學性質，實驗結果皆沒有出現氧化還原峰，利用CV曲線換算比電容發現兩樣品的數值並沒有明顯差異且與文獻相比皆較差，推測原因在於碳取代殼層表層的氧之缺陷無法為電化學性質帶來提升。

The purpose of this research is twofold. The first is to adjust the defect distribution of sub-micron ceria hollow spheres, and the second is to explore the physical properties of this structure. In the control of defect distribution, the hydrothermal reaction with citric acid is used to form a carbon film thereon and a carbon dopant in the shell layer. The analysis results of X-ray diffraction analysis (XRD), transmission electron microscope (TEM), Micro-Raman spectrometer (Raman), and X-ray absorption spectroscopy (XAS) indicate that the reaction time is higher than 4 hours, except in hollow spheres. A carbon layer is formed on the surface, and the carbon simultaneously replaces the oxygen with a thickness of 5nm on the surface of the shell layer to form a charge transfer, which increases the content of Ce3+ from 7% to as high as 50%.
In terms of magnetic analysis, the room temperature ferromagnetism of the ceria hollow spheres modified by the hydrothermal method is higher than that of the original hollow spheres, and the saturation magnetization can be increased by up to 5 times. Combined with structural analysis, it can be inferred that expanding the distribution range of defects in the hollow sphere structure cannot effectively improve the magnetic properties, and the key lies in the surface.
Finally, the electrochemical properties of CeO2(A) and C@CeO2(A)-5hrs were measured by cyclic voltammetry. The experimental results showed no redox peaks. Using the CV curve to convert the specific capacitance, it was found that the values of the two samples were not significantly different. After comparing with the literature, they were inferior. It is speculated that the reason is that the defects of the carbon-substituted shell in the surface layer cannot improve the electrochemical properties.

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