本研究探討摻雜鈰元素之碳量子點(Ce-CQDs)對二氧化鈦(TiO2)光催化性能的調控。首先，通過調整六水硝酸鈰前驅物並製備五種不同摻雜濃度的Ce-CQDs，並利用感應耦合電漿質譜儀(ICP-MS)對摻雜元素之濃度進行分析；結果顯示，隨著前驅物濃度的增加，鈰元素於碳量子點中之濃度也逐漸升高。接著透過X射線繞射(XRD)分析、傅立葉轉換紅外光譜(FT-IR)分析、穿透式電子顯微鏡(TEM)影像分析以及X射線吸收光譜(XAS)等方法，探討各樣品之結構與性質；隨後，將Ce-CQDs與TiO2混合製備複合材料TiO2/Ce-CQDs，並在模擬太陽光下進行甲基橙(Methyl orange, MO)染劑的降解實驗。實驗結果顯示，Ce-CQDs可以 提升TiO2之光吸收範圍並提升光催化降解效率；此外，透過紫外光電子能譜(UPS)和低能量反光電子能譜(LEIPS)分析確認價帶和導帶位置，並推測其光催化降解機制。結果表明，摻雜鈰元素能提供碳量子點更多的電子，增強其電子轉移能力，從而提升複合材料的光催化降解效率。

This study investigates the modulation of photocatalytic performance of titanium dioxide (TiO2) by cerium-doped carbon quantum dots (Ce-CQDs). Initially, five different concentrations of Ce-CQDs were prepared by varying the amount of cerium nitrate hexahydrate precursor, and their elemental concentrations were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). The results indicated that the cerium concentration in the carbon quantum dots increased with the precursor concentration. Subsequently, the structures and properties of the samples were characterized using X-ray diffraction (XRD) analysis, Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM) imaging, and X-ray absorption spectroscopy (XAS). The results showed that the cerium-doped carbon quantum dots did not form new crystalline phases, and their optical properties changed with the increase in cerium concentration. Next, Ce-CQDs were mixed with TiO2 to prepare composite materials (TiO2/Ce-CQDs), and degradation experiments on methyl orange (MO) dye were conducted under simulated sunlight. The results indicated that cerium doping provides more electrons to the carbon quantum dots, enhancing their electron transfer capability, thereby improving the photocatalytic degradation efficiency of the composite material. Moreover, the valence and conduction band positions of the samples were determined using ultraviolet photoelectron spectroscopy (UPS) and low energy inverse photoemission spectroscopy (LEIPS), and the photocatalytic degradation mechanism was inferred. In summary, this study demonstrates that cerium-doped carbon quantum dots can significantly enhance the photocatalytic performance of titanium dioxide, providing an effective method for modifying photocatalytic materials. Comprehensive characterization using various analytical instruments verified the effect of cerium doping on the optical and chemical properties of carbon quantum dots, and the experimental results confirmed their potential in photocatalytic degradation applications.

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