The electrochemical properties of carbon were improved by forming composites with Ni-doped CeO₂ nanoparticles to obtain a material with potential for application in high performance energy storage devices. Composites of Ni-doped CeO₂ (Ce_1-xNi_xO₂, x = 0, 0.05, 0.10 and 0.20) nanoparticles were formed with carbon by hydrothermal treatment at a temperature of 150 °C for 12 h, hitherto referred to as carbon/CeO₂, carbon/5Ni

CeO₂, carbon/10NiCeO₂ and carbon/20NiCeO₂ for x = 0, 0.05, 0.10 and 0.20, respectively. CeO₂ nanoparticles without carbon were also prepared by the same method for comparison. All samples were characterized by X-ray diffraction (XRD), Raman spectroscopy (Raman), energy dispersive X-ray spectroscopy (EDX), field emission scanning electron microscopy (FESEM) - elemental mapping, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET) and a potentiostat/galvanostat electrochemical cell system. The samples exhibited XRD and Raman peaks corresponding to carbon and FCC CeO₂, confirming the formation of composites. The presence of Ce⁴⁺, Ce³⁺/oxygen vacancies and Ni²⁺ in all composites was confirmed by XPS measurements. The specific capacitances at a current density of 0.25 A/g were in the range of 138.8–252.6 F/g for electrodes made from carbon/Ni-doped CeO₂, which were higher than that of CeO₂ (11.9 F/g) and carbon (64.1 F/g) alone. These results suggest that composites of Ni-doped CeO₂ nanoparticles with carbon have improved capacitive behavior as electrodes due to a higher concentration ratio of Ce³⁺/Ce⁴⁺.

中文翻译：

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碳/镍掺杂CeO ₂复合材料的合成，表征和电化学性能

通过与掺Ni的CeO ₂纳米颗粒形成复合材料，可以改善碳的电化学性能，从而获得具有在高性能储能装置中应用潜力的材料。通过在150°C的温度下进行水热处理12 h，用碳形成掺Ni的CeO ₂（Ce _1-x Ni _x O ₂，x = 0、0.05、0.10和0.20）纳米粒子的复合物，迄今称为碳/ CeO ₂，碳/ 5Ni

CeO ₂，碳/ 10NiCeO ₂和碳/ 20Nix的CeO _2分别为0、0.05、0.10和0.20。还通过相同的方法制备了不含碳的CeO ₂纳米颗粒用于比较。所有样品的特征均通过X射线衍射（XRD），拉曼光谱（Raman），能量色散X射线光谱（EDX），场发射扫描电子显微镜（FESEM）-元素图谱，透射电子显微镜（TEM），X-射线光电子能谱（XPS），布鲁瑙尔-埃米特-泰勒（BET）和恒电位仪/恒电流仪电化学池系统。样品表现出对应于碳和FCC CeO _2的XRD和拉曼峰，证实了复合物的形成。Ce ⁴⁺，Ce ³⁺ /氧空位和Ni ^2+的存在XPS测量证实了所有复合材料中的含量。由碳/镍掺杂的CeO ₂制成的电极在0.25 A / g的电流密度下的比电容在138.8–252.6 F / g的范围内，高于CeO ₂（11.9 F / g）和碳（64.1 F / g）。这些结果表明，由于较高的Ce ³⁺ / Ce ^4+的浓度比，具有碳的Ni掺杂的CeO ₂纳米颗粒的复合物具有改善的电极电容性能。