This study successfully synthesized a novel photocatalyst, a composite of silicon carbide and graphitic carbon nitride, which achieved efficient photocatalytic reduction of uranium (VI) under visible light irradiation. The optimal loading of silicon carbide in the composite was determined to be SiC15@g-C3N4, which significantly enhanced the optoelectronic properties of graphitic carbon nitride, improving the separation efficiency of photogenerated electron-hole pairs and extending the electron lifetime from 1.73 ns to 3.96 ns. Furthermore, the adding of silicon carbide effectively modified the band structure of graphitic carbon nitride, with the conduction band position shifting from −0.74 eV to −1.18 eV, thereby enhancing the reducibility. In photocatalytic reduction experiments, the SiC15@g-C3N4 composite demonstrated exceptional reduction efficiency, achieving a remarkable 100 % photocatalytic reduction rate within 30 min, which is significantly superior to that of pristine g-C3N4. The study revealed that superoxide radicals (·O2-) are the main reactive species in the reaction, leading to the formation of uraninite (UO2) as the reduced product. These findings not only deepen the understanding of the synergistic effects between SiC and g-C3N4 but also provide new perspectives for the design of efficient photocatalysts. The SiC15@g-C3N4 composite shows potential applications in environmental remediation and nuclear waste management.

中文翻译：

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碳化硅-石墨氮化碳复合材料的简便原位合成，用于增强光催化铀 （VI） 回收率


本研究成功合成了一种新型光催化剂，一种碳化硅和石墨氮化碳的复合材料，在可见光照射下实现了对铀 （VI） 的高效光催化还原。确定复合材料中碳化硅的最佳负载量为 SiC15@g-C3N4，这显着增强了石墨氮化碳的光电性能，提高了光生电子-空穴对的分离效率，并将电子寿命从 1.73 ns 延长到 3.96 ns。此外，碳化硅的加入有效地改变了石墨氮化碳的能带结构，导带位置从 -0.74 eV 移动到 -1.18 eV，从而提高了可还原性。在光催化还原实验中，SiC15@g-C3N4 复合材料表现出优异的还原效率，在 30 分钟内实现了显著的 100% 光催化还原率，明显优于原始的 g-C3N4。研究表明，超氧自由基 （·O2-） 是反应中的主要反应性物质，导致形成铀酸盐 （UO2） 作为还原产物。这些发现不仅加深了对 SiC 和 g-C3N4 之间协同效应的理解，也为高效光催化剂的设计提供了新的视角。SiC15@g-C3N4 复合材料在环境修复和核废料管理方面显示出潜在的应用。