Nitrogen-rich carbon nitrogen polymers for enhancing the sorption of uranyl
Nitrogen-rich carbon nitrogen polymers for enhancing the sorption of uranyl
复制标题
用于增强铀酰吸附的富氮碳氮聚合物
DOI：
10.1016/j.cclet.2022.03.097
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发表时间：
2022
影响因子：
9.1
通讯作者：
Duan Tao
中科院分区：
文献类型：
--
作者：
Wang Zeru;Li Wenhao;Wu Linzhen;Wang Zhuang;Cao Yalan;Cheng Jingkai;Chen Guangyuan;Zhao Qian;Jiang Mei;Chen Zhengguo;Zhu Lin;Duan Tao
富氮和增加氮含量是提高氮化碳聚合物对铀的吸附的有效策略。在这里，我们首次报道了一种结构明确的富氮碳氮化物聚合物，其化学计量比为C_3N_5。与g-C_3N_4对U(VI)的吸附性能相比，C_3N_5通过偶氮桥连接七嗪单元增加了材料的共轭体系，使C_3N_5表现出比g-C_3N_4高几倍的吸附性能。C_3N_5对铀酰离子具有较高的吸附动力学，仅需10min即可吸附100 mg/g U(VI)，60min即可达到完全吸附平衡，理论最大吸附容量为207 mg/g，同时具有较高的选择性。光谱分析和理论计算结果表明，C_3N_5捕获铀酰离子的过程是物理吸附和化学吸附相结合的过程，其较高的电子态密度使其静电结合能力增强，有利于C_3N_5对铀酰离子的吸附。这表明C_3N_5在铀酰离子的分离和富集化方面具有广阔的应用前景，也为系统研究富氮碳氮聚合物对铀酰离子的吸附能力提供了参考。
Nitrogen enrichment and increased nitrogen content is an effective strategy for enhancing adsorption of uranium by carbon nitride polymers. Herein, we reported the uranium absorption by using a structurally well-defined and nitrogen-rich carbon nitride polymer with C_3N_5 stoichiometry for the first time. In comparison with the adsorption performance of g-C_3N_4 for U(VI), the conjugation system of the material was increased by connecting the heptazine unit through the azo bridge in the structure of C_3N_5, so that C_3N_5 exhibited several times higher adsorption performance than that of g-C_3N_4. The C_3N_5 has high kinetics for uranyl ions, which can adsorb 100mg/g U(VI) in only 10 min and reach complete adsorption equilibrium in 60 min; the theoretical maximum adsorption capacity is 207mg/g, meanwhile, the material exhibits high selectivity. The results of spectral analysis and theoretical calculations indicate that the process of uranyl ion capture by C_3N_5 is a combination of physical and chemical adsorption, and its higher density of electronic states makes the electrostatic binding ability enhanced, which is favorable to the adsorption of uranyl ions by C_3N_5. This work indicates that C_3N_5 has great promise and application in the separation and enrichment of uranyl ions, and also provides a reference for the systematic investigation of the adsorption ability of nitrogenrich carbon nitrogen polymers on uranyl ions.