Nitrogen enrichment and increased nitrogen content is an effective strategy for enhancing adsorp-tion of uranium by carbon nitride polymers.Herein,we reported the uranium absorption by us-ing a structurally well-defined and nitrogen-rich carbon nitride polymer with C3N5 stoichiome-try for the first time.In comparison with the adsorption performance of g-C3N4 for U(Ⅵ),the conjugation system of the material was increased by connecting the heptazine unit through the azo bridge in the structure of C3N5,so that C3N5 exhibited several times higher adsorption per-formance than that of g-C3N4.The C3N5 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 max-imum adsorption capacity is 207 mg/g,meanwhile,the material exhibits high selectivity.The results of spectral analysis and theoretical calculations indicate that the process of uranyl ion capture by C3N5 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 C3N5.This work indicates that C3N5 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 nitrogen-rich carbon nitrogen polymers on uranyl ions.

Zeru Wang;Wenhao Li;Linzhen Wu;Zhuang Wang;Yalan Cao;Jingkai Cheng;Guangyuan Chen;Qian Zhao;Mei Jiang;Zhengguo Chen;Lin Zhu;Tao Duan

National Co-Innovation Center for Nuclear Waste Disposal and Environmental Safety,Southwest University of Science and Technology,Mianyang 621010,China;State Key Laboratory of Environment-friendly Energy Materials,School of National Defence Science and Technology,Southwest University of Science and Technology,Mianyang 621010,China;College of Chemistry,Sichuan University,Chengdu 610064,China;School of Physics and Astronomy,China West Normal University,Nanchong 637002,China;NHC Key Laboratory of Nuclear Technology Medical Transformation,Mianyang Central Hospital,Mianyang 621010,China

中国化学快报（英文版）

[1]Zeru Wang;Wenhao Li;Linzhen Wu;Zhuang Wang;Yalan Cao;Jingkai Cheng;Guangyuan Chen;Qian Zhao;Mei Jiang;Zhengguo Chen;Lin Zhu;Tao Duan-.Nitrogen-rich carbon nitrogen polymers for enhancing the sorption of uranyl)[J].中国化学快报（英文版）,2022(07):3468-3473

stoichiome

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