The removal of actinide (An) and lanthanide (Ln) elements from aqueous solution is a significant strategy for the safe disposal of radioactive wastes. Herein we presented a 5-methylbenzotriazole modified graphene oxide (MBTA-GO) as a novel adsorbent, in which benzotriazole group was used as targeted sorption site bearing strong affinity toward An-Ln (An and Ln) ions for the first time. MBTA-GO was characterized by Fourier transformed infrared spectroscopy (FT-IR), thermal gravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). The effect of pH and initial concentration on combined adsorption of An-Ln were examined, and the results showed that the adsorption of metal ions on MBTA-GO was strongly dependent on pH in multi-cation solution, and MBTA-GO exhibited excellent An-Ln selectivity (selectivity coefficients are more than 99%), overwhelming majority of other reported adsorbents. The cycle experiments revealed that the MBTA-GO exhibited good reusability and structural stability. By density functional theory (DFT) calculation, the binding energy of Cation-MBTA-GO followed the order of Th(IV) > U(VI) > Eu(III) > La(III) > Sr(II) > Cs(I), suggesting that the benzotriazole groups were preferentially responsible for An-Ln ions on MBTA-GO, which is in well agreement with the experimental results. Finally, the mechanism of selective coadsorption was revealed, which is the synergistic effect of chemical complexation and electrostatic interaction.

从水溶液中去除act系元素（An）和镧系元素（Ln）是安全处置放射性废物的重要策略。本文中，我们提出了一种5-甲基苯并三唑改性的氧化石墨烯（MBTA-GO）作为新型吸附剂，其中苯并三唑基团首次用作对An-Ln（An和Ln）离子具有强亲和力的目标吸附位点。MBTA-GO的特征在于傅立叶变换红外光谱（FT-IR），热重分析（TGA）和X射线光电子能谱（XPS）。研究了pH和初始浓度对An-Ln联合吸附的影响，结果表明MBTA-GO上金属离子的吸附强烈依赖于多阳离子溶液中的pH，MBTA-GO表现出优异的An-Ln Ln选择性（选择性系数大于99％），绝大多数其他报告的吸附剂。循环实验表明，MBTA-GO具有良好的可重用性和结构稳定性。通过密度泛函理论（DFT）计算，阳离子-MBTA-GO的结合能遵循Th（IV）> U（VI）> Eu（III）> La（III）> Sr（II）> Cs（I ），表明苯并三唑基团优先负责MBTA-GO上的An-Ln离子，这与实验结果非常吻合。最后，揭示了选择性共吸附的机理，这是化学络合和静电相互作用的协同作用。Cation-MBTA-GO的结合能遵循Th（IV）> U（VI）> Eu（III）> La（III）> Sr（II）> Cs（I）的顺序，表明苯并三唑基团优先负责MBTA-GO上的An-Ln离子，这与实验结果非常吻合。最后，揭示了选择性共吸附的机理，这是化学络合和静电相互作用的协同作用。Cation-MBTA-GO的结合能遵循Th（IV）> U（VI）> Eu（III）> La（III）> Sr（II）> Cs（I）的顺序，表明苯并三唑基团优先负责MBTA-GO上的An-Ln离子，这与实验结果非常吻合。最后，揭示了选择性共吸附的机理，这是化学络合和静电相互作用的协同作用。