There is a need to develop highly efficient materials for capturing uranium from nuclear wastewater. Here, 5-methylbenzotriazole modified graphene oxide (MBTA-GO) was used to adsorb U(VI) from aqueous solution. By the trials of different conditions, we found that the removal of U(VI) from acidic solution was strongly dependent on pH but independent of ionic strength. The U(VI) adsorption was perfectly conformed to the pseudo-second-order kinetics and the adsorption isotherms were simulated by the Langmuir model well. A high removal capacity (q_max = 264 mg/g) for U(VI) at pH 3.5 was obtained. XPS, EXAFS analyses and DFT calculations revealed that the mechanism of uranium capture was ascribed to (i) the surface complexation by benzotriazole and carboxyl groups (providing lone pair electrons) on MBTA-GO and (ii) enhanced synergistic coordination ability of delocalized π-bond of triazole group toward U due to the transfer of electrons from graphene sheet to benzotriazole. DFT calculations further demonstrated that benzotriazole displayed stronger binding with U(VI) compared to carboxyl group due to higher binding energy of [Side/Surface-U-MBTA-GO] (79.745, 54.986 kcal/mol) than [MBTA-GO–COOH–U] (27.131 kcal/mol). This work will provide valuable insight into designing novel nitrogen-containing adsorbents for practical application in wastewater treatment.

需要开发用于从核废水中捕获铀的高效材料。在这里，使用5-甲基苯并三唑改性的氧化石墨烯（MBTA-GO）从水溶液中吸附U（VI）。通过不同条件的试验，我们发现从酸性溶液中去除U（VI）强烈取决于pH值，但与离子强度无关。U（VI）吸附完全符合拟二级动力学，并且通过Langmuir模型很好地模拟了吸附等温线。高去除能力（_最大q 对于pH为3.5的U（VI）获得了264 mg / g（= 264 mg / g）。XPS，EXAFS分析和DFT计算表明，铀捕获的机理归因于（i）MBTA-GO上苯并三唑和羧基的表面络合（提供孤对电子），以及（ii）增强了离域π-的协同配位能力。由于电子从石墨烯片转移到苯并三唑，三唑基团向U的键合。DFT计算进一步证明，与[MB / GO-COOH]相比，[Side / Surface-U-MBTA-GO]的结合能更高（79.745，54.986 kcal / mol），苯并三唑与U（VI）的结合力强于羧基。 –U]（27.131 kcal / mol）。这项工作将为设计用于废水处理的新型含氮吸附剂提供有价值的见识。