In the present study, graphene (rGO) hydrogel was fabricated by reducing graphene oxide (GO) with ascorbic acid to remove U(VI) from aqueous solution. The resulting rGO hydrogel shows a 3D porous network structure and good mechanical stability. The effect of contact time, pH, and initial U(VI) concentration on U(VI) adsorption, as well as the reusability of the material were estimated with batch experiments. The results illustrate that U(VI) adsorption on rGO hydrogel agreed well with pseudo-second order kinetic model, indicating a chemical adsorption. According to correlation coefficients, Freundlich model is the most suitable isothermal model to describe the U(VI) adsorption process of rGO hydrogel, with a maximum adsorption capacity of 134.23 mg/g (pH 4.0). The solution pH posed significant influence on U(VI) adsorption: the adsorption amount rises sharply from pH 2.0 to 4.6, reaches a plateau at 4.6–6.5, and then declines slightly at pH levels above 6.5. The rGO hydrogel shows good reusability, with maintaining 94.76% adsorption ability after ten adsorption/desorption cycles, demonstrating that rGO hydrogel is a promising adsorbent for U(VI) removal from aqueous solution, providing a new insight for the developing of U(VI) adsorbents.

在本研究中，通过用抗坏血酸还原氧化石墨烯（GO）从水溶液中去除U（VI）来制造石墨烯（rGO）水凝胶。所得的rGO水凝胶显示出3D多孔网络结构和良好的机械稳定性。通过批处理实验评估了接触时间，pH和初始U（VI）浓度对U（VI）吸附的影响以及材料的可重复使用性。结果表明，U（VI）在rGO水凝胶上的吸附与拟二级动力学模型吻合得很好，表明了化学吸附。根据相关系数，Freundlich模型是描述rGO水凝胶的U（VI）吸附过程的最合适的等温模型，最大吸附容量为134.23 mg / g（pH 4.0）。溶液的pH值对U（VI）的吸附有重要影响：吸附量从pH 2.0急剧上升至4.6，在4.6-6.5达到平稳，然后在pH高于6.5时略有下降。rGO水凝胶显示出良好的可重用性，在十次吸附/解吸循环后保持94.76％的吸附能力，证明rGO水凝胶是从水溶液中去除U（VI）的有希望的吸附剂，为U（VI）的开发提供了新的见识吸附剂。