高性能的MOF/carbon复合材料对水溶液中铀酰的吸附

High Performance of MOF/Carbon Composites for U(Ⅵ) Adsorption From Aqueous Solution

通过水热法和煅烧处理合成了金属有机框架/碳(MOF/carbon),并用作吸附剂吸附水溶液中的 U(Ⅵ)。研究了MOF/carbon在不同的pH、初始 U(Ⅵ)浓度、反应时间下的吸附实验。结果表明:MOF/carbon对 U(Ⅵ)的吸附能力远远高于单纯的MOF和碳,这主要归因于MOF/carbon丰富的表面吸附位点和MOF/ carbon 与 U(Ⅵ)之间极强的静电吸引作用。基于Zeta和X射线光电子能谱分析发现,表面络合和静电作用可以为MOF/carbon吸附 U(Ⅵ)提供一个非常合理的解释。热力学实验表明, U(Ⅵ)的去除是一个自发和吸热过程。此外,吸附动力学实验结果表明: U(Ⅵ)的吸附是一个快速并且高效的过程。这一发现为废水中 U(Ⅵ)的消除和环境修复提供了一种高效吸附剂。

MOF/carbon was successfully synthesized by hydrothermal method and calcining treatment, and used as an adsorbent to remove U(Ⅵ) from aqueous solution. The adsorption behavour of U(Ⅵ) on MOF/carbon were studied at different pH values, initial U(Ⅵ) concentrations, and reaction time. The experimental results show that the adsorption capacity of MOF/carbon towards U(Ⅵ) is much higher than that of pure MOF and carbon, which is mainly attributed to abundant adsorption sites on the surface and strong electrostatic attraction between the surface of MOF/carbon and U(Ⅵ). Based on Zeta potential and X-ray photoelectron energy spectrum analysis, it is found that the surface complexation and electrostatic action can provide a very reasonable explanation for U(Ⅵ) removal. Thermodynamic experiments indicate that the removal of U(Ⅵ) is a spontaneous and endothermic process. In addition, the adsorption kinetic experiments show that the adsorption of U(Ⅵ) is a fast and efficient process. The results provide a highly effective adsorbent for the elimination and environmental remediation of U(Ⅵ) from wastewater.