ZIF-8衍生氮掺杂多孔炭吸附剂的制备及对罗丹明B吸附性能的研究

Preparation of N-doped Carbons from ZIF-8 and Adsorptive Removal of Rhodamine B from Water

因孔径结构和氮掺杂的协同效应,氮掺杂多孔炭质吸附剂在吸附处理染料污染物方面备受关注。本文在低温水热处理葡萄糖的基础上,原位合成了葡萄糖@ZIF-8复合物,1000℃下直接高温碳化,得到了不同氮配位环境的多孔炭材料。研究发现,包覆的半聚合葡萄糖在碳化时可抑制ZIF-8中氮物种的逸出程度,使得炭质吸附剂具有较高的氮掺杂浓度和优异的罗丹明B(RhB)吸附性能。吸附动力学结果表明,25℃时,样品GZC-10在240 min内可吸附饱和,平衡吸附量为283 mg·g^(-1),吸附扩散行为符合伪二级动力学模型。吸附等温线能够很好地符合Langmuir模型,最大吸附量为383 mg·g^(-1),远高于文献报道的同类MOF衍生炭材料。本文制备的氮掺杂多孔炭质吸附剂具有吸附量大、动力学快、润湿性好等优良性能,是一种高效的水处理材料。

N-doped hierarchical porous carbons showed superior performance for dyes removal via adsorption because of the synergetic effects between porous architecture and N-dopants.In this paper,N-doped porous carbons were obtained by direct carbonization of glucose@ZIF-8composite,and the partially polymerized glucose was obtained by the low-temperature hydrothermal treatment of glucose solution,indicating that the presence of glucose outside the surface of ZIF-8 would restrain the loss ofNspecies.As a result,the as-made N-doped carbons included high concentrated N-species and superior removal performance towards Rhodamine B.The kinetics indicated that the as-made GZC-10 sample showed an equilibrium amount of 283 mg/g at 25℃as time up to 240min,according to pseudo-second order model.Langmuir model expressed the better conformity for isotherms with maximum amount of 383 mg/g,much larger than that of other types of MOF-based carbons.All the results indicated that the present carbons were useful for water treatment considering satisfactory performance with high removal capacity,fast kinetic,and good wettability.