Abstract:

In order to adsorb Hg²⁺ in waste water efficiently and quickly, copper-based metal organic frameworks (Cu-MOFs) were prepared using electrochemical method and modified by ethanedithiol to deposit sulfhydryl on it. The SH-Cu-BDC materials obtained were used for adsorbing Hg²⁺ in waste water. The samples modified before and after were characterized with EDS, IR, N₂ adsorption, SEM. The results show that: -SH groups have been connected to the surface of Cu-BDC materials; the modified SH-Cu-BDC materials have micro-porous structure and large specific surface area as well as unique flower structure and evenly distribute antenna shape matter. 10 mg SH-Cu-BDC can absorb about 20 ml Hg²⁺ solution (300 mg·L^-1) at pH=5. The adsorption reaches saturation after 60 min and the maximum capacity (saturated adsorption capacity) is about 585 mg·g^-1. The adsorption of Hg²⁺ on SH-Cu-BDC is monolayer and follows quasi-second-order kinetics and Langmuir adsorption isotherm. Regeneration experiment shows that SH-Cu-BDC may reuse.

Key words: electrochemistry, synthesis, MOFs, -SH, modification, adsorbent, Hg²⁺

摘要：

为高效对废水中的Hg²⁺进行吸附，采用电化学法合成Cu-BDC金属有机骨架材料，并进行-SH修饰，制备SH-Cu-BDC材料，用于对含Hg²⁺废水的吸附研究。通过EDS与IR红外对修饰前后样品的表征分析可知，-SH基团成功修饰到Cu-BDC材料上；N₂吸附实验表明，修饰后的SH-Cu-BDC材料出现微孔结构且比表面积增大；SEM分析表明，电化学合成Cu-BDC材料具有独特花状结构，修饰后SH-Cu-BDC材料表面均匀分布着触角状物质；10 mg SH-Cu-BDC对20 ml浓度为300 mg·L^-1的Hg²⁺溶液进行吸附，当pH=5，60 min时吸附饱和，最大吸附量为585 mg·g^-1；SH-Cu-BDC材料对Hg²⁺的吸附符合拟二级反应动力学方程和Langmuir吸附等温模型，该吸附过程是以表面吸附为主的扩散过程，且符合单分子层吸附规律；吸附再生实验表明，SH-Cu-BDC作为吸附剂可重复使用，且具有一定的稳定性。

关键词: 电化学, 合成, 金属有机骨架材料, 巯基, 修饰, 吸附剂, Hg²⁺