巯基修饰的钛酸纳米管吸附汞

摘要

The titanate nanotubes (TNTs) were prepared by alkaline hydrothermal method,and the surface of TNTs were modified by thiol groups through silanization reaction. Characterization with transmission electron microscope and elemental analysis proved that thiol groups were successfully grafted on TNTs. Based on the strong interaction between Hg2+ and thiol groups,thiol groups modified TNTs (TNTs-SH) were applied for re-moval of Hg2+from solution. When the solution pH ranged from 3 to 7,the adsorption capacity showed no obvi-ous variation,indicating that TNTs-SH could remove Hg2+ effectively under acid condition. The maximum ad-sorption capacity calculated by Langmuir equation was 134. 23 mg / g at pH 6. 5,and TNTs-SH still maintained good adsorption capability in high salinity solution. The kinetic study showed that the adsorption of Hg2+ on TNTs-SH fitted well with pseudo-second order kinetic equation,and adsorption rate was quite fast.%采用碱性水热法制备钛酸纳米管,再通过硅烷化反应在其表面修饰巯基.透射电镜和元素分析的表征结果表明巯基被成功的修饰到了钛酸纳米管的表面.基于巯基和 Hg2+之间的“软—软”相亲作用,巯基修饰的钛酸纳米管(TNTs-SH)可用于水体中 Hg2+的去除.在溶液 pH 为3~7的范围内,TNTs-SH 对 Hg2+的吸附没有明显的变化,表明该材料可以在酸性条件下有效的去除 Hg2+.由 Langmuir 吸附等温模型拟合出 Hg2+在TNTs-SH 上的最大吸附量为134．23 mg/ g,并且在较高的离子强度下,仍然保持了较高的吸附量.动力学研究表明 Hg2+在 TNTs-SH 上的吸附过程符合二级反应动力学方程,吸附速率较快.