Adsorbents based on crown ether functionalized composite mesoporous silica for selective extraction of trace silver

作者：Hong, Mingzhu; Wang, Xiu; You, Weijie; Zhuang, Zanyong^*; Yu, Yan^*

来源：Chemical Engineering Journal, 2017, 313: 1278-1287.

DOI：10.1016/j.cej.2016.11.030

• Silver ion
• Mesoporous material
• Crown ether
• Selective adsorption
• Low concentration
• Interfering ions

The selective extraction of trac-level metal ions from unconventional sources such as wastewaters is a long-standing challenge, due to the large concentration difference between the target metal ions and the interfering ions in the matrix. We show here that an adsorbent based on crown ether functionalized mesoporous silica (MS-C-D) overcomes this limitation for selective sequestration of Ag(I) ion. This new adsorbent has hierarchical structure with large specific area and pore framework, which is conducive to the selective adsorption of trace levels of Ag(I) from a complex solution containing concentrated interfered ions such as Cu(II), Zn(II) and Pb(II) ions. The adsorption affinity (b value of 1.45) and selectivity coefficient (distribution coefficient KD of 1.50 *10(5) mL/g) of Ag(I) by using MS-C-D were dramatically higher than many other reported adsorbents (e.g. an Ag(I)-ion-imprinted materials with K-D of 392 mL/ g) in literatures. Furthermore, the lower ion concentration corresponded to higher selectivity for Ag(l). The hierarchically structure of MS-C-D and the rigid cavity of dibenzo-18-crown-6 contributed to the selective adsorption of Ag(l). The adsorbent keeps high capacity (about 39.8 mg/g) and selectivity for Ag(I) adsorption after three regeneration cycles. This new composite adsorbent is promising in extracting trace levels of Ag(l) from unconventional wastewaters containing high concentrations of interfered ions.

• 出版日期2017-4-1
• 单位福州大学