Selective capture of silver ions from aqueous solution by series of azole derivatives-functionalized silica nanosheets

作     者：Shanshan Mao Tao Shen Qing Zhao Tong Han Fan Ding Xin Jin Manglai Gao Shanshan Mao;Tao Shen;Qing Zhao;Tong Han;Fan Ding;Xin Jin;Manglai Gao

作者机构：State Key Laboratory of Heavy Oil ProcessingCollege of ScienceChina University of PetroleumBeijing 102249China Unconventional Natural Gas InstituteChina University of PetroleumBeijing 102249China 

出 版 物：《Chinese Journal of Chemical Engineering》 (中国化学工程学报（英文版）)

年 卷 期：2023年第57卷第5期

页      面：319-328页

核心收录：

学科分类：083002[工学-环境工程] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 081702[工学-化学工艺] 08[工学] 0817[工学-化学工程与技术] 

基　　金：the National Natural Science Foundation of China (21776306) 

主　　题：Organo silica nanosheets Adsorption Silver ions Selectivity Mechanism Waste treatment 

摘      要：The introduction of bifunctional groups into low-cost adsorbents for selective adsorption of Ag(I) through synergistic effect will have a profound impact on the recovery of precious metals. Organo silica nanosheets(organo-Si NSs) functionalized by series of azole derivatives(2-mercaptoimidazole(MI), 2-mercaptobenzimidazole(MBT) and 1H-1,2,4-triazole-3-thiol(MTT)), are fabricated and employed for selective removal of Ag(I). The structures of the organo-Si NSs are investigated using several characterization methods. The results of batch adsorption experiments display that the maximum adsorption amounts are 70.3, 103.2 and 139.5 mg·g^(-1) on MI-Si NSs, MBI-Si NSs and MTT-Si NSs for Ag(I) ions, and reach rapid equilibrium within 10–30 min. The adsorption processes are chemisorption and fit pseudo-second-order kinetic model and Langmuir adsorption isotherm model. Notably, MTT-Si NSs is greatly selective for Ag(I) in multicomponent system, and the distribution coefficient value of Ag(I) ions reaches 2331.26 ml·g^(-1). The reusability of organo-Si NSs is verified by four cycles of regeneration tests with 0.1 mol·L^(-1) HNO_(3) as the eluent. A combination of experimental, structural along with theoretical analysis is conducted to proclaim the structure-adsorptivity relationship:(i) The adsorption mechanisms are attributed to complexation.(ii) The amino group and sulfhydryl group of MTT-Si NSs as well as MBISi NSs may have synergistic impacts on Ag(I) capture.(iii) The differences in adsorption behavior and selectivity of the three organo-Si NSs are mainly related to the form of function groups, charge density and steric hindrance of adsorbent. This work not only sheds light on the promise of functionalized organo-Si NSs for the rapid and selective removal/enrichment of Ag(I) ions in complex water systems,but also provides new insights for designing cost-effective Si NSs-based adsorbents.