Thiol-ene click chemistry synthesis of a novel magnetic mesoporous silica/chitosan composite for selective Hg(II) capture and high catalytic activity of spent Hg(II) adsorbent

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 405; p. 126743
• Main Authors: He, Haifeng, Meng, Xiangying, Yue, Qinyan, Yin, Weiyan, Gao, Yue, Fang, Pai, Shen, Liang
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.02.2021
• Subjects: Adsorption; Catalytic transformation; Chitosan; Hg(II) ion; Magnetic mesoporous silica; Thiol-ene click chemistry; Magnetic mesoporous silica; Hg(II) ion; Catalytic transformation; Thiol-ene click chemistry; Chitosan; Adsorption
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2020.126743

[Display omitted] •A new nanocomposite (MMS/CS) containing CS, thioether and MMS moieties was developed.•Thiol-ene click reaction was applied to overcome the drawbacks of cross-linking method.•The MMS/CS exhibited selective Hg(II) capture and excellent adsorption ability.•Hg(II) loaded spent adsorbent could be utilized as an efficient catalyst. Development of multifunctional bioadsorbents by a simple method for selective capture of the toxic Hg(II) from aqueous media, and subsequent reuse of the spent Hg(II) adsorbents as efficient heterogeneous catalysts are of great interest but remains a great challenge. Hence, in this work, a novel magnetic mesoporous silica/chitosan (MMS/CS) composite was facilely synthesized via the thiol-ene click reaction strategy to overcome the drawbacks of conventional cross-linking methods. The obtained materials were characterized by FTIR, XRD, SEM, XPS analyses. The uptake of Hg(II) by MMS/CS was systematically investigated under different parameters. Kinetic studies indicate that the sorption equilibrium can be reached within 20 min and sorption process fits well to the pseudo-second-order model. Sorption isotherm is well described by Langmuir model with the maximum sorption capacity of 478.47 mg/g at 298 K. Which represent a better Hg(II) uptake capacity and rate than the concerned materials previously reported. Besides, the coexisting ions exhibit little competition effluence on Hg(II) uptake. What’s more, the Hg(II) loaded MMS/CS can be used as an efficient catalyst to transform the phenylacetylene into acetophenone with yield of 98.3%. Therefore, this work not only demonstrates thiol-ene click reaction is a new and facile method for preparing chitosan-based functional materials with promising uptake capacity for Hg(II), but also provides a new approach for reusing of Hg(II) adsorbed material for catalytic application, thus expand the application of chitosan and magnetic mesoporous silica in diverse scientific fields.