Synthesis of covalent thiourea organic polymer (CTOP) and adsorption of au (III) ions.

Due to the rarity of gold as a noble metal, efficient and selective Au (III) ions adsorption is critical for gold recovery. Since gold is thiophilic, in this paper, a new covalent thiourea organic polymer (CTOP) was prepared by introducing thiourea reactive groups into the covalent organic polymer of enaminone and applied to the adsorption of Au (III) ions in aqueous solution. The synthesis of the new material was confirmed by SEM, TEM, XRD, and XPS tests. Thanks to the abundant thiourea chelating sites in the CTOP, the total adsorption capacity of the material for Au (III) ions is up to 2372.7 mg/g. In addition, in mixed ionic solutions containing Au (III), Cu (II), Co (II), Cd (II), and Ni (II), it has strong selective adsorption performance for Au (III). It is worth mentioning that the CTOP material still maintains high adsorption performance after five adsorption cycles, which proves that the adsorption material has good reusability. The adsorption kinetics were investigated using pseudo-first-order and pseudo-second-order kinetic models, and the results showed that the adsorption was chemisorption. According to the experimental results of adsorption kinetics and thermodynamics, the adsorption process of CTOP for Au (III) ions conforms to the quasi-secondary adsorption model and the Langmuir adsorption model. We believe that the study of efficient adsorption of Au (III) ions by this new covalent thiourea organic polymer is of great significance for the development of gold recovery technology. [ABSTRACT FROM AUTHOR]