Systematic Modulation of Thiol Functionalities in Inexpensive Porous Polymers for Effective Mercury Removal

• Published in: Chemistry : a European journal Vol. 28; no. 72; pp. e202202340 - n/a
• Main Authors: Wongwilawan, Sirinapa, Kim, Doyun, Nguyen, Thien S., Lim, Wonki, Li, Sheng, Yavuz, Cafer T.
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 27.12.2022
• Subjects: Adsorption; Adsorptivity; Aquatic environment; Chemistry; Contamination; covalent organic polymers; Drinking water; Functional groups; Health risks; Mercury; Mercury - chemistry; Polymers; Polymers - chemistry; Porosity; Porous materials; post-functionalization; Selectivity; Sulfhydryl Compounds - chemistry; Sulfur; Sulfur - chemistry; Sulfur content; sulfur grafting; sustainable water treatment; System effectiveness; Water discharge; Water treatment; Wettability; wrapping mechanisms; covalent organic polymers; sulfur grafting; sustainable water treatment; wrapping mechanisms; post-functionalization
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.202202340

Through accumulation, mercury contamination in aquatic systems still poses serious health risks despite the strict regulations on drinking water and industrial discharge. One effective strategy against this is adsorptive removal, in which a suitably functionalized porous material is added to water treatment protocols. Thiol (SH) group‐grafted structures perform commendably; however, insufficient attention is paid to the cost, scalability, and reusability or how the arrangement of sulfur atoms could affect the HgII binding strength. We used an inexpensive and scalable porous covalent organic polymer (COP‐130) to systematically introduce thiol functional groups with precise chain lengths and sulfur content. Thiol‐functionalized COP‐130 demonstrates enhanced wettability and excellent HgII uptake of up to 936 mg g−1, with fast kinetics and exceptionally high selectivity. These Hg adsorbents are easily regenerated with HCl and can be used at least six times without loss of capacity even after treatment with strong acid, a rare performance in the domain of Hg‐removal research. Triple trickle trap: Mercury cations were captured by three thiol‐modified porous polymers with precise sulfur content and chain length. Results show optimized binding with very high capacities and a unique hydrophobic/hydrophobic interplay with multidentate binding facilitates varying capture kinetics. Easily scaled up, these inexpensive solids could feasibly be used in cleaning mercury‐laden water streams.