Pollution of heavy metals in water remains an unresolved environmental problem demanding for the development of efficient water purification technologies. This work demonstrates the green modification of graphene bio-sponge for heavy metals adsorption consisting of alginate bio-polymeric network encapsulated with magnetic reduced graphene oxide and functionalized by tetrathiol precursor using photoinitiated thiol-ene click chemistry. The well-engineered tetrathiol modified graphene bio-sponge (SH-Graphene bio-sponge) was grafted with bountiful micropores, oxygen functionalities and high density of sulfur-containing groups (10.2 at % S) with high binding affinity towards Cd (II) and Pb (II) ions. SH-functionalized graphene bio-sponge showed outstanding adsorption capacity for Pb (II): 101.01 and Cd (II): 102.99 mg/g, surpassed commercial and several literature reported adsorbents in highly competitive selectivity studies using co-existing heavy metal ions (Cu, Co, Pb and Cd) spiked- sea water. The tetrathiol modified bio-sponge also exhibited remarkable stability and reusability feature with only 0.015 mg/L Pb (II) detected, after five repeating adsorption-desorption cycles using mixed heavy metal ions solution and acidic eluent, complied to the strict US EPA maximum contaminant level (MCL) for lead. This work contributes promising solution towards the development of environmentally-friendly, energy-efficient and sustainable functionalization approach to develop adsorbent for efficient uptake of heavy metals in water.

Multithiol functionalized graphene bio-sponge through photoinitiated thiol-ene clicked chemistry for heavy metal ions adsorption

ACS Fall 2020 Virtual Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.