Reusable carbon dot/chitin nanocrystal hybrid sorbent for the selective detection and removal of Cr(VI) and Co(II) ions from wastewater

The last few decades have seen a dramatic increase in heavy metal ions in industrial wastewater, especially Cr6+ and Co2+ ions, which have been shown to adversely affect human health; thus, there is a great need for their removal. Existing removal methods are time-consuming, expensive, and require high technical skills; therefore, there exists a need for a quick, simple, and cost-effective method. Chitin was selected from natural materials (shrimp waste), and an inexpensive, biodegradable, fluorescent carbon dot/chitin nanocrystal (C-dot/ChNC) sorbent for the simultaneous detection and removal of heavy metal ions from wastewater was synthesized from it. C-dot/ChNC shows high selectivity and sensitivity to Cr6+ and Co2+ ions and has high chromium(VI) and cobalt(II) adsorption capacities. These ions are weakly adsorbed on the C-dot/ChNC surface and are easily removed during regeneration, showing high cyclability. Thus, C-dot/ChNC is a viable sorbent for the removal of heavy metal ions during wastewater treatment. An optically active carbon dot/chitin nanocrystal hybrid sorbent for the simultaneous detection and removal of chromium(VI) and cobalt(II) heavy metal ions from wastewater is presented. Isotherm studies show that adsorption is weak and chemical in nature and this advanced functional material has high adsorption capacity for these ions. The hybrid also exhibits high cyclability. [Display omitted]