Cellulose nanofiber-based nano-collector for highly sensitive preconcentration, spectrophotometric detection, and efficient recovery of Co(II) ions in lithium-ion battery waste

Abstract

Using cellulose nanofibers network and surface, a state-of-the-art nano-collector was fabricated in this research to pre-concentrate, detect spectrophotometrically, and recover Co(II) ions from lithium-ion battery waste. The inherent environmentally friendly nature of cellulose nanofibers CNF, coupled with its unique surface characteristics, establishes it as an excellent substrate for immobilizing the (E)-4-((4-dodecylphenyl)diazenyl)-2-nitrosonaphthalen-1-ol (DPAN) chromophore. The resulting CNF-DPAN nano-collector demonstrates exceptional sensitivity to Co(II) ions in aqueous media, exhibiting an impressive limit of detection as low as 1.12 ppb (1.91 × 10−08 M), enabling efficient naked-eye sensing. The CNF-DPAN nano-collector changes its color from yellow to deep red quickly when exposed to varied Co(II) ion concentrations, with a reaction time of under a minute. Furthermore, the developed CNF-DPAN nano-collector proves highly effective in the recovery of Co(II) ions from lithium-ion batteries, offering an interesting solution to address the pressing environmental concerns arising from lithium-ion battery wastes while concurrently serving as a viable recovery strategy for valuable Cobalt ions. The adsorption capacity of the CNF-DPAN nano-collector toward Co(II) ions was investigated and found to be 198.25 mg/g, while the recovery of the Co(II) ions from the lithium-ion batteries waste was up to 75 %. Moreover, the developed CNF-DPAN nano-collector can be reused up to six times with high efficiency after treating the CNF-DPAN nano-collector with 0.1 M HCl.