Sustainable waste-derived cellulose-based nanosensor for cobalt ion detection, removal, and recovery from industrial effluents and battery wastes

This study introduces an eco-friendly approach to detect and remove Co(II) ions from electroplating effluents and lithium-ion battery wastes using a cobalt nanosensor (CNS). A repurposed cellulose template which was recovered from wastepaper (CNFsWP) was decorated with 1-(2-hydroxy-1-naphthylazo)-2-naphthol-4-sulfonic acid (HNNSA) ligand molecule, resulting in a highly sensitive and selective CNS. Through rigorous optimization, the CNS's performance is maximized by considering factors like pH, sensor amount, reaction time, probe concentration and temperature. Advanced characterization techniques, including XRD, SEM, TEM, and nitrogen adsorption, confirm the porous structure of the cellulose carrier, crucial for efficient cobalt ion capture. DFT calculations further explain the molecular interactions between the cellulose and Co(II), validating the selective binding mechanism. The fabricated CNS demonstrates an exceptionally low detection limit for Co(II) down to 1.13 × 10−7 M, making it a talented candidate for practical applications in electroplating wastewater treatment. This sustainable solution offers a significant step towards mitigating heavy metal contamination and promoting environmental sustainability. [Display omitted] •A sustainable cellulose-based nanosensor (CNS) was synthesized using nanocellulose (CNFs)•The CNS demonstrated high sensitivity, selectivity, and stability for the rapid detection and removal of toxic Co(II) ions•UV-Vis spectroscopy confirmed the detection of Co(II) ions with a detection limit as low as 1.13×10-7 M,•CNS was applied for the removal of cobalt ions from electroplating wastewater•Computational studies provided insights into the structural properties of the CNS ligand and its Co(II) complex