Optical and quantitative detection of cobalt ion using graphitic carbon nitride-based chemosensor for hydrometallurgy of waste lithium-ion batteries. (February 2023)

• Record Type: Journal Article
• Authors: An, Byeong-Hyeon; Lee, Tae-Gyu; Khan, Tamal Tahsin; Seo, Hye-Won; Hwang, Hyun Jin; Jun, Young-Si
• Is Part Of: Chemosphere. Volume 315(2023)
• Publication Date: 2023-02
• Subjects: Carbon nitride -- Cobalt ion -- Optical sensing -- Photoluminescence -- Waste battery recycling; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2023.137789
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: A hydrometallurgy is one of the most important techniques for recycling waste LIBs, where identifying the exact composition of the metal-leached solution is critical in controlling the metal extraction efficiency and the stoichiometry of the regenerated product. In this study, we report a simple and selective optical detection of high-concentrated Co 2+ using a graphitic carbon nitride (g–CN)–based fluorescent chemosensor. g-CN is prepared by molten salt synthesis using dicyandiamide (DCDA) and LiI/KI. The mass ratio of LiI/KI to DCDA modifies the resulting g-CN (CNI) in terms of in-plane molecular distances of base sites including cyano functional groups (─CN) and fluorescent emission wavelength via nucleophilic substitution. The fluorescent sensing performance of CNIs is evaluated through photoluminescence (PL) emission spectroscopy in a broad Co 2+ concentration range (10 −4 –10 0 M). The correlation between the surface exposure of hidden nitrogen pots (base sites) and PL intensity change is achieved where the linear relationship between the PL quenching and the logarithm of Co 2+ concentration in the analyte solution is well established with the regression of 0.9959. This study will provide the design principle of the chemosensor suitable for the fast and accurate optical detection of Co 2+ present in a broad concentration range for hydrometallurgy for the recycling of waste LIBs. Graphical abstract: Image 1 Highlights: Heterogeneous fluorescent chemosensors are prepared by simple molten salt synthesis for hydrometallurgy of waste LIBs. Stoichiometric utilization of LiI/KI enables to prepare the graphitic carbon nitride-based all-in-one chemosensor (CNI). CNI-based chemosensors achieve a selective optical sensing of Co 2+ in the wide concentration range of 10 −5 –10 −1 M.